Boat Builder Central - Builder Forums

Posted: **Thu Jan 13, 2022 1:40 am**

Hey folks, just getting started assembling things to kick off this build. Using the CNC kit and SilverTip epoxy kit. The boat will be used to fish the very shallow Texas coastal marshes and flats. New to boat building and fiberglass construction in general so will probably have lots of questions moving forward. Love all the similar threads on current and past builds and have learned a ton reading through them. Some really nice boats y'all have built out there!

Below are some pics of the updated assembly. Been working on and off for about 5 days now and have the strong back assembled, stringers and transom sanded and 1 layer of epoxy applied before i glue them together. A couple questions below if anyone has any advice. Also, if there is anything you feel a first time boat builder and rookie fiberglasser should know, please feel free to chime in! Thanks again and will try to keep this as up to date as possible!

1. i noticed some "divots" in the CNC cut transom pieces near the edges. Should i just fill them in with extra epoxy when i glue the transom pieces together? or use some other product before that? its a few small indentations near the edges where the very top ply of wood chipped back a bit.

2. i am planning to use the Gel Magic to glue the transom and stringers together. Any other applications y'all recommend for this?

3. For the tunnel, when do you recommend i cut out the tunnel opening in the transom? after i glue all 3 pieces together or before and then glue after?

Posted: **Thu Jan 13, 2022 8:10 am**

Hey man I’m new to it too! I’m building the same boat up here in NC with a tunnel. Pretty sure me and you will be the only ones that have built one with a tunnel. We’ll have to collaborate!

I think the only advise I can give you is to make sure to sand those panels you precoated before applying anymore resin or you might get a weak bond. I also might have some tips for you when you get to that tunnel.

~Ryan

Posted: **Thu Jan 13, 2022 9:57 am**

When you laminate the transom and stringers, fit them together dry first and drill holes for nails or dowels . . something to lock them into place so when you've got them wet with epoxy they don't slip and slide out of position. Also, some guys like to drill a vent hole or two in the middle area of the top layer of the transom assembly so they can see glue squeeze out and confirm they've got enough glue and weight to do the job.
As to the chips on the edges, a smear of glue will fill those right up. Keep a note pad at hand while you're building and make notes of any small needs for filler or glue so that you can catch the little things when you've got a batch mixed up for a bigger job.

Posted: **Thu Jan 13, 2022 11:14 am**

Thanks Both!

Ryan - will def get ahold of you when i start doing the tunnel - Question, did you cut the tunnel out of the transom before you glued all the pieces together? or after you had formed the 3 layer transom?

Pee Wee -
- So do you recommend drilling small holes through all 3 transom layers and fitting either a nail or small dowel rod while the pieces cure? Once they cure, do you pull it out and fill
in with epoxy resin? I'm using the Gel Magic, will i still need the vent hole for this product since its a little thicker than normal resin?
- And noted on the vent hole, very helpful, is that only for the top piece or for all three in same spot?

Posted: **Thu Jan 13, 2022 2:37 pm**

I cut the tunnel notch in one transom piece and used it as a template. You could cut all three together if you wanted. Not sure what kind of tools you’re using. I didn’t have the cnc kit, sometimes I wish I would’ve bought it.

Posted: **Thu Jan 13, 2022 2:38 pm**

What are your plans for your boat? Tiller, remote steer? What size motor. I’ve changed my mind about 5 times in the last month…

Posted: **Thu Jan 13, 2022 3:26 pm**

Sounds good! i am planning to cut the tunnel notch in the transom after it cures and also after i have assembled the hull, prior to laminating.

And i plan to do very small center console with a 50hp Tohatsu or Yamaha, assuming weight isn't too much of an issue. My goal for this boat is more shallow water performance than top speed. I need to get up in close to nothing as these marshes over here are super skinny.

Posted: **Thu Jan 13, 2022 3:32 pm**

Same here. I’m looking for a 40-50 motor, they’re hard to find. Lately I’ve been looking for a donor boat. I’m going to do a small console as well.

Posted: **Thu Jan 13, 2022 5:22 pm**

are you trying to find a used motor? i was looking and probably going to get a new one if i don't find anything nice that is used

Posted: **Thu Jan 13, 2022 7:05 pm**

Yeah man NC is tapped out. I’ve been looking in Florida too. I may have to go there to find one. The good thing about a repurposed boat, you could probably rob some other stuff off it.

Posted: **Fri Jan 14, 2022 9:50 am**

GrantL wrote: ↑Thu Jan 13, 2022 11:14 am Pee Wee -
- So do you recommend drilling small holes through all 3 transom layers and fitting either a nail or small dowel rod while the pieces cure?
It doesn't really matter which way you do it, before applying glue you could nail a couple finish nails from the top into the one below, fit the nails back into the same holes once glue is on. Pull them once the glue has set. Or you can fit dowels extending from the bottom layer through the next layer. If you glue them in, just leave them. If you didn't glue them in . . . just leave them!
Once they cure, do you pull it out and fill in with epoxy resin? I'm using the Gel Magic, will i still need the vent hole for this product since its a little thicker than normal resin? You don't have to use a vent hole, but it would be just as useful for Gel Magic as thickened epoxy. No need to go crazy with them, but a couple will give you peace of mind that you've got enough weight on there.
- And noted on the vent hole, very helpful, is that only for the top piece or for all three in same spot?
The vent hole(s) would be in whatever is the top piece you're gluing, I wouldn't recommend doing all three at once.

Posted: **Fri Jan 14, 2022 12:02 pm**

pee wee wrote: ↑Fri Jan 14, 2022 9:50 am
GrantL wrote: ↑Thu Jan 13, 2022 11:14 am Pee Wee -
- So do you recommend drilling small holes through all 3 transom layers and fitting either a nail or small dowel rod while the pieces cure?
It doesn't really matter which way you do it, before applying glue you could nail a couple finish nails from the top into the one below, fit the nails back into the same holes once glue is on. Pull them once the glue has set. Or you can fit dowels extending from the bottom layer through the next layer. If you glue them in, just leave them. If you didn't glue them in . . . just leave them!
Once they cure, do you pull it out and fill in with epoxy resin? I'm using the Gel Magic, will i still need the vent hole for this product since its a little thicker than normal resin? You don't have to use a vent hole, but it would be just as useful for Gel Magic as thickened epoxy. No need to go crazy with them, but a couple will give you peace of mind that you've got enough weight on there.
- And noted on the vent hole, very helpful, is that only for the top piece or for all three in same spot?
The vent hole(s) would be in whatever is the top piece you're gluing, I wouldn't recommend doing all three at once.

thanks Pee wee for your comments on the transom. What is the issue trying
to do all 3 pieces at once? just too much opportunity to slide around?

and for the vent holes, do you do a couple tiny ones? like 1/8 inch? or
less? and are they spaced randomly throughout the top piece?

Posted: **Fri Jan 14, 2022 12:38 pm**

There's nothing technically wrong with doing both at once, but that would be a handful. I'd at least let the first layer set up and then follow with the second glue-up. The advantage with doing one layer at a time would be the opportunity to use the vent holes and observe that each layer has provided ooze out, while if you've got three layers you won't know what's doing what. Further, it will take some time to do, what with neat coating both sides, then use a notched trowel to spread out your glue, then assemble and if you're doing all layers then you'd have to get the next ones done before the first layer has begun to thicken . . . no, I'd say don't try to do it all at once.

I'm not sure how big your transom will be, but if you have two or three holes scattered over the central area that ought to suffice. A bigger boat might benefit from more holes. I don't know what the ideal size would be, but one eighth sounds a bit small; the idea is that when you see glue (Gel Magic) oozing up through the holes you can assume your panels are tight enough together for an even and strong lay up. If you don't see any glue squeezing out the holes, then add more weights because maybe you've got voids. You don't want to squeeze all the glue out, but some glue squeezing out tells you it's probably all solid. I don't know what you've got for weight, but try to spread them out evenly.

Posted: **Fri Jan 14, 2022 1:14 pm**

pee wee wrote: ↑Fri Jan 14, 2022 12:38 pm There's nothing technically wrong with doing both at once, but that would be a handful. I'd at least let the first layer set up and then follow with the second glue-up. The advantage with doing one layer at a time would be the opportunity to use the vent holes and observe that each layer has provided ooze out, while if you've got three layers you won't know what's doing what. Further, it will take some time to do, what with neat coating both sides, then use a notched trowel to spread out your glue, then assemble and if you're doing all layers then you'd have to get the next ones done before the first layer has begun to thicken . . . no, I'd say don't try to do it all at once.

I'm not sure how big your transom will be, but if you have two or three holes scattered over the central area that ought to suffice. A bigger boat might benefit from more holes. I don't know what the ideal size would be, but one eighth sounds a bit small; the idea is that when you see glue (Gel Magic) oozing up through the holes you can assume your panels are tight enough together for an even and strong lay up. If you don't see any glue squeezing out the holes, then add more weights because maybe you've got voids. You don't want to squeeze all the glue out, but some glue squeezing out tells you it's probably all solid. I don't know what you've got for weight, but try to spread them out evenly.

Thank you sir! will do one at a time for now. using some drywall screw to fasten pieces together and will drill the vent holes.

I saw you mentioned a ridged trowel to spread glue.... i was using a dense foam roller before hand. do you think it will work for this transom or is a notched trowel the way to go?

Assuming the glue doesn't need to be layed on too thick but a needs to have a little thickness to it to fill in any uneven voids? thanks!

Posted: **Fri Jan 14, 2022 3:11 pm**

I don't like the drywall screw approach because while they pull, they might also hold the panels apart. I like weights better because they keep on working after you step away. The goal is to get an even coat of glue between the panels, I've heard people say a millimeter thick, but I'd think less than that. I guess rollers would work for spreading glue, too! As long as you get enough on there and it's spread around evenly and there's no big air pockets you're good to go.

Posted: **Fri Jan 14, 2022 3:17 pm**

I really like using wood dowels to line things up. Makes it easy to keep things from sliding around. Taper the tops so it is easy to get them lined up.

Posted: **Sat Jan 15, 2022 3:32 am**

thanks everyone for the tips on prepping the transom pieces. I ended up using the dowel approach and was very pleased with it. I glued two of the transom pieces together tonight with Gel Magic and will let sit overnight.

Few questions for those familiar with Gel Magic or just transom gluing in general. I used 12oz total of Gel Magic (resin + hardener) to glue two of the transom pieces together.
- Do you think that was enough? i was surprised how much the transom took
- I only applied the gel magic glue to one side of the transom pieces and then joined the other piece together with the side that had the gel magic on it. I did this
because i was out of gel magic and didn't know if i had enough time to make another batch before it started curing. Do you think applying glue to only one side before joining
the two pieces is a cause for concern?

I used quite a bit of weight on the pieces after they were set but i did NOT have any glue seep out of the vent holes. It got me nervous i might not have used enough? Anyways, when applied with a trowel, i tried my best to evenly coat the transom piece, but now worried, i didn't use enough. Any thoughts or advice to test it out after curing or just opinions on how much you feel is enough or if i should be concerned? Thanks again for all the help and words of wisdom!

Posted: **Sat Jan 15, 2022 10:05 am**

If you didn't have any squeeze out around the sides or out the holes, you didn't use enough glue. It's possible you used the exact right amount that filled everything almost to the point of squeeze out, but how can you be sure? Did you neat coat both pieces with epoxy before spreading the Gel Magic? If you want to know for sure how well it's done, take a hole saw and cut a sample from the transom. Post a photo here and let the guys see it. After looking at it you will either start over (that would suck, but it's better than forging ahead with a weak part) or glue the piece back in and keep going, with the assurance it's solid.

Posted: **Sat Jan 15, 2022 1:47 pm**

Is that all the weight you used with none on the corners? If so you needed more weight on the two corners that have no weight on them. What type of trowel did you use, a toothed one if so then you did not get enough to go both ways in opposite directions on each board. If you used a solid straaight edge trowel did you leave any low spots that would not provide a good bond. Then do as peewee said and make a 5 hole saw cut outs 1 from each qarter and 1 from the center. If there is one thing you don't want to fail it's the transom.

Tom

Posted: **Sat Jan 15, 2022 8:07 pm**

Thanks both for your insight. I decided to reset and re-cut the transom and glue it again. i found some more gaps near the edges in between the 2 pieces (could slide a piece of paper up to 1 inch in between the pieces). Coupled with what Tom and Pee Wee mentioned, i decided to buy a sheet of Okume plywood, re-cut and re-glue.

3 questions-

- do you lay glue in opposite (90 degree) directions on the 2 faces you're gluing?

- if 12oz of total glue wasn't enough is there a good rule of thumb for oz/area of wood? (transom only)

- any better recomendations on ways to set the pieces once glued and weight down corners better? other than just using more random weights around the piec?

Lastly, and most important, i bought a new sheet of 4x8 marine okume (9mm), it looks like the individual plys are different thickness paterns than the sheets sent in the CNC kit. is that an issue as long as the total width is the same? (which it is)...... see pic below, bottom is CNC kit, top is sheet bought today from hardware store

Posted: **Sat Jan 15, 2022 10:43 pm**

pee wee wrote: ↑Sat Jan 15, 2022 10:05 am Did you neat coat both pieces with epoxy before spreading the Gel Magic?

FYI you don't need to do that for gel magic. From the TDS:

NOTE: GelMagic may be used directly on new wood without pre-coating with an epoxy coating or sealer. If substrates are
pre-coated, sand any cured material in the bonding area prior to using GelMagic.

Posted: **Sun Jan 16, 2022 11:06 am**

joe2700 wrote: ↑Sat Jan 15, 2022 10:43 pm
pee wee wrote: ↑Sat Jan 15, 2022 10:05 am Did you neat coat both pieces with epoxy before spreading the Gel Magic?
FYI you don't need to do that for gel magic. From the TDS:

NOTE: GelMagic may be used directly on new wood without pre-coating with an epoxy coating or sealer. If substrates are
pre-coated, sand any cured material in the bonding area prior to using GelMagic.

I learned something today, thanks!

Here's a discussion on gluing up transom pieces that may help. By the way, Cracker Larry was an expert builder who we all benefited tremendously from.
viewtopic.php?t=60364&start=20

You will notice that Larry likes to glue all the panels up at once, like you mentioned (but aren't you glad you didn't mess up all the panels in one go?). I find the search features of the forum to be a bit difficult to use, but there is a lot of information here if you can dig it out.

As to the differing ply thickness on what you bought at the hardware store, it should be okay for a flat panel like the transom, but isn't great for bent panels.

Posted: **Sun Jan 16, 2022 2:00 pm**

Grant are the number of layers in your new Okume the same as the ones you got in your CNC kit, and can you show us the Okume label so we can make sure it is good for you.

Now for applying the Gel Coat the best way is a toothed trowel going in opposite directions on each board. Here is one sold in the store here but you can buy similar ones at any hardware or home depot/lowes tile section. https://www.boatbuildercentral.com/prod ... st-system/ Use the tall teeth. Do not worry to much about time Gel Magic has a 30 minute work time till it gels at 77F. The other thing is to make sure your weight is evenly distributed.

Well good luck to you.

Tom

Posted: **Sun Jan 16, 2022 5:08 pm**

Glueup.

Precoat the join with epoxy 2oz per yard both sides. Allow it to gel for one hour. Then make thickened epoxy.

Use 1/16" vee trowel.

Trowel both sides of the bond.

It takes a lot of thickened epoxy. A lot.

Use about 2.2 times the volume of epoxy for the amount of fumed silica. Sorry no data on wood flour; guessing close-ish. The stuff is ready when it won't sag or flow. After you get it stiff enough; lay it out flat on a board and it won't gel too fast.

It takes a long time to apply, but don't worry about direction; just get it all coated. Do not do it in hot sun or hot weather. 70F is your friend.

The perfect bond dimension is 40 microns or one millimeter.

The ideal bond pressure is about 4 psi which is basically unattainable with weights. But 2 psi is plenty. Avoid unbalanced weights. Use timbers or wide boards to disburse loads. Concrete blocks or water jugs or other heavy weights.

A 1.5 foot by 6 foot glueup is 9 square feet or 1300 square inches; 2 psi is 2600 pounds, but avoid driving a car on it. That will point load and squeeze out the resin.

You won't get to 2600 pounds, but you need a LOT of weight. A 1/16 vee both sides is 1/8" and 3mm and you are trying to push it down to 1mm.

Posted: **Tue Jan 18, 2022 5:44 pm**

Thanks everyone for the input. Had family in town last weekend so got delayed on my next plan to re-glue the transom.

Fallguy - thanks for your detailed input on gluing. I am using Gel Magic epoxy but assuming the procedure (minus mixing of silica) is about the same. Just so I understand, you are saying about 1 mm on each bonding surface is a good way to measure the proper amount of glue to apply?

Do prefer to use weights on flat ground or combination of weights and clamps on elevated surface to let cure?

Posted: **Tue Jan 18, 2022 7:42 pm**

You don't need to precoat with gel.magic. per their doc. Do your own research but that's my understanding. If you do precoat, make sure it's compatible(silvertip).

Posted: **Tue Jan 18, 2022 8:01 pm**

Find the flattest surface you can find.

1mm final is the ideal bond

This is achievable with 1/16" vee trowel each side and a lot of pressure from vac bag or weights. You will want several hundred pounds balanced on timbers.

Both sides get resin. If you are using gel magic; you may not have enough to do both sides. It takes a lot of resin. A lot for proper bonding. You should be prepared to run out of gel magic and be ready to mix homemade with either silica or wood flour (No sawdust!).. about 2.2 to 1 (fillers to mixed epoxy)

Posted: **Thu Jan 27, 2022 5:35 pm**

Thanks everyone for the continued insight and advice! Ended up re-cutting and re-gluing the transom as instructed and it was night and day better. The one item that made the most difference was a v-notched trowel. I used a 1/8'' but 1 /16'' should work as well. Having the glue spread on evenly really does make a huge difference in ensure there are no gaps in the bond.

I also spent some time glueing the stringers up. used same method of laying a thin pre-layer of epoxy and sanding down. Then went back over with gel magic on both bonding surfaces using a 1/8 v-trowel. slapped the pieces together and used clamps at various intervals to hold together while it set. I was curious as i feel i needed more clamps than what i used. I only had good glue ooze out of the seam in the areas where the clamps were applied. Some other areas, you could tell weren't squeezed together as tought, however i know the epoxy bonded between teh two pieces, there is just a couple slight/tiny gaps in between the pieces along the edge of the stringers. Assuming that is ok? was thinking of mixing up some thin epoxy and laying/pouring in a coat over the seam of the two pieces along the entire edge, to hopefully fill in any tiny gaps and seal the seam from any possible moisture intrusion.

I spent some time looking at how others clamped the stringers and i would say i was about average (slightly below) on the number of clamps/spacing used. Any more thoughts on this before i move on to framing everything up?

Posted: **Thu Jan 27, 2022 9:43 pm**

The best way to clamp is flat surface; lotsa weight. Local clamps will result in less than flat surfaces as clamp pressures are not even...

Not enough c clamps? You can use a board woth any warpage in the middle and to the work and use fewer clamps,

But clamps and a flat surface are needed.

When I use 1/8" trowel; I one side the bond and neat coat the other side.

Timbers and weights or vac are my preferreds. My vac pumps need repair or a kit now.

Posted: **Thu Jan 27, 2022 10:07 pm**

Here are some pics of the gaps I was discussing. Do you think those are ok or if I poured some epoxy into the gaps to seal?

If this is something I need to re-do, I’m totally fine with it as I already re-cut and glued transom hahha. But at same time if that gap is maneagable for the stringers then I’ll leave it. Any advice is appreciated!

Posted: **Thu Jan 27, 2022 10:32 pm**

Fill em with thickened resin. Final gap is best at 1 millimeter.

Posted: **Fri Jan 28, 2022 12:33 am**

I would think the stringers are ok. Maybe needed a little more glue or more clamp pressure or both. The gap at the butt joint is short on glue and needs to be filled in. While things may not be perfect this method of building is so strong I am guessing you are good.

Posted: **Fri Jan 28, 2022 11:25 am**

thanks both for your feedback! I was using Gel Magic for the glue so will mix up a little bit more and fill in all the gaps on the stringers.

Next up the frames.... For that, i was going to set the transom and Frame A and and then work towards the middle, is that a good plan?

Posted: **Fri Jan 28, 2022 1:32 pm**

I am pretty sure the plans will tell you the best way to move forward.

Posted: **Tue Feb 01, 2022 8:05 pm**

Glued up second and third pieces of transom and filled in gaps in stringers as discussed with gel magic. Will start assembling the frames on jig tomorrow as well as glueing together puzzle joints on panels.

Question - can I use the gel magic for the puzzle joints or stick to a thickened epoxy with wood flour? Or some other compound y’all recommend?

Posted: **Tue Feb 01, 2022 11:33 pm**

GrantL wrote: ↑Tue Feb 01, 2022 8:05 pm Glued up second and third pieces of transom and filled in gaps in stringers as discussed with gel magic. Will start assembling the frames on jig tomorrow as well as glueing together puzzle joints on panels.

Question - can I use the gel magic for the puzzle joints or stick to a thickened epoxy with wood flour? Or some other compound y’all recommend?

You can use gel magic pretty much anywhere you need thickened epoxy as an adhesive, so don't see any reason not to use it for the puzzle joints. I see lots of people here recommending ways to avoid using gel magic since it's more expensive than mixing your own, but if you aren't trying to minimize your use of it then it's a great tool for the job.

Posted: **Wed Feb 02, 2022 10:11 am**

All those clamps are really not needed.

Just glue those up on the floor with a locating pin so they don't slide much.

The way you are gluing in the air like that is going to result in bends or broken feets.

Lose the clamps next time. Put all the weight on timbers on 1/3rds of the piece and make sure the pieces have a pin through them in 3-4 places.

Looks like about 400 pounds on it and that is good.

Otherwise, carry on.

Posted: **Wed Feb 23, 2022 3:05 am**

Hey folks, been wrapped up with work and finally caught a break to knock out a few more items.

Spent some time finishing the transom and stringers. assembled the molds tonight on the jig and placed the stringers in the notches. I spent quite a bit of time leveling out the mold frames and ensuring they were straight and true running down the jig. I did this by measuring per the instructions (between each mold) and then running a string inside the notches from from to back to ensure the molds were straight (left to right). After ensuring everything was true, i placed stringers in notches and called it. A few questions below...

Only major issue i had was that the stringers in most molds were not flush and usually 1/8-1/2 inch above the edge of mold. I tried using a soft mallet to force the stringers down further but no luck. Any suggestions? should i just cut notches deeper until the stringers lay flush with mold nothches? see pics below for example.

Any advice on how to brace the transom to the stringers when mounting? just a lot of clamps?

Just fyi, the particle board for frames C and D are too thick for the pre-cut notches in stringers. I had to use a dremel to widen out those notches to get them to fit down into mold notch

Posted: **Wed Feb 23, 2022 8:09 am**

If the stringers are too wide; they won't fit. If the notches are too shallow they won't fit. If a station mould is too high they won't fit. If the stations are not leveled to the waterline they may not fit.

Lotsa variables.

Most likely a laminated stringer is dimensionally incorrect in some way. Ideally, you determine a way to make the stringers right because if they are uneven; that variation of 1/8 -- 1/2 can translate to the sole if you jist notch deeper.

Posted: **Wed Feb 23, 2022 9:05 am**

One approach is to cut those notches a little bit over depth and then shim them back to level. You won't rely on those notches being the exact right depth when you assembly the boat, you'll be spacing the stringers and frames off the bottom and spacing the stringers and frames from each other to ensure you have gaps everywhere. This ain't shaker furniture.

I supported my transom with a "dead man" to take the weight of the stringers, just a 2X4 clamped on that ran to the floor. I screwed some 2X2 to the back edge of the stringers and then screwed the transom to the 2X2. This worked well for me and required no clamps.

The transom is actually going to be attached to the sides and bottom at this stage so it's position and fit is a little more important than the stringers and frames which are only acting as molds at this point. As long as your panels are fair when they are stitched, the molds are doing their job.

One thing I messed up was over-tightening my side-to-bottom stitches, causing the side panels to flare at the sheer, resulting in a lot of extra effort to get them into proper shape after I flipped. Beware large gaps between your molds and side panels at the sheer and correct before glassing.

That's my .02, worth every penny!

Posted: **Wed Feb 23, 2022 11:55 am**

VT_Jeff wrote: ↑Wed Feb 23, 2022 9:05 am One approach is to cut those notches a little bit over depth and then shim them back to level. You won't rely on those notches being the exact right depth when you assembly the boat, you'll be spacing the stringers and frames off the bottom and spacing the stringers and frames from each other to ensure you have gaps everywhere. This ain't shaker furniture.

I supported my transom with a "dead man" to take the weight of the stringers, just a 2X4 clamped on that ran to the floor. I screwed some 2X2 to the back edge of the stringers and then screwed the transom to the 2X2. This worked well for me and required no clamps.

The transom is actually going to be attached to the sides and bottom at this stage so it's position and fit is a little more important than the stringers and frames which are only acting as molds at this point. As long as your panels are fair when they are stitched, the molds are doing their job.

One thing I messed up was over-tightening my side-to-bottom stitches, causing the side panels to flare at the sheer, resulting in a lot of extra effort to get them into proper shape after I flipped. Beware large gaps between your molds and side panels at the sheer and correct before glassing.

That's my .02, worth every penny!

Great post and I learned something, too.

Posted: **Sat Mar 19, 2022 2:33 pm**

Thanks everyone again for the great info and help along the way. I have the boat framed up now and fixed to start laying and stitching the panels.

1 questions on the puzzle joints - can you wet with regular epoxy on the grain ends of the joint and then after it kicks it, apply some EZ fillet to the joint? I don't have any wood flour so my only options are either all epoxy resin or a combination of epoxy/resin and EZ fillet to join the puzzle joints. Thanks!!

Posted: **Sat Mar 19, 2022 5:29 pm**

You cannot bond with all epoxy because you will end up with a bondline flaw. Epoxy bondline is not super strong and subject to limits. Then if you have a void; it is much worse as a weakpoint of up to zero ultimate strength may exist.

Use the ez fillet or some epoxy putty; not sawdust. And after precoating..

A small correction. All epoxy bonds can work if you can be certain no bondline flaw exists. The puzzle joint is also far more forgiving than an end to end bond.. Foam core is often end to end bonded with epoxy only, for example, usually under vacuum.

Posted: **Sat Mar 19, 2022 5:51 pm**

Ok thanks!

So do you recommend to wet first with epoxy and then EZ fillet over or just use EZ Fillet only straight on the wood/joint?

Posted: **Sat Mar 19, 2022 6:16 pm**

GrantL wrote: ↑Sat Mar 19, 2022 5:51 pm Ok thanks!

So do you recommend to wet first with epoxy and then EZ fillet over or just use EZ Fillet only straight on the wood/joint?

Prewet until tacky..takes an hour. Then use putty.

Posted: **Mon Mar 21, 2022 12:54 am**

Thanks, will start doing the puzzle joints this week.

1 more question - there was a small area on the edge of one piece of the plywood (puzzle joint) below that came de-laminated. It looks like some oil or substance was dripped on it and it peeled back at least of of the ply layers. Do you think this is fixable by just sanding out the affected area and filling in with EZ fillet? Or recommend using something else? Or should I get a new CNC piece cut and sent? Thanks and pics below.

Posted: **Mon Mar 21, 2022 6:04 am**

Oil is very bad for epoxy work.

If you received it that way, I'd give them a call.

If you did it and don't want it to cost you hundreds of dollars, then you'd need to remove the oil soaked section with a utility knife and sand it out and acetone wash and piece it back in with fiberglass and some thickened resin on the edges which would be tapered to the good wood. If you go this route, measure the cutaway thickness. A piece of db1700 is about 0.035". But a lot of work to repair..unfortunately.. make the glass repair a bit thinner than the original and use some fairing compound prior to your glasswork to make it all fair.. If you do a repair, I can offer you more details if you are confused.

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