Boat Builder Central - Builder Forums

I intend to keep editing this first post to reflect the progress of my boat. This way, anyone interested just has to look at the first post to see the history and status of the boat.

If you have any questions, feel free to email me at jasonmcintosh@yahoo.com

Jason


First, current status:

Sept 2004. Enjoying the boat. Here's another picture in the 10,000 Islands, which is the northern part of Evergladed National Park. Sept 2004. You can see my two Wallgreens umbrellas and my daughter on the boat. Fun.




Now the history from the beginning.

I got the plans in May, 2003 and after a several weeks decided to go ahead and build the boat. I got the epoxy and plywood from Jacques’ in early June and started drawing the cuts on the wood and doing some cutting.

Here’s the side panels cut and already fiberglassed together. The stringers, front transom and internal frames area also cut and laying around somewhere in this picture.
<img src ="modules/Upload/jasonmcintosh/panels_cut_on_floor.jpg ">

This is the rear transom cutout and the three 1/2" thick pieced glued together to make a very heavy 1.5" thick transom. The plans showed the center section to be curved, but I wanted it flat for the motor clamp. I also added a raised "tab" for mounting a rear trolling motor, but I'm thinking that I put it too far out. Haven't coated the wood with epoxy yet.




Here’s the 4 hull pieces cut and fiberglassed together. Flipping these big pieces was tricky as they’d want to fold when they were only fiberglassed on one side. For this reason, I first put two long (16’) pieces together, flipped them and fiberglassed all four pieces together. This way, when I flipped the entire 16’ long by 6.5’ bottom hull panel, only one seam (the 16’ one) wasn’t glassed. I clamped a 2x4 to the panel to give it some support while I flipped it, which helped quite a bit.
<img src ="modules/Upload/jasonmcintosh/hull_bottom_panels.jpg ">

Unfortunately, the digital camera was off on vacation while I assembled the frame, put the sides on, flipped the assembly, and put the bottom panel on. But here it is sitting on the temporary support bed for it. The seams have already been filled in, rounded off, and fiberglassed.
<img src ="modules/Upload/jasonmcintosh/hull_side1.JPG">

Same point in construction, but different angle trying to show the entire boat.
<img src ="modules/Upload/jasonmcintosh/hull_side2.JPG ">

And one from the front trying to show the width. That’s a yard stick on the boat in front of the 1 gallon epoxy jug.
<img src ="modules/Upload/jasonmcintosh/hull_front.JPG ">

Laid the glass cloth on the bottom. Going to do both sides at the same time. <img src ="modules/Upload/jasonmcintosh/hull_w_glass1.JPG ">

Quick tool for marking off 6” around the cloth.
<img src ="modules/Upload/jasonmcintosh/six_inch_marker_tool.JPG ">

And the cloth after it was trimmed.
<img src ="modules/Upload/jasonmcintosh/hull_w_glass2.JPG ">

I put the 10’ runners on the bottom and sanded the fiberglass so that it was ready for the microballoon and Quickfair fairing compound.
<img src ="modules/Upload/jasonmcintosh/hull_sanded_w_runners.JPG ">

I put the microballoon stuff on first to fill in the fiberglass weave, and then used Quickfair. All in all, I didn’t know what I was doing. Hopefully fairing the interior will go better. I ended up using my entire gallon of microballoons and a 1.5 quarts of quick fair. To completely finish off the bottom (all the way to painting that is).
<img src ="modules/Upload/jasonmcintosh/hull_bottom_faired.JPG ">

This is my 2nd coat of microballoon fairing stuff on the sides. I eventually just coated the entire side to eliminate any wood grain that would show through the paint, however that may have been a waste of time since the System 3 primer is pretty good at filling in voids the size of grain. On the other hand, I'm very happy with the resulting fairing job, so maybe it made all the difference. I'll probably never know.
<img src ="modules/Upload/jasonmcintosh/side_2nd_fair_coat.JPG ">

The boat’s pretty much faired at this point and I’m gluing the rub rails on. I ended up putting 2 coats of epoxy over the boat with light sanding using 220 grit on a 5” random orbit sander) after each coat. Sanding the shiny epoxy after fairing really made the big scratches in the fairing material show up. I put the 2nd coat of epoxy on in an attempt to fill them in, but that was pointeless as the System 3 primer would have filled them in just fine. After this, I started painting…
<img src ="modules/Upload/jasonmcintosh/gluing_rubrail.JPG ">

Four coats of primer (light sanding after each one) finally covered the bottom pretty well. Used an entire gallon of the System Three primer.
<img src ="modules/Upload/jasonmcintosh/hull_primed.JPG ">

I didn’t like any of the System Three stock colors, so I bought their white Topcoat paint had the local Home Depot tint it. However, things didn’t go well. The color that I ended up with was much lighter than what I wanted (almost a baby-blue), so I took it back and had them add as much pure blue tint as I thought that the paint could handle. The result was this strip. At $100/gallon I cried for a few days before I decided to give it a shot and just paint the boat and see how it looks.
<img src ="modules/Upload/jasonmcintosh/strip_color.JPG ">

And here’s the result: BLUE! It’s not as bad as I thought it would be, but it’s a lot BLUER than what I originally wanted. Sometimes you’ve just got to “go with the flow” and enjoy the “richness” events addeto your life, whether you'd like them too or not. That’s the way I’m trying to take this…

<img src ="modules/Upload/jasonmcintosh/blue_hull.JPG ">

This was taken after the hull was flipped. On the left is the internal frame that the hull had been sitting on, in the middle are two old area rugs that we set the boat on as we turned it over, and then finally the trailer where it’ll sit until it hits the water.
<img src ="modules/Upload/jasonmcintosh/flip_setup.JPG ">

Picture showing the nice curve of the bow.
<img src ="modules/Upload/jasonmcintosh/on_trailer.JPG ">

One more side view after being flipped.



My transom design. The tab thing on the starboard side is for a trolling motor. I expect that my son will want to spend his time on the casting deck, so I needed to put a trolling motor on the back, but there wasn’t any place for it. I think I put the tab too far out though. Would probably have been better in a 3 or 4 inches.
<img src ="modules/Upload/jasonmcintosh/blue_transom.JPG ">

My son took a picture of me in the boat. It’s about 6.5 feet wide where I’m at. Hard to see that in the pictures though. I’m 5’5”, so I can easily lay crossways if I want.
<img src ="modules/Upload/jasonmcintosh/jason_in_front_boat.JPG ">

Shot of the bare interior from the front.
<img src ="modules/Upload/jasonmcintosh/rear_interior_w_transom.JPG ">


I didn't get a chance to take pictures of the internal frame as it went together. Here's a picture of it sitting on the support bed after flipping. The stingers are made from 1/2" CDX (?) glued together to yield a 1" thick stringer. The two center frame pieces are made from cheap 1/4" plywood I had around. Since the sole is going in, these frames are only used to shape the hull during its construction.
<img src ="modules/Upload/jasonmcintosh/frame_after_flipping.JPG ">


The fiberglass’s been put in the bottom and the frame tabbed in, and now I’m putting in the cleats for the casting deck. I’m glad I’m back to cutting some wood. Much more fun for me than fiberglassing.
<img src ="modules/Upload/jasonmcintosh/gluing_castingdeck_cleats.JPG ">

It’s now the end of September, so from June till now has been 4 months since I started. Actually, I didn’t work on the boat for one entire month, so it’s been 3 months of most of my evenings and a good chunk of my weekends working on it. Hope to be fishing in 2 months or so.

Back to work. Here's the casting deck being test fit. I've added a small hatch in the front for storing an anchor. The casting deck is 6'4" wide at the widest point, and runs 5' along the length of the boat. Nice and big.
<img src ="modules/Upload/jasonmcintosh/fitting_the_casting_deck.JPG ">

Here's the aft deck being fitted in place. I've carved out quite a bit of space for hatch acces to the seat storage area. I'm hoping that it won't reduce its strenght too much. I plan on putting a 13 gallon above deck tank in the rear-most port side compartment, which is the reason why that hatch is as big as it is. The hinges for that hatch will go directly into the transom.
<img src = "modules/Upload/jasonmcintosh/fitting_sern_deck.JPG ">


It's Janurary 2004 now. Had to take a bit over 2 months off from the project.

I forgot to add these pictures before, so their a bit out of order. This shows the hull interior after the seams have been fiberglassed.


Hull interior during fiberglassing interior surface.


Built an "anchor locker" for top access from the casting deck. Didn't want to make it clear across the bow so I could possibly store longer items under the casting deck on either side of the anchor locker. That was the thinking anyway.



This is a platform I built to hold the trolling and starting battery under the sole. I hope to put the batteries there to get some weight in front, but after finding out how heavy of cable I'll need for the starting battery (2Ga would be best) I'm not sure I'll put the starting battery up here. The batteries place a significant load on the hull at the tip of the stringers, so I'm going to secure it to the underside of the casting deck.


The hull is foamed! I used 6 gallons of foam... The stringers and cleats have epoxy glue on them ready for the sole to be laid down. I ran just one large PVC pipe from front to back for electrical lines.

Note that I didn't use the center seat frames for the sole and wall reinforcements. I used some cheap plywood for the initial framing that the hull was built around, and then just use some pine boards to reinforce the sole where the pedistal seats will go. Unfortunately this meant that I didn't have the 3" wide stiffeners that run up the sides of the boat. Instead I added them just above the sole (see pictures futher down). This caused joint between the 3" stiffeners and the sole to be weak and crack after takign the boat out into 1' chop. Ah, I should have followed the plans closer, but I didn't want to waste that center frame material, but I should have at least ran the 3" stiffeners down the wall to the bottom of the hull.


The casting deck is glued and fiberglassed in place. I also painted under the casting deck as much as I could before I secured. I'm using Whidbel White. The sole is also glued down and coated with epoxy.


Sole glued and epoxy coated. There's three holes for pedestal seats plates.


The rear seat and motor well area showing the floor in the seat storage area. Most of the hatch covers are lying on top of the seat frames.


This is the console I designed for the boat. It's 31" high and 31" wide and was a pain to design. It's a lot easier to be able to just follow the plans rather than trying to come up with your own design.


The console is only 12" long which kept it's foot print small, but it gave me some concern about how strong it'd be. So far it seems very strong..



Here's the hull with the final coat of epoxy on it to seal the microballoon fairing material and saturate the wood where I sanded it down to the wood during fairing. Nice and shiny! This got another light sanding before putting the primer went on which dulled it considerably.


It's March 7th and I just finished putting the final coats of paint on the boat! The hull is done! I don't have picts of it yet, but here's two showing the hull primed and ready for the final coats. I'll get picts of the finished boat when I can pull it out of my garage and get some good shots of it. Now I need a motor...






April 4, 2004: The boat's done. Here it is at the end of my driveway, just before we left to take it out for the first time. I've only got one of the 3 pedistal seats in. That chair is actually going to go behind the console. I have yet to buy the three for the actual pedistals yet.



Here I am in the water trying not to worry about everything that's not perfect with the boat. (The loaf of bread on the casting deck was for feeding the fish...)



And putzing around by the dock.



Unfortunately, the boat porpoised too much to get the boat on plane for long, and I didn't bring any tools along to adjust the motor's running tilt, so I can't say how it handled under way. We were restricted to just plowing through the water and using the trolling motor. Caught some fish, had fun.

The last last picture above shows the nose sticking up rather high. It did that (and worse) while the motor was anything above an idle. When not running, the boat sat pretty flat in the water. This, despite the motor (40 HP 4 stroke), me, the gas, and a battery in the back. (I have one large trolling battery under the front casting deck though.) Even with my wife and 6 year old son on the casting deck, it still porpoised badly. I think my wife briefly left the deck once.

Hopefully the motor is an easy fix and I'll be saying more about how the boat feels at 30 MPH or so next week.

About the interior color I chose: System Three’s Whidbel White. I’m very happy with it. While it looks really creamy on their color chart (and in my garage) I couldn't really tell that it’s not white when I was out on the water. And the fact that you don’t get the glare that you’d get from Orca White makes it a great choice. At first I didn’t think I’d like it, but I didn't like any of S3's other colors and after my BLUE experience I wasn't going to mix my own! But now I’m extremely glad I chose it.

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Working on the porpoised problem. I tilted the motor back to its farthest position (i.e. moved the prop in closer to the transom). This help alot, but still not great. I added 150 lbs of sand bags to the front, which helped sum, but still not great. I put the trolling motor on the front transom, but I didn't like how much it vibrated when I hit some 3" chop, so I moved it back to the aft transom.

Next I added an SE 300 hydrofoil to the motor's ventalation plate. Here's a picture of it. This has helped quite a bit. I can not get up to 20 mph w/o porpoising, but I'd like to get 30 mph out of the boat. I think the next thing I'll try is raising the motor to the next set of bolt holes.



I added a plug to the side of the boat so I could empty any water that gets into the main floor space area. Its located just above the sole infront of the rear seats. When sitting still, water would _just_ come up to this level, and at 20 MPH the water spray covered it. At least it'll let water out when the boat is on the trailer.


My first prop was a chewed up one of unknown pitch. Probably 9" or 10", with a 10.25" diameter. I changed it to a 10" diamter prop with a 15" pitch. This got the boat up to 20 MPH @ 4000 rpm, but it didn't want to go past 20 mph. I'd push it to 5000 rpm, but the speed only climbed to 22 mph w/o much wind. (Actually, if a good wind was at my back, it'd go to 27 mph, but it'd start porpoising.) Never was able to get the motor past 5000 rpm (max is 6000 rpm).

The boat seemed to start pushing against some "wall" past 20 MPH. I think that the hull is OK (i.e. flat). Going to need some ideas on what to do next.

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I moved the motor up two bolt holes, which I'd guess is 2". The motor would ventelate just a little bit once in awhile, so I'll leave it at this position for now.

Moving the motor up reduced "the wall" effect quite a bit, but it's still there. I could at least get to 25 MPH @ 5000 RPM, but the motor couldn't go past 5000 RPM. I've still got the 15" pitch prop on. I'm going to replace it with a 13" prop for the next outing.

I think that if I were to trim the motor out (move the prop away from the transom), it'd reduce "the wall" effect even more. Unfortunately, this will also make the porpoising worse. To reduce the proposing I currently have:

1) the hydrofoil on the motor's ventilation plate
2) the motor trimmed all the way in
3) 60 lbs of dead weight in the bow "anchor locker"
4) the motor moved up about 2" above the transom

Along with my 6 year old boy in the fore-port chair allows me to cruise 20 MPH w/o any porpoising. This is pretty close to being acceptable performance for just the two of us.

One of the first comments Jacques made when I reported that the boat was proposing and that my ventilation plate was just under the hull was that I should raise the motor. Once again, he was right.

OK, now for some fun. Pictures...

This is a view of my aft layout. It's kind of a "birds-eye-view" that lets you see most of the back of the boat, but the view is a bit off from raising the camera above my head. The 3rd pedestal seat isn't in. I'd go behind the seat you see on the right.


And a birds-eye-view of the bow.


Full view of the boat's interior from the front.


Quite a few "Florida water buffalo" were out today...


And this is a view of the canal with the boat pullup up on the bank. We climbed onto a bridge to take the picture. I thought that it was a nice view with the boat.



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Another week and another set of test results. Put a 13" pitch prop on the boat and took it out on Lake Okeechobee. Hit about 1' chop. The anchors were almost jumping out of the forward anchor locker, so I had to put them under the casting deck. The boat took the chop just fine, but it was definitely rough. Running on plane very doable though. One problem I had though was that the waves would cause air pockets to travel under the hull. The flat bottom combined with the runners funneled the air back to the motor which would effect the prop. The motor was constantly revving due to them. So, if I want to operate in waves that big, I've got to lower the motor, which will bring back "the wall" effect.

A jack plate and power trim would be ideal... Heck, a hull with a selectable deadrise would be nice to...

WOT with the 13" pitch prop only got the motor up to 5300 rpm (6000 is red line) and a speed of about 25 mph. I used my power tilt to trim the motor up a bit. The boat shot up to 30 mph, but started porpoising immediately, so I could only hold it there for a few seconds. Didn't get a chance to look at the tach during those few seconds. Not sure what to do with the prop now... Drop down to 11"?

I’m definitely going to put a gas tank under the casting deck. Probably a 12 gallon low profile from Tempo secured to the underside of the deck. I’m a little worried about the fuel foaming though. I’ll keep the ability to put the 13 gallon tank in the rear, so I’ll have plenty of fuel for a full weekend’s worth of sightseeing.

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Suffered my first minor damage to the boat. This is a bit complicated to describe with text, but I'll try. The sides of the walls have two stiffeners on each side of the boat. These are supposed to be cut down from the middle two frames that would have been for the center seat in the non-sole version of the boat.




However, I didn't put those two seat frames in, and so I didn't have these stiffeners. What I did instead was to put pine board supports under where I was going to put the pedistal seats, and I just added some 3" wide boards to the sides to take the place of the stiffeners that would have come from the center seat frames. I figured that since I almost doubled the size of the rub rail, and since I put the sole in, it wouldn't be a big deal to just add the "side stiffeners" later.

When I took the boat out onto the 1+' chop on Okeechobee, I let the boat pound fairly hard. The next time I took it out, I noticed that there was a crack in the sole about a 1.5" long and a half inch out from the forward, port side stiffener. The crack ran parallel with the side wall. Apparently, the boat bends enough to cause the walls to flex in and out. This puts an enormous amount of strain on the fiberglass joint I made at the bottom of the stiffener where it's glassed to the sole. Enough stress to cause the glass to pull up on the sole and generate a crack. Had I made the stiffeners according to the plans, the stiffener would have run all the way down through the sole to the bottom part of the hull, and this joint at the sole would have been much stronger.

Also, when I fiberglassed the bottom of the stiffener to the sole, I only fiberglassed out along the wall, not away from it. Let me try to explain. The stiffener is 3" wide and made from 3/8" thick plywood. When I fiberglassed it to the sole, I only ran fiberglass along the 3" sections, so the fiberglass only extended 3" away from the wall. I didn't fiberglass out from the 3/8" section (how can you?), and so only 3" of the sole had glass on it (that is,the glass extended only 3" away from the wall).

When the wall flexed, and the stiffener pulled on the sole, the glass only pulled on 3" of the plywood, and the plywood probably separated and cracked. Had I extended the fiberglass more than 3" out onto the sole, it may have had enough strength not to crack.

So what I'll probably do is to sand all around the bottom of the front-port stiffener and reglass all around the stiffener and sole area so that it grabs more of the sole and makes that joint stronger. If that cracks too, I'll have to somehow add more structure to that area, or maybe put a metal plate in with some screws down into the sole so that it grabs more than just the top ply of the sole.

All in all, this is a minor problem. Had I followed the plans, it probably wouldn't have happened. And I'll probably just have to take it easier on the waves...

***

Finally fixed the cracks (sept 2004). After I sanded the area, it showed that the first ply from the plywood broke.

I got a lot of good advice on how to fix the boat. Mostly to cut up the sole and put the internal frames back in. However, in the end I decided not to do it. I decided to stick with my first inclination and just reinforce the area around the bottom of the stiffener. I put down a layer of fiberglass that ran out several inches from the stiffener, put a 1/4" board over that to spread out the load, ran two "blossoming" sheet metal screws through the 1/4" board and 1/2" sole to spread, added several layers of fiberglass on top of all of that, and the result (before painting) was:



I took the boat out in 2-4' waves after the fix (just went 5 MPH though), and the boat's fine. I think I'll live with the fix. I'm thinking that the extra flexibility of the hull might actually make it last longer, who knows...

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I took the boat out into the 10,000 Islands, which is the northern part of Everglades National Park. I'd been told that there's lots of nasty stuff to hit if you don't know your way around, so I put my old prop on whose pitch I don't know. I got the boat up to around 27 MPH at 6000 RPM with the old prop. Unfortunately even in the 1' chop (or maybe a bit less) the boat gave too rough of a ride for my wife and I had to slow it down to 15 MPH, pretty much the slowest it'd go and still be considered on plane. After going 27 MPH she asked "why is this wall moving so much?", referring to the wall with the crack at the bottom of the stiffener...

Well, we had a GREAT time on the water. Going out, I went slow as hell and didn't hit anything. We played around on a little beach on one of the keys. Here's the boat parked there. The umbrella was $25 from Walgreens. Quick, cheap, and adds at least some shade to the boat. And look at those colors!



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Took the boat out into the gulf around the 10,000 islands again. Had something closer to 2’ waves this time, but having grown up in the 10,000 (small) lakes of Minnesota, it’s hard for me to judge just what you’d call the wave size. The waves were to rough to get up on plane with my family on board (four of us all together) directly into the waves, but were able to run at about 20 MPH a an angle into the waves. Hit a few waves about 3’ high dead on at about 7 MPH which gave the boat quite a shake. Made my family quite nervous and caused the stiffener on the starboard side to crack near the sole just as it cracked on the port side. The adventure continues...

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Sept 2004. Back to the 10,000 islands. You can see my two Walgreens umbrellas and my daughter on the boat. Fun.



Some comments after using the boat for about 5 months now. . .

The whole layout was to provide deck space for a tent for camping. So far I’ve only done that once, so it hasn’t really been worth it. Hopefully this will change though. The console also makes it impractical to put a regular bimini top on since when you fold one down, you’d want it to go right where I put the console. My umbrellas are actually working out well though, and they don’t get in the way for fishing.

The direction that the boat goes is really effected by the weight distribution on the boat, so with just me in the boat the side console makes it track a bit sideways. When my wife moves from one side of the boat, the boat will change direction by 15 degrees.

With a 10” diameter, 10” pitch prop, I can get about 27 MPH from my 40 HP 4 stroke when the family is on board (wife+2 kids, coolers, etc.). When I’m alone, I can do about 22 MPH w/o porpoising. It’d be nicer to go faster, but when the chop gets over 6”, my wife can’t take the pounding. I can go about 20 MPH in 6” chop before it’s too much for her. In 1’ chop, I can do about 15 MPH.

When the waves get 2-3’, I’ve got to slow down to 8 MPH or less. The front end really pounds on those big waves.

We hit some 4+’ waves the last time we were out. We were just going 5 MPH with my daughter on the bow casting deck having a blast. We weren’t in a hurry, but we probably couldn’t have gone faster than 8 MPH in those waves anyway.

The rub rails are getting dinged up. I decided to use them for what they were for and just let the wood “rub”, but I find myself wishing I had put something over it. I’m going to keep an eye out for some rubber molding or maybe some wood strips that would be easy to replace.

Salt water fishing is making a bait well a necessity. I’m going to be looking for something that I can put in the front. I don’t have a good place for a water supply line though. I wish I would have designed something into the boat while I was building it.

Getting the boat completely dry is a pain. Under the casting deck, there’s a 5” step up to the sole. This fills with water. Easy enough to get out, but I wish I would have just had a drain to the back so I didn’t have to bother with it. The back two storage areas on either side of the motor well don’t have the sole in them, so they go all the way down to the hull. I drain the cockpit into the starboard one, and keep the fuel tank in the port one. Both have drain plugs, but that leaves 1/4” of water in them, which has to be wiped out if I want it to get completely dry. I wish I had a solution for that. In hindsight, it would have been best to slope that area so it would have drained better to the drain plug.

Living in South Florida, I keep wanting to go off shore, but this boat just isn't something you want to do that with, especially with my limited experience and a 'concerned' wife. In the end, perhaps a C17 would have been a better choice for us. But this is a great boat for 1' or less chop. While I've found it to handle well in 3-4' waves, it not a boat you could run from a storm in those conditions.

Jason

Great job so for Jason. I can't quite tell from the picture ... what color is your boat?

Jason,

Excellent series! She's really coming along nicely. Can't wait to see the interior done. Are you building it with the raised sole and center console?

-Dave

As always, thanks for the nice words and encouragement.

I'm putting in the sole, but the console is going to be off on the starboard side as far back as I can put it. I'll be sitting on the rear bench while operating it. I plan on putting three pedestal seats in the other corners of the sole, and also a seat on the bench where I'll be sitting. I wanted to keep the sole as open as possible with the hope of someday putting a small tent up on the boat. The center console would have ruined this, but it certainly would have made for a nicer “pure boat”. I hoping that moving the console over and back doesn’t screw up the center of gravity too much. I’ll be putting a 13 gal portable gas tank in the rear port seat locker, and one or two batteries under the casting deck, so that should bring some balance back.

Jason

Put more pictures into the first post and wanted to bump up the thread. Jason

Thanks for the update. Looks like your are on the downhill run to completion. The boat looks great!

Chris
OD18

Thanks Chris. Yeah, I can now pretty much count on one hand the remaining big things to do before it’s done. Exciting, but sad to think that one day I won’t be spending my late night evenings in my garage… Going to miss the place, but I’m not done yet.

Jason

Looks really nice Jason, now i can see what my boat will look like.
About the console, i have tha same plan to be sitting on the rear deck, but don't you think that you(me), console and fuel tank all in the rear half of the boat won't raise the bow to much, up to a point that you can't look over it?

Another question is: why did you offset the pieces of frame that had to go underneath the sole? i've just lined them up just as the frame would be in 1 piece.

Chiel,

Thanks. It's been fun to build it, but it's taken far longer than I wanted it to.

I don't know how bad all that weigth in the back will be. That's why I wanted to move the batteries up there. Originally I was going to try and put a gas tank under the sole, but my brother-in-law talked me into a portable tank instead. I'll just see how it turns out.

I didn't use the center frames for the sole support. I just added some solid pine pieces in later. The ones on the outside of the stringers will be directly under where the pedestal seats for support. This will reduce the effectiveness of the hull side supports that I've yet to put in, but I think it'll still be OK.

Jason

Nice pictures Jason.

Takes quite awhile to load up on a dialup connection, but worth the wait. If you put lots more pictures in, maybe put links in instead, and then dialup users could open each picture in a separate window while they read the notes from the previous picture?

Or maybe reference the Picture number in the user gallery and one could have the text in one window on the left, while clicking through the pictures on the right? I re-numbered most of my pictures in the gallery album to try to get them to show up in some sort of logical order when clicking on the next arrow. There are a few yet I need to fix that are out of order.

When you start adding all the water borne pictures, and fish landings, and fish strikes, and the addition of the hydraulic Infrared controlled gaffing hook/harpoon gun, well, by then it may take half an hour to loadup on this connection. I'm not DSL or Cable user at this point.

Love the pictures. Nicely done.

*Hey! You're building a boat! You can't do that. I mean, Can people really do that? I mean like normal people? * ... so I was told by a client when they saw a picture in my briefcase.

sincerely,
ks

Jason

Looks like you've done a great job on your boat. I'll bet you're getting excited now. I know I did when I got done to the end of that long tunnel.

Gary

jason, thanks for the pictures and the storyline.
i've been watching your progress for some time and you have convinced me to take the first step with the gf-18 through ordering the plans as of 5 minutes ago. its not exactly what i had in mind to go after those big flatheads and blues in the cape fear river but its the closest thing to what i want. once i get the plans and see what i'm dealing with i can make a decision to build per plans or tweak it.
keep up the good work and i think you've done a fine job.

mark

jason, i like the white interior. alot of people dont like white because of glare but i wear sunglasses anyway during the day. most of my inshore or inland fishing is done at night and a white interior means you need less artificial light to find that leather glove you dropped on the floor after landing that 60 pound flathead.

Splash!

Looking good Jason!!! Nice job

but the hight of the bow worries me a bit, can you still look over it?. Could you give me an estimation of the amount of weight in the back(Motor, fuel you, batterie, trolling motor etc..)

I'd like to know this so that I could put some more weight in the front. Maybe you just have to put some ballast in the front?

Can't wait to get mine wet!!!

Sweet!!!!!!!!!!!!!!!!

Very nice. I'm always amazed at how "small" the boats look while under construction -- and then how BIG they become once in the water. That is a really great boat.

Awesome!

Unfortunately, the boat porpoised too much to get the boat on plane for long

The reason for that is the weight distribution. The console as you have it is not as we designed it.
We carefully calculate weight distribuation on all our boats.

We are always willing to give advise about changes.

The way to correct that is to move the center console.

Jason the boat looks fantastic. Nice neat job. Best of luck with her.

chiel,

There's quite a bit of weight in back: motor 220 lbs, me (190 lbs), starting battery 30 lbs (?), 13 gallon fuel tank (only had 6 gallons in it which I'd guess at 30 lbs, not sure). I have one largish (50lbs?) trolling battery under the casting deck.

Even with this weight distribution, the boat sits fine in the water. The nose isn't high at all and I can easily see over the bow when not underway. However, when I give it some gas, the bottom of the boat sinks and the nose comes WAY up and there's NO WAY I can see over it. I didn't try standing though.

Ryan said the porpoising is due to too much weight in back. Could cause some of it, but at this point I'm pretty sure most of my problem is with the "attack" angle of the motor. As soon as I got home, I tilted it as far "back" as it'll go. I'll just have to see how much that improves things the next time out. Even with my wife and son on the front of the casting deck (200 lbs total?), it didn't help the porpoising much.

If need be, I'll move the starting battery up front. Maybe the fuel tank, but I'd hate to do that.

The cavation plate on the motor is probably just under 1 inch below the bottom of the hull. I don't know if moving that down would help this problem or not. I'll make the easy changes first.

Fritz,

Actually, the boat seemed bigger in my garage, but then the whole project has become larger than life over the many months working on it.


Thanks for everyone's comments. This board has been great!

Jason

The weight distribution is the main culprit.
The boat looks very well built, congratulations, but now let's make it run decently.
Weights:
I remember the first Cigarette 42 that we fitted with twin Merlin diesels. We had the same weight problem: we looked like Flipper the dolphin walking on his tail each we tried to get on plane. The first day, we took 5 heavy people and put them on the foredeck just to get on plane! Later we added big trim tabs and learned to play with engine trim.
In your case, I would move that console forward otherwise you will never be happy with the performance. That console looks much further back than on the plans. If you do not want to move the console, move as many weights as you can forward: tank, batteries and even put some cement blocks under the casting deck. Block them so that they don't jump and down and go through the bottom!
We counted on max. 160 lbs for the engine which is the weight of a 40 HP. (That boat will plane with a 25 an 3 persons onboard.)
Engine settings:
1" below the bottom is a little deep and may contribute to the problem. Raise it until the cavitation plate is flush with the bottom.
Trim: try to tuck the engine in, under the boat. That should push the bow down.
Last resort:
Hull wedges . . . I hate it but it will compensate somewhat for the weight.
We'll talk about that if the other solutions are not acceptable.

Jaques, How about trim tabs rather than wedges ???

Jacques,

That's not what I wanted to hear. What do you think of possibly putting a shim between the engine and the transom to get the engine to lean back more? Don't know if I'll do it, but wondering if it's a possibility.

I thought that I saw in the motor manual that the cavation plate should be 1.5" below the hull. Did I get this wrong? Is it better to have it right along the hull?

Moving the starting battery up is very doable. Gas tank is possible, but would really suck. Moving the console is the last thing on my list, even after dead weight.

What's a hull wedge?

Jason

As Kurt says, trim tabs would be easier than wedges.
Wedges, shims, shingles whatever the name are like fixed trim tabs added to the hull, underneath, at the edge of the transom.
Maybe somebody can word that better . . .

A shim to trim the engine may also help but try to adjust things first.

Just for curiosity, next time you launch the boat, take sand bags with you to try different weight distributions.

Jason I did a search and found a product called " Smart Tabs ". They make manual trim tabs and they come in various sizes depending on motor and boat length . They cost about $50. If your motor movement does not solve the problem you might want to experiment with these Smart Tabs to see if they solve the problem. You may have play around with them and fix their position somehow( that is why I say experiment). If they did work, I would then invest in the Bennet Trim electric tabs. (Although they don't mention it the Smart Tabs seem like they would be a problem when reversing the boat up since they are always set in a downward position.)P.S. I had the opposite problem on my PH16. My nose would not come up and the solution wound up being a Stilleto SS prop. This is after playing with the motor height a few times. Now the boat performs better than I ever imagined. I have all the confidence that your problem will be solved as well.

Thanks Kurt. Those "smart tabs" seem to be around $150 and involve using pneumatic "shocks" to push down on the tab for low speeds, and allow them to come up at high speeds. I hate to spend that kind of money an have no idea whether they'll work or not.

Why did you prop make such a difference for you? I haven't tried to optimize my prop yet, but don't see why it'd contribute much to this problem.

And I'll be bringing some sand bags with me on the next outing as Jacques suggested.

Jason

I thought I saw them discounted for less. In any event I would look for products similar to the smart tabs that perhaps you can experiment with. There must be ones that you can set in various positions. I am highly confident that tabs will solve your problem. When I was a kid I had a boat that would not plane off. My father welded up a pair of adjustable trim tabs and instaled them on the boat. They looked very similar to the smart tabs but you had to fix them into a set position. He gave me enough adjustment holes so that I could manualy adjust them depending how many people I took. They were crude but they solved the problem. As far a Prop's go, I found out that there are three types of SS props. There are Bow Lifters, Stern Lifters and Boat Lifters. I was initially using aluminum and I went the the SS Bow lifter. It made a big change in the attitude of boat at higher RPM's . My bow would dig down after I got over 4,500 RPM and my electric trim could not make the bow come up. With the new prop I can now trim the bow up. There are Stern Lifting props but I did not read about them and do not know if they would help in solving your problem. I would first do everything Jacques suggests since he has been there,done that and seen it all.

"What do you think of possibly putting a shim between the engine and the transom to get the engine to lean back more?"

First let me say Im impressed and excited to finally see a Garvey 18 in the water. Awesome!

But.......
I agree, you have a center of gravity problem. Move EVERYTHING you can as far forward (and to port side if possible?)as you can, (tank, battery, anchor?, trolling motor). When you built the console where did, you moved the center of gravity aft. Nothing too major, but, a tradeoff.

Buy one of those adjustable jackplates (Non-hydraulic). It will both raise and push the whole motor back a bit. They arent too expensive. Also, sounds like you need to trim the motor down or in probably about as far as you can get it. If you can get an adjustable jackplate, start with the cavitation plate level with the bottom oc the hull, try it, and adjust up as needed. That along with moving your battery, tank, and whatever else you can as far forward as possible should fix the porpoising.

Get on ebay and do a search for trim tabs. There were some listed that are self ajusting as you described also listed were some that you could lock into various positions via a adjustment knob. Plus the usual more expensive models.

Congratulations Jason! It came out really sweet. I hope you can get the porpoising under control and get some good data on performance soon. I still like the blue.

-Dave

Holy "peep" that's definitely NOT what i wanted to hear. I do have a 7 gallon fuel tank under the castingdeck and i haven't fitted my console. i was planning of putting it at the same place as yours but i'm going to have a look at it again.

I'm going to run it with a 2-stroke motor so the weight will be less and the engine is also equipped with big fins on the cavitationplate to increase planing(decrease planing speed).

If i were you jason i'd first try the fins on your outboard. They are relatively cheap and could even be made by yourself.

Good luck!!!

Based on your comments I assume you do not have electrically adjustable trim on the engine. You need to try moving the motor down/in with the manual trim adjustments before you start doing anything drastic. If it has some rocker like you indicated in another post you may have to add trim tabs or wedges (built in hook) but play with the weight distribution and your trim adjustments first.

Doug wrote:If it has some rocker like you indicated in another post you may have to add trim tabs or wedges (built in hook) but play with the weight distribution and your trim adjustments first.

It doesn't sit on the bunks flat, but easily rocks on them. I'm quite sure that this is apart of the design. Perhaps Jacques put too much of a "reverse hook" into the design. I don't know. I adjusted the motor as far "forward" (or back depending on your perspective) as it'll go and shifted some weight forward. I'll be going out tomorrow to give it a try and will report how it went.

Thanks for everyone's thoughts.

Jason

Jason,

Really beautiful boat! The blue turned out very nice. Good luck solving your planing dilema.

chiel wrote:Holy "peep" that's definitely NOT what i wanted to hear. I do have a 7 gallon fuel tank under the castingdeck and i haven't fitted my console. i was planning of putting it at the same place as yours but i'm going to have a look at it again.

I'm not panicing yet. I’ve only got one outing on the boat and a number of options for improving the situation. At this point I’m still determined to keep the console where it is. The fin is a good idea. I’ll keep it in mind.

Jason

Not to derail this thread, but I see grant is from college station. If you could shoot me an email to johnlee@golfconnectionusa.com

Thanks

John Lee West

BTW, there is no rocker (reverse hook) worth mentioning in that design .
The last 6' are absolutely straight. A little bit of rocker appear at 8' and becomes around 1/2" at 10'.
Take a straight edge to the plans, it is clear.
This maybe another possible explanation for the planing problem: you may have too much rocker.
The fact that the boat rocks on the bunks is an indication.
Let's check something: with the boat flat on the trailer, transom touching the bunks, what is the gap between the bunks and the bottom at 6' then at 8'.
If it is more than 1/4", it probbaly plays a role in the problem. In that case, fixed trim tabs, wedges or a Doelfin will help.

I took yesterday off and went fishing with my son in the everglades canals. We had a great time catching lots of pan fish and some small bass. I love the boat layout, even though it’s killing its performance.

Before I bought it out, I trimmed the motor as far back as it’ll go, moved the starting battery (35 lbs?)from the back to the front, and put three 50 lbs bags of sand on the very front of the casting deck. Since my wife wasn’t with me, the sand pretty much replaced her weight from the first trip.

With my son (50 lbs) on the casting deck, I was able to get the boat up on plane w/o bouncing at somewhere between 1/2 and3 /4 throttle, but it would bounce if I went faster. Maybe I was going 20 MPH, but I’m just guessing. If my son got off the deck, I’d have to back off a bit.

Another annoying problem is that the boat goes a bit sideways, bow to port, stern to starboard. I’m going to try to compensate for this using the trim tab (anode thing) on the motor, but it may be due to me sitting well off center.

As far as handling goes, the boat is pretty solid. I didn’t get the foam sealed to the sole, so there is a little vibration in the sole that would have been nice to have eliminated, but other than that it’s an excellent boat. When taking corners, the boat does tend to slip sideways. The 1”x1” runners probably help, but right now I’m thinking that it would have been nice to have them 1.5” high rather than 1”. But of course this is supposed to be a shallow water boat, so that’s defeating the design a bit.

When I pushed the motor up to 3/4 throttle (past? not sure), the warning buzzer would sound. I assume this is the engine saying the RPMs are too high. The prop I put on the motor is just a used one from another 40 HP motor. I don’t know its pitch. I’m assuming that I’ll need to buy one with a greater pitch, but I could use some suggestions here. I mostly bought the 40 HP motor to ensure that the boat planes with a full load, not to go super fast. Is there a guide for the size and pitch of prop you need? How do you measure the pitch of a prop? The prop has so many curves, it’s hard to see one single angle.


Next steps:

It seems that I’m going to have to move the trolling motor up front. Don’t want to do it since I’ll have to blunt the nose on the boat (more work), and I’ll have bought 40 feet of 6 Ga wire for nothing. But every pound of weight I can move from back to front is worth two pounds of added weight in the front.

I like the idea of putting fins on the motor. Are they mounted to the cavation plate? Does anyone have experience with them?

Since tipping the motor back helped, I’m thinking “more is better”, so the idea of putting shims between the transom and motor mount is becoming more attractive to me. But there must be a limit to how much you can tip the motor w/o suffering other problem. Comments? Worth a try? I’ll do some measurement and maybe take pictures of where the cavation plate is relative to the hull and post them when I get a chance.

Jacques:

I believe that the back 6’ of the boat is flat, but the 17.5’ boat doesn’t sit on the last 6’ when it’s on the trailer. It sits more in the middle, which is why it rocks. I’m expecting that my three 2x4 bunks will eventually sag and reduce this, but for now it’s rocking.

All:

Again, and again, thanks for everyone’s help. Your comments are greatly appreciated.

Jason

Whe you say trimmed the motor back as far as it goes do you mean tilited the prop out or in? Also, did you raise the motor on the transom? The AV plate should be no lower than the bottom of the boat. Sometime you can get away with it being higher.

That buzzing is probably the motor overheating. With the motor trimmed way up (prop out as far as it goes) it may not be getting enough water. You should have a tach to figure out your rpm's. I don't think a buzzer would go off when you go over the recommended rpm. On newer motors it has a rev limiter on it but not older motors. If it is the temp, do not run it overheating. You will ruin the motor quickly. Sorry.

Keep us posted & we'll get it figured out for you.

Dave,

I'm bringing the prop in, toward the transom. Previoulsy the prop was back, which put a slight downward force on the transom. Pulling the prop in should level this out, or perhaps push the transom up a bit.

I haven't EXACTLY measured the plate's position relative to the bottom of the hull. I'm thinking that it's a bit lower than the hull, but now that I moved the prop in, it's looking pretty close to being level with the hull. Perhaps it's a half in lower?? Not sure.

It'd be easy to move the motor up one set of mounting holes. That's probalby an inch or more, so I think that the plate would end up being above the hull. This is worth trying?

It's a 2003, 4 stroke motor. The buzzing seems to occur at a certain throttle position. If I give it more gass, it buzzes. If I back off, the buzzing immediately stops. If it was from heating I'd expect it to take awhile to cool down, so the buzzer wouldn't go off so quickly. I've only reved it up like this 2 or 3 times though.

>Keep us posted & we'll get it figured out for you.

Thanks. Sounds like a deal...

Jason

It sounds like you have the trim in as far as you can so that will help a lot. Raising the motor should too. Do you have a manual for the motor? If so, maybe it says what causes the buzzer to go off. I really don't tink it's the rpm's and is the temp but could be wrong. If the manual doesn't tell you, try iboats.com. They have a great forum & lots of experts that can answer just about any motor question. I think its best to get the buzzing figured out in case its something bad for the motor and go from there.

Be patient, we'll get it.

OK, it's getting better.
Glad to hear that you tucked the engine under the boat, I misunderstood at first.
You can trim it further with a transom wedge. They sell those things a little bit everywhere. It is a 5 degrees wedge that you use to tuck or trim up. It cost around $ 120.00. If you can't find it, email Joel:
shine@e-boat.net
and he will put one up at BoatBuilderCentral.com

Next steps:
- Doelfin or similar
- fixed trim tabs
- bottom wedges

The last solution is the least expensive but requires some fiberglassing.

Bottom: I would still check. Yesterday, I posted from memory but Ryan checked and the bottom profile shows a 1/4" rocker at 8'.
That means that as designed, if you put a straight edge on the bottom from the transom, there should be a gap of less than 1/4" at 8' from the transom. I say less because as in many of our boats, we take the shrinking of the resin in account and expect a straight bottom to result from that very small rocker.

Performance in turns: it's a flat bottom boat . . .

If you're thinking of this:

http://www.iboats.com/mall/index.cgi?prod_id=21995

Looks like a great, simple, cheap ($31) fix if it will help.

Jason

Jason,

Sometimes there are known (to the manufacturer) issues with their buzzers and bells. You might want to ask the manufacturer about it. I have a 2003 Nissan 4-stroke that has a constant electrical hum within a certain rpm range, it is caused by a missing electrical diode cover or some such thing, that is a known issue. Of course, rather than fix the problem before they sell it to you, they want me to bring it in for service. My engine also has alarms for oil pressure and heat. The oil pressure buzzer goes off if I don't prime the engine properly before starting. Of course, an oil pressure warning in the middle of operation would concern me.

Now that you have it running fairly well at least, I would get the prop sorted before any other surgery. It can make a huge difference as many have found out.

I had a Carolina Skiff for a few years. It shares some of the GF18 design attributes. Mine was 19'with a 65 Suzuki/power tilt and trim. I think your working on all the right things but I wouldn't do any mods while having 150lbs of sand in the front unless you can have it installed permanently:) I think those manual tabs sound good. Dialing in the prop (with a tach) is important, as is correct motor height. The right prop will help hold your boat up. I felt my boat porpoised for a couple of reasons. It probably never had the ideal prop. -Also it does not split the "wind" very well. I think that has some lifting effect on it. Of course it can't go up forever or it would be an airplane, so it goes up-comes down. I could generally fix this with trim. Also don't expect it to track well at speed in a corner, it's basically a "skimboard". Just the nature of the design. Tucking the motor in will keep the bow down but there are times when you will need to ride bow up to keep from getting wet. In a head wind the CS would hit a wave - send a wall of water forward which then would be blown back over the boat......!!! Can you say WET! Never bothered me but passengers love it. All said I really liked it - simple, stable, shallow but a compromise. Why don't you drill some holes in your floor and pour some more foam in there?

Dave

Jason,

The runners under my GF18 are 1x2" Do you think this would give the "grip" you're missing?

I haven't fitted my console yet, so I'll probably move it forward a bit.
The fins are mounted to the cavitationplate by drilling something like 4 holes of 6 mm. When using this big fin, you have to keep the motor under an angle to the transom or else it won't generate any lift, just play with the angle and find the right one.

Good luck!!!

Beware of too much "grip". It can produce wild sideway movements, uncomfortable.
It's just part of a wide flat bottom boat. It handles differently.

Really beautiful, and excellent work, Jason! I'd be very curious to know about noise while anchored. Hull slap is a sore point for many flats boats. How is the noise while anchored, or while using your trolling motor.

BTW, I've been researching and reading a lot of good things about those Smart Tabs. Hope to put a set on my boat for the holeshot.

5-0

I think Doug is right about the prop. Get that right first. The local marine parts store I've been going to wants $133 for a tach plus $33 for some sort of "pigtail" connector. Another $33 for the motor's shop manual, then $140 or so for the prop... I think I've found my "hole in the water" where all my money goes.

macfiveo: Thanks for the compliments. I've only had the boat out in the canals and there's been very little wind, so I don't know what the wave slap is like quite yet. As Dave mentioned about his CS, when I did get a gust of wind I was surprised how much the bow caught it and was pushed around by it. More reason to have more weight in front I guess.

chiel: I don't know if 1"x2" runners are better or not. I must say that I felt very little "grip" from the 1"x1" runners I do have when I take corners on plane. I'm sure there's helping though. Big lesson so far is to get as much weight forward and centered in the boat as possible. I've taken a hit in performance for my layout, but I'm still expecting that I can get it to work for what I want the boat to do. I've got a starting and trolling battery under the front deck. I don't think that your 7 gallon tank will do much, expecially since on average it'll only have 3 gallons in it.

About the fins, what do you mean that "you have to keep the motor under an angle"? The fins must be below the hull? I saw them in the store for around $50. A great price if it'll significantly help the performance.

I'm not too keen on spending $150 or so on smart tabs. macfiveo, if you put them on your boat, please let me know what you think of them. From what I've seen, they've only advertized them for low speeds, not for planing conditions. Am I wrong?

Planning to take it fishing again tomorrow as is. Hopefully I'll have a tach next weekend, and the right prop the weekend after that.

Jason

Forgot to mention, some propeller manufacturers stamp the diameter and pitch on the outer part of the exhaust ring, or on the "shaft" part of the prop were the blades are "attached" to. Again...usually...hope that helps

Jason, what I mean by that is if you want the fins to create vertical lifting force the propeller has to be tucked a little bit under the boat so that the waterflow can hit the fin under an angle and can exert pressure on the underside of the fin, which will create the liftingforce that will push the back of the boat up.

Took the boat out for the 3rd time today. The only mod was turning the "trim tab" behind the prop to correct for the fore-port, aft-starboard sideways pull effect when planing the boat. Unfortunately it didn't help. However, I did find out that if I steer from the center of the boat, it'll go straight. So this sidways effect seems to be due to my console placement as well.

So Jacques and Ryan's comments about the console being in a poor location seem to be holding true. I still love the layout, and will continue to see what I can do to improve the situation. But others are advised to follow the center console design if you want the best motoring performance.

This time I had my wife, daughter, son and the three 50 lbs sand bags on the casting deck. (I think of the three sand bags as "Jacques", "Ryan" and "Fritz". Can't wait to get rid of them...) I got the motor up to full throttle before it'd just start bouncing up and down a bit. Including the two batteries under the deck and a 15 lbs anchor, I'd guess that the total weight in front was around 475 lbs. However, if the family comes off the casting deck and sit in the two front pedistal seats, then I have to slow it down a bit to avoid the bouncing stuff.


Other than wakes, still haven't gone through any significant waves. Got a bit more wind this time, that produced maybe 3" chop in places. With the family and the "bateau crew" on the casting deck, the wind didn't effect the boat at all and it took the chop very well. We've rented 12' aluminum jon boats with a 10 hp motor in this area before. The 3" chop would just pound those jon boats to the point that my family demand that I take the boat off plane. But they all happiily laid on the casting deck while the GF18 went through it.

The paint is taking a beating. Even with just three trips on it, my wonderful blue paint has been scraped down to the primer in 10 sizeable places or so. Hate to see it happen, but better a boat that's used than one that collects dust.

Well, I hope you're enjoying reading my experiences with the boat. I think it's great for fishing.


Jason

jason, with independent trim tabs you can compensate for the weight of you and the console being on the side.
it would be really nice if a prop change will solve alot of your problems.
i'm still shopping materials for my gf-18 but i hope to start ordering and building soon. i'm currently doing the big no no around here by lengthing it by 10%. its alot of effort and alot of extra material for a mere 1.75 feet but thats still cheaper then a new 19 foot carolina skiff.
keep us posted on your progress .

Jason,

If you haven't committed to the tach yet, you can save some money installing a "tinytach" for about $40. It only takes a few minutes to install. I got one for my outboard and it's great to have, especially when trying to get the prop right. I haven't seen them in the stores, but you can buy from the manufacturer at http://www.tinytach.com/tinytach.html.

Smilinmatt,

What outboard do you have and which model Tiny Tach works for you?

This product is unique in that it offers a way to find the rpm of engines that do not have alternators or battery powered electrical systems. Plus it is cheap and seems easy to install. The only problem I see is that the battery is encapsulated. After 5 years, I guess you throw it away and get another one.

JerryF
GV11+

The tiny tachs work great. I just put one on my boat. If you're not sure which one to get, don't worry. When I called to order, I wasn't sure which one I needed and got someone who helped me out. Just tell them what you have & they send you th correct one.

I added two pictures to the 1st post in this topic. One shows a hydrofoil that I added to the motor to help with the porpoising problem. You can read the comments I left.

In a nutshell, the good news is that the hydrofoil definately helped with the porpoising, but the boat doesn't want to go past 20 mph. You can read my comments in the 1st post.

Other than raising the motor, not sure what to do about it next. I can try adjusting the motor's angle more...

The 15" pitch prop that I have currently have will get me to 20 mph at 4000 rpm, but then the boat hits a "wall". 5000 rpm only gets me to 22 mph.

I'm thinking of getting a 13" pitch prop, but the problem seems to be "the 20 mph wall" rather than the prop pitch. I'd appreciate some ideas on what to do next.

Also, after putting the hydrofoil on, I've noticed a high pitch sound coming from the motor. It's not too loud, but any little sound is troublesome to hear. I don't think it was there before the hydrofoil, so I'm wondering if it's placed too much stress on the motor that it wasn't designed for. The prop is new too, so it could be caused by either the hydrofoil or prop.

jason

Jason,

You have GOT TO get the tach and work on prop sizing if performance is bugging you. The difference between 5000 and 6000 RPMs could be 10 mph. You need a prop that will allow that motor to get at least within 200-300 rpms of red line while lightly loaded. All the other stuff is window dressing in my opinion. Power trim helps with this setup process. If not you have to pick a nice anti porpoise trim setting and live with it. hope this helps.

I agree with Jim W, you need a tach to get the rpms set correctly first. Raising the motor one notch may add 200 rpm also.

Thanks guys. I guess I didn't explicitly say it, but I do have a tach now and a Humminbird fish finder with the speed sensor, so I know how fast I’m going.

I’ve got to say this: the fish finder will take the speed and compute how far you’ve gone. I put on about 30 miles on Sunday, buzzing around fishing, etc. So cool. Sure it’s probably not super accurate, but at least it gives you a number to think about. So cool.

Anyway, I’d like to target a top speed of 30 mph. If 4000 rpm is giving me 20, then 6000 rpm should give me about 30 with this prop (20*6000/4000=20*3/2=30 by simple ratios). Because of this, I’m not inclined to give up on the 15” pitch prop just yet.

Unfortunately I don't have power trim. Wish I did.

Again, I suspect that if I find out what’s causing the resistance “wall” at speeds over 20 mph, then the prop will rev up to 6000 rpm at the light load.

Jason

What rpm are you getting at WOT now?

Always forget to mention something...

She won't go past 5000 rpm with the 15" pitch prop. The old unknown pitch prop would allow the engine to redline at 6000 rpm, but I didn't have a speedometer on then. She get's stuck at 22 mph @ 5000 rpm going into a wind (10 mph?), but will go up to 27 mph with that wind to her back.

Right now, the motor is titled so that the ventallation plate (plus hydrofoil now) lifts up on the back of the boat. That is, the plate isn't parallel with the hull, but the foot is in toward the transom a bit. This lift is probably what's helping with the porpoising, but my be causing "the wall" at 20 mph.

I remember reading about other people having motor problems, and now here I am...

jason

The same thing happens to my C19. If I trim for bow down for fast planing it won't go over 35 or so. As I trim higher, if there is any waves at all, they will start the boat prpoising as the bow comes up and speed and RPM increase. Top speed is only available in calm water here at highest trim angle there are no wavelets to start the porpoising. Without power trim, the boat would plane slower, cavitate in turns, and top out 5 mph slower. It is the nature of fixed trim angles, no getting around it. Pick your best compromise of trim but get a nice cupped SS prop that turns at 5800 WOT.

Oh yeah, and the prop is aluminum. Prop shop wants $110 for Al, and $260 for SS. Didn't want to spend the money on a SS, at least not yet. Obviously you think it's worth it...

If I remember correctly, your max rpm is 6000. If so, I would use the other prop. Outboards do not like to be lugged.

Dave: Yes, max rpm is 6000. I plan on keeping the old prop for a spare but wanted one with higher pitch for more speed. I'm still pondering whether I should drop down to a 13" pitch or less. Maybe bringing the motor up 1" and going to a 13" pitch would be the next best thing to try.

BTW, I guess you'd say that the old prop has a "cuped" blade as it goes rather flat near their ends. This is for better low end push?

jason

Cupped blades do not go flat near the ends. The have a noticeable "cup".

The cupping acts like a low gear to more low end push. If you're already running low RPM's a cupped blade would really load up your engine.

FWIW I've found some good deals on SS props on eBay. You have know what you're looking for and be patient.

What ever you do, I would suggest you get your rpms as close to 6k as possible. The motor will live a longer and happier life.

If you are willing to buy a stainless prop from your local dealer he will probably let you try several different pitches and blade styles and blade counts. My local dealers have let me experiment on two boats. Michigan wheel has a great prop called a ballistic that looks odd but it works awesome. The more blades the better the prop will hold the nose up on plane, at least on bass boats. fewer blades get more speed

Jason, don't you think the problem is in your amount of horsepower? Jaques said that it would plane with a 40 Hp, but didn't state anything about the speed.

Does anyone know if Jaquess has built a GF18 and tested it? If so, that sure would help. I'm putting my console in this weekend and try to get it in the water soon.

I'll let you know when she's afloat.

Good luck in the meantime!!

chiel,

I don't have any experience with this stuff, but I think that the problem is primarily just what Jacques and Ryan said before: weight distribution. I'm guessing that my current "20 mph wall" is due to the position of the motor that I chose to reduce the low speed porpoising. I'm not sure what the correct terminology is, but the motor foot is in, which is pushing the stern of the boat up a bit when it runs. Up to a certain speed, it helps, but the forces may become so great above 20 mph, that the motor just can't continue to push the boat forward and up anymore. This is amplified due to that hydrofoil I added. As jim said, power tilt would help adjust the motor to the optimal trim setting for the current speed/load condition. But with fixed trim, I've got to pick one setting and live with it.

I'll know more as I do more testing.

Jacques has not built a GF18. As far as I know, mine is the first one to hit the water. He's got lots of designing experience and is very confident with the design. It's also a pretty simple design, so doubt if he made any mistakes. Time will tell, but I'm not pointing a finger to Jacques yet.

After I posted my intensions to put my console in the back/side, I vaguely remember Jacques replying that it should go in the middle. I think that I'll eventually get the boat running ok, but as Jacques said, best performance would be obtained with the center console.

I hope I'm not giving the GF18 a bad reputation. I love the boat. I'm just off to a slow start. One piece of information that I wish I would have had was the fact that he designed the boat for a 160 lbs motor. I put a 230 lbs motor on it. It may have gave me enough motivation to put my gass tank under the front deck rather than in the back. But that's water under the bridge.

Where is your console going?

Jason

The chase tubing comes thru the sole in the same place as were your console is. I can still move it foreward a bit, but i do want to keep it at the starboard side so i can still have the big open sole. The engine i'm going (want) to use is a 55 hp yamaha which weighs around the 160 pounds you mentioned.

So i'm really eager to see if the 15 Hp more and the 120 pounds less have a big effect on performance. By the 120 pounds i mean 70 for the engine, 30 for the fuel which is in front and 20 pounds less for me

I'm not blaming Jaquess or anything, but it seams logical to me that if you design something you may want to test it first and then maybe make some modifications.

chiel wrote:I'm not blaming Jaquess or anything, but it seams logical to me that if you design something you may want to test it first and then maybe make some modifications.

No prototype and there is no need for it. After 100+ designs, I know how a boat with a very normal standard shape will behave.
And BTW, all designers know it, there are books about that and also software. I worked on boat designs in which we invested more than $ 1,300.000.00 without building a prototype!
The question should be reversed: if you do not follow the plans, consider your boat as a prototype and be ready to do some adjustments.
If you do not respect the plans, do not blame the designer. I know and can show with calculations why the GF18 will not work properly with the console aft.
There are basic laws of physics that you can not avoid: the CG wants to be over the resultant of the center of lift, hydrostatic lift and suctions. You can try to talk your CG in doing something else but it is not going to work.

If you don't believe me, build a prototype.
Put your console where we show it, use common sense inw eight distribution and the boat will perform as we say.

Jason is correct about his analysis: his boat is "hitting a wall" at 20 mph. Because of the trim, he doesn't have sufficient plane area to lift the boat higher and get the drag reduction that would result in a better speed.
Jason, you can test again, alone in the boat but with around 200 lbs in sand bags under or just at the casting deck. You'll get a few more mph that way.

jasonmcintosh wrote: This time I had my wife, daughter, son and the three 50 lbs sand bags on the casting deck. (I think of the three sand bags as "Jacques", "Ryan" and "Fritz". Can't wait to get rid of them...)

Well, I've been called worse things....

Jason,

When you hit your "wall", are you still producing a sizeable wake? When fully up on plane, your boat should have about a 6" wake. If you still have a large wake, you're not fully planing and the following could help:

With my "scale model GF-18", the GF-12, I have a 6 gallon tank under the bow seat and a 12v battery between the bow and mid seats.

When I'm by myself, if I sit on the back seat, the bow will start to porpoise at about 13 mph and by 15 mph it gets to the point where it's really pounding. If I move to the mid seat, the boat will ride at 22 mph (redline) without any porpoising. After it's on a plane, I can move slightly back (sit on a cooler between mid and rear seats) and reduce the throttle while still maintaining rpms (i.e. less hp).

When I have two people in the boat, I sit on the rear seat and the other person sits on the bow seat until it planes and then they move back to the mid seat (a small engine trick for getting up on plane easier and quicker).

If I was having your problems, I'd get a large friend to go for a ride with you. Have him sit as far forward as he can and see how it planes. After the boat planes, have him start moving back. You'll get an idea about how much you're going to have to move forward to get the boat to behave right.

If you're close to having the weight distribution right, you can stand forward of the console (holding the wheel) until it planes, and then move back to your seat.

Hope this helps.

its basicly the same principle as an airplane except the water is replaced with air. one thing for sure , if you dont respect the center of gravity in a plane whether it be a piper cub or a c5-a galaxy she aint going to fly.
take a trailer with a tongue weight of 1000 pounds and hitch it to a 1/2 ton pickup bumper. you get the same effect. nose high and every lane but the lane you want to be in.

Speaking of trailers, I'm having a bit of a problem with mine. If you look at my setup...



You're pretty much seeing the entire trailer. You can just see the hitch to the left. So you can see that the boat is pulled up as far as possible on the trailer and is completely above the wheels. I pulled it so far up to increase tongue weight as I was worried about having too much weight in back (at least I got that right).

Unfortunately I don't like how the trailer responds to my van's motion. If I make a somewhat quick turn left or right, the trailer will swerve back and forth for a bit before it settles down. I don't want to exaggerate the condition here. I think that for most driving it's just fine, but if I ever had to swerve hard (to save a squirrel or something) I’m concerned that the trailer just might flip. (Again, I don’t want to exaggerate the problem, I’m just getting my worrying done now before I take the boat on a 200 mile trailer trip. As it is now, I'm afraid I'd just have to run right over that squirrel...)

The trailer says it’s good for 2000 lbs, so I don’t think it’s a total weight issue. I’m thinking that the problem is mostly the fact that the boat is so high up on the trailer. There’s nothing I can do about that, but I can shift the boat farther back on the trailer. I think that I currently have plenty of tongue weight (I’d put it somewhere in the 150 to 200 lbs range) and wouldn’t mind reducing it a bit. However, I won’t do it unless I have some expectation that it’ll help how the trailer tracks the van.

So, does anyone have any thoughts on improving the trailer tracking by shifting some weight back?

jason

smilinmatt wrote:When you hit your "wall", are you still producing a sizeable wake? When fully up on plane, your boat should have about a 6" wake. If you still have a large wake, you're not fully planing and the following could help:

I think I'm getting up on plane. My wake seems much smaller than most boats that I pass by. (There's a flatulence joke here somewhere...) Maybe like half the height of most other boats. I suppose 6" is about right.

I appreciate the comments, and I'll keep the reports coming as I get more experience fiddling with the boat.

jason

Jason,

Regarding your trailering question, having as much weight on the tonge (forward not back) helps the trailer track better and makes it much more stable. As a rule of thumb, 10-15% of the total weight of the boat and trailer should be on the tonge (i.e. 1000 lb trailer, 100-150 lbs on the tonge). I would aim for 15%. I think that 12% is average and what most companies that build campers aim for. The same would apply to most anything. I pulled a uhaul once with too much weight in the back and couldn't go over 50 mph cause the thing would sway like crazy (should have loaded it better)

I have a freind with a coleman popup & he had to add more weight to his front storage compartment one time when we were traveling becuse it was swaying a lot. We put a couple 5 gallon jugs of water up there and his swaying stopped. This applies more to single axle trailers than multi-axle. On my travel trailer, I have twin axles and sway control so I don't worry about it too much.

On the trailer weaving it sounds like another CG issue. Narrow wheelbase and the boat mounted high is going to make it want to tip over causing the weaving. I think the squirel is going to have to be road kill unless you want to get a wider axle.

The trailer sway issue sounds more serious than just increasing the population of roadkill. The trailer should not be doing that even in a quick turn. High CG may be a cause but I think it is more likely a fore and aft balance issue. Correcting any imbalance will improve your towing situation.

You should find out the actual weight on the tongue (your guess may be way off). But even if you are in the ballpark on tongue weight, you also need to know how much the whole thing (boat and trailer) weighs. 10% is the minimum recommended but often boats are happier in the 15%+ range because the stuff in the boat can vary a lot.

Take the boat to a public scale and get it weighed. Just the boat and trailer by themselves (unhooked from the tow vehicle). Then weigh the tongue by itself (at the normal hookup height). Most scales out here will allow you to do multiple weights for the same fee if you ask for a time when they are not busy. You can also weigh the tongue at home using a bathroom scale but you still need to know the whole trailer figure.

If you have the total weight and if you know the trailer unladen weight, you will then have the boat weight. Knowning the boat weight may help you with your performance issues.

JerryF

Another thought, Is it possible to move the axle back? That would shift the CG farther forward.

Another trailer thought - much more way out there though...

How much does your boat weigh and how much are the springs on the trailer rated for?

Running the physics through my head (as I have never experienced the same phenomena), it seems that if the springs are rated for a much heavier boat than the boat on the trailer, a hard turn could make the boat heavier on one spring (momentum) and throw it back on the other a few times. Softer springs would not do that as aggressively.

Thanks for the comments about the trailer. Since tongue weight seems to be good, I’ll leave the boat where it is on the trailer. I noticed that I can get the boat to rock back and forth pretty well on the trailer’s springs. I think that this is causing a lot of the tracking problems as the boat likes to rock back and forth when I turn. Not sure what to do. Shocks would be nice, but the trailer isn’t made for them.

On a better note, I raise the motor and it reduced “the wall” effect quite a bit. I updated the first posting in this topic with my comments about the boat’s performance with the motor raised, and I added some new pictures of the interior. Next week I plan on trying a 13” pitch prop and see if I can get up to 6000 RPM.

jason

Thought I'd give a usage update.

I finally used the boat for camping this weekend. The approximate 6.5' x 6.5' area infront of the console fit a 3 man 7'x7' tent fairly well. Spent the night in the 10,000 island area.

The ability to put a tent on it was the #1 reason for my layout (i.e. putting the console way in back). I took a significant performance hit due to the layout, and I'm glad I finally got to use it that way.

Putting the passengers in front is not a good idea, especially for my wife who hates the pounding. I wonder if pushing the console all the way up by the front casting deck would have been better? Would have had more area in back, and would have put the passangers in the rear of the boat where the pounding would be much less.


Also, a few weeks ago, we took it about 2 miles into the ocean for snorkeling in the keys. 1-3 foot waves kept us around 10 to 13 mph. Still haven't fixed those areas where the fiberglass lifted off of teh sole. Just glad I'm using the boat...

jason

It worries me that you took the boat out in the ocean in 1-3 foot waves more than a mile out with those significant building errors (omissions) we discussed a while back. That's all, it just worries me.

JimW wrote:That's all, it just worries me.

It's of concern to me as well, but I'm taking it easy and keeping an eye on the boat. One of the things I love to do is to learn how things work (big part of the reason why I went into (electrical) engineering). The cracks (or fiberglass separation from the sole) have been a learning experience about how these boats flex.

jason

Very nice dude,like the color.Excellent workmanship.Evild

Evildwarf wrote:Very nice dude,like the color.Excellent workmanship.Evild

Thanks. It was a fun project, but with these boats the fun never ends as you fix and add new stuff...

Over the last two weeks I had the C19 under a 20X10 canopy for it's annual rework period.
- Touched up the bow area where I learned about (1) proper trailer bow eye height, (2) why a hold back strap is good to have so stop signs don't push the bow into the trailer bow roller and damage the bow.
- Fixed the bow storage areas so they drain completely and use standard sized (extra) bilge plugs.
- Cut anchor locker "doorway" bigger to allow for anchor storage (I hate the way that anchor looks up there).
- Primed and painted inside of quarter seats (couldn't see in them it was too dark).
- Primed and painted my two transom corner fixes that were exposed before.
- Tapped and bolted console rail attachments to reduce lowest idle RPM resonance (noise) that drive me crazy.
- Made and installed some primitive rope handles to the cheap quarter seat and front console seat hatches that broke off the first day I had them!
- Gave her a nice thorough cleaning. She hates the mess I make when we hunt shrimps together!

To do:
- varnish the wood coaming to prevent epoxy fade.
- rotate trailer tires (and wheels) to burn up the other edge of the tires.
- install a second small motorcycle battery (or my deep cycle trolling battery) as battery #2 for night fishing. Weight issue and decision. Maybe just install a #2 positive lead for quick install when I know I'll need it.

Boat seems to be holding up very well.

Maybe next year: repaint floor?

JimW wrote: - Touched up the bow area where I learned about (1) proper trailer bow eye height, (2) why a hold back strap is good to have so stop signs don't push the bow into the trailer bow roller and damage the bow.

Jim,

Again, thank you for sharing your experiences. What is a "hold back strap"?

Thanks,
Dan

Two straps running from ths bow eye, back to one of the trailer frames. Keeps the deceleration load from resting solely on the bow (point) to bow roller contact patch. This contact patch is only about 1 square inch. A one G stop would put about 1000 psi on the spot, assuming 1000 # of friction between trailer bunks and boat. I suggest this for anyone who "built up" their bow with fairing compound. If you have biaxial fillets and just a minimal fairing coat, I think the bow will survive this.

hey jason, have you thought about trying trim tabs to cure the porpoising problem? i bought a set for my gf14. unfortunately i haven't had a chance to try them cause the boats not done yet(primuing outside currently) but i i think they should help the preformance of the boat. a buddy of mine installed tabs on his 20' boat and was able to take the hydrafoil off the motor and reduce drag on the motor since they helped so much. i bought the self adjusting smart tabs for my boat for 100.00 shipped.

just thought i'd put in my $.02

boat looks great hopefully my paint job comes out as nice as yours did!

I would have put trim tabs on if they didn't cost so much. Never heard back from anyone about how well the "smart tabs" work.

Between adjusting the motor location, putting the hydrofoil on, paying closer attension to where I put stuff in the boat, and lowering my performance expectations, the boat's doing fine.

I can get up to 28 MPH on a calm day, but rarely do I want to push the flat bottom much over 22 MPH just because it becomes too rough of a ride.

Jason

Jason I will let you know how well they work. I just ordered a set of smart tabs for my GF14.

Went snorkeling this past week at Sombrero Key, just off of Marathon, FL. It's a little over half way down the keys.

Took my GF18 about 5 miles off the coast. Water was about a 1' chop near shore, increasing to 2-4' waves beyhond the reef. I'd guess we had a solid 1-2' waves on the way out and were just starting to get something like 2-4' at Sombrero Key.

Had to take it slow of course. Probably did something around 10 MPH on the way out (probably going at about 45 degrees into the waves) and 16 MPH on the way back. Pulled the kids behind in a tube. They had a blast.

All in all, not the greatest trip for the GF18, but the family's gotten used to the ride and we took it slow and easy. Kept a close eye on the forcast and clouds. Wish I had JimW's C19 for this type of run, but have to use what you've got.


I've got one picture at different zooms from the snorkel site toward Marathon and the 7 mile bridge. The lighthouse is obvious, but my wife and son are snorkeling in their blue life jackets out there (can't see them yet).



Here's a bit of a blow up. You should be able to just see my wife and son, but the next shot will give you a better idea of what you're looking for. (They're just to the right of center.)



And here's the final blow up. My wife and son are a bit blurry on the far right, but if you look cose at the horizon you can just see the 7 mile bridge on the left.