Master Marine 28' stringer question

Questions about boat repairs with our resins and fiberglass: hull patches, transoms and stringers, foam, rot etc.
doug42190
Frequent Poster
Frequent Poster
Posts: 148
Joined: Sat Mar 17, 2012 9:19 pm
Location: USA
Location: Wilmington, NC

Re: Master Marine 28' stringer question

Post by doug42190 »

Hey Larry,
Thanks for dropping by -- haven't heard from you in a while -- I am sure you have been busy with some great project -- I haven't had time to get a look at what others are doing -- just really trying to stay on top and keep the momentum going. I really appreciate your comments!
Doug

User avatar
FitzFisher
Active Poster
Active Poster
Posts: 431
Joined: Sat Jan 30, 2010 7:27 pm
Location: Riverview FL

Re: Master Marine 28' stringer question

Post by FitzFisher »

Man doug, you are really cranking out the glass work. Looking really good. Keep after it! That boat is gonna be solid if you keep laying it down like that!
You are what you is! And I is Done!

doug42190
Frequent Poster
Frequent Poster
Posts: 148
Joined: Sat Mar 17, 2012 9:19 pm
Location: USA
Location: Wilmington, NC

Re: Master Marine 28' stringer question

Post by doug42190 »

Hey Fitz -- how have you been? I keep peeking over on your site now and then -- looking good over there--just waiting to see that puppy get wet! Anything new to share?
Thanks for the comments -- I have learned a lot -- and have much to learn. I am going to continue rebuilding this boat just like I am going -- it should be rock solid from all that I can tell.
Hang in there.
Doug

doug42190
Frequent Poster
Frequent Poster
Posts: 148
Joined: Sat Mar 17, 2012 9:19 pm
Location: USA
Location: Wilmington, NC

Re: Master Marine 28' stringer question

Post by doug42190 »

Well, this past weekend was more "glass slinging." I started off by filleting the chine side of the port outer stringer, then laying three layers of 12 ounce biax tabbing -- staggered, wet on wet. Just as a side note, I have been using "brand X" epoxy for the build -- I bought a large amount and I just finished it up on this side of the stringer.
Sunday afternoon, I started the other side of that stringer (the inner side of the outer stringer).

Image

Image

The following is not a paid advertisement -- it was just my experience and I thought I would share it.

I opened my first gallon of Epoxy from Shine and co. There was a learning curve to be sure. I used the "medium hardner" from both brand X and Shine. The brand X had a longer pot life so, as it turned out, I mixed too large of a batch the first time -- not a disaster, but I did get a few voids in the first layer of tabbing. I mixed smaller batches from then on and had no more difficulty. What differences did I see? Well, I am still getting the feel for it to be sure, but I found Shine's brand really is very consistent and predictable as to how much working time you have -- and it is shorter than brand X -- somewhere between their fast and their medium hardner. However, once it kicks, Shine's formula set up much quicker and got to the "fingernail" test much quicker. I also noticed a difference in how it wet out the fabric. I cut strips off of the roll of 12 ounce biax I bought from Shine a couple of months ago to make tabbing (50" cut into 5" X 15' strips). The epoxy seems to penetrate the cloth quicker -- just eyeballing it -- no scientific data. I know I spent less time putting on the 3 layers of tabbing with Shine's than I did the day before with brand X -- I cannot say for sure why.
What was very clear to me was the speed and thoroughness that Shine's wet out 1808. I wet out the mat side -- as usual -- coated the surface to receive the 1808 -- gave it a few mintues and what a difference! The biax side seemed to absorb and change colors much quicker and with much less "dabbing" with a chip brush -- it was a noticeable difference. The end result seemed to me to be more transparent and more "clear" than brand X -- not that that was important. So, I have used almost 1 gallon of Shine's epoxy and I am getting a feel for it -- I need more time with it but I was plesantly surprised by the characteristics thus far.

Like I said, not a paid endorsement, just my experience.

I also began "redoing" the hull interior near the bow:

Image

Image

There are three "tubes" and all appear to be for added stiffness. They seem to be 3" or 4" tubes cut in half and covered with roving. The center one is where I focused. At the "open" end -- it sits about 6" below the hull level where the stringers end -- it is a steep drop off from the stringer end/bulkhead to that tube opening -- a distance of 3 or 4 feet.

Image

If you were to pull a string inside from the bottom of the transom to the bow just touching the bottom of the hull -- it would hit on the top of that tube -- and be between 2 and 6 inches from the keel the last 6 feet or so. You could almost fit a small bilge pump in that depression. The depression was filled from the bulkhead forward with stinky, smell foam -- it was about 18" to 24" thick at that spot. It went straight up from the bottom tube to the two upper tubes and then filled under the forward factory boxes -- which have now been discarded. That depression was filled in too. This picture was taken after I had removed 2/3 of the foam.

Image

I cut a piece of PVC pipe sort of shaped like a dagger to go from the open end of that tube back towards the bulkhead. I roughed it up, epoxied it in pace, filleted it and covered it with 2 layers of 12 ounce biax. That then covered/eleminated that "depression."

Image

My intention is to make that entire forward area into a large "fish hold" -- insulated with 2" of foam -- starting from the anchor locker bulkhead back about 6 feet to another bulkhead/compartment. I have cut a pattern to fit a 1/2" or 3/4" piece of plywood over the bottom for that fish hold. It is roughly 15" X 6' (it tapers to 12" near the bow). This first picture gives a rough outline for the floor of the fish box.

Image

Image

It will "float" on 4 pound foam about 4" over the top of that tube and extend/join with the rear bulkhead and be attached at each side on cleats. I will glass an area into that bottom panel (like a 8" tube open on the top inside the fish hold-- in the floor-- but sealed on the bottom) where I can put a bilge pump to empty it out -- I know no matter how well I seal the lid -- it will likely get wet inside -- either from waves/spray/rain or from melting ice with fish Image. I have considered a macerator as well.
If I can figure out how to draw on pictures, I will do so -- so that it will make more sense.

I will upload pictures tonight and hopefully this will all make sense.
Comments. suggestions, ideas welcomed.

Doug
Last edited by doug42190 on Tue Oct 23, 2012 4:49 pm, edited 5 times in total.

User avatar
Cracker Larry
* Bateau Builder - Expert *
* Bateau Builder - Expert *
Posts: 22491
Joined: Fri Mar 11, 2005 3:39 pm
Location: Savannah, GA

Re: Master Marine 28' stringer question

Post by Cracker Larry »

Very clean looking work, Doug. Real nice 8)
So, I have used almost 1 gallon of Shine's epoxy and I am getting a feel for it -- I need more time with it but I was plesantly surprised by the characteristics thus far.
I've used over 100 gallons of it and I like it too. Can't beat it for the price.
Completed GF12 X 2, GF16, OD18, FS18, GF5, GF18, CL6
"Ships are the nearest things to dreams that hands have ever made." -Robert N. Rose

doug42190
Frequent Poster
Frequent Poster
Posts: 148
Joined: Sat Mar 17, 2012 9:19 pm
Location: USA
Location: Wilmington, NC

Re: Master Marine 28' stringer question

Post by doug42190 »

Well, here is my latest update. Last weekend I got more time to work on Isabel (my boat -- named after hurricane Isabel of 2003 -- Isabel dropped a massive pine tree on the hull in my backyard while living in Richmond, Va. Fair amount of damage but I found a great fiberglass guy and $2500.00 later, good as new.).
So the next phase is the starboard side of the hull, replacing the roving I took out a few months ago. I had removed 1/4" of roving and ground the hull and have been plugging away with replacing the strength and stiffness I removed with that roving. I am going back with alternating layers of 1708 and 1808 -- two each with epoxy.
So I started this phase by vacuuming, wiping the hull section down with acetone, followed by a light grinding/sanding, then vacuum, and another acetone wipe. The sides of the hull were smoothed some (roving was very pronounced and rough) for about 22"-24" up from the chine. The chine/hull side joint was ground out some so that I could lay a fillet in there and a layer of tape to make the transition from bilge up over the chine and up the sides with the 1708 and 1808.

Image

Image

Image

Then I laid the fillet on the chine side, followed by the fillet on the stringer side

Image

Image

Then the chine side got one layer of 12 ounce biax tape and the stringer side got three.

Image

Image

Image

Then another quick grind/sand of all of the drips, etc, vacuum, acetone wipe and then I laid out the lines for me to follow for applying the overlapping layer of 1708 and 1808. The lowest line is 6" from the chine and the rest are each 4" higher -- total from the chine is 18".

Image

Image

I only got 2/3 of the first layer and about 1/2 of the second layer before I lost the sunlight and the temperature started to drop -- and I was sore from all the bending over, crawling around on my knees, etc. I didn't get any pictures of what I did get done.
So any thoughts, concerns, ideas, or comments are encouraged and welcomed.
Thanks for dropping by.
Doug
Last edited by doug42190 on Thu Nov 08, 2012 12:38 pm, edited 1 time in total.

User avatar
tech_support
Very Active Poster
Very Active Poster
Posts: 12318
Joined: Wed Dec 31, 1969 7:00 pm
Location: Vero Beach, FL
Contact:

Re: Master Marine 28' stringer question

Post by tech_support »

If the idea was only to rebuild thickness on the bottom, the you do not need to take the overlaps that high up the sides (6" is all you need). Also do not need to put tape in the chine corners - plenty of glass there with the overlap of bottom glass.

doug42190
Frequent Poster
Frequent Poster
Posts: 148
Joined: Sat Mar 17, 2012 9:19 pm
Location: USA
Location: Wilmington, NC

Re: Master Marine 28' stringer question

Post by doug42190 »

Shine,
Thank you for the feedback. My reasoning for taking it up the sides is to help offset my removal of/doing away with the liner -- not really much to do with removing the roving from the bilge/hull bottom surface. I see now that I did not make that clear at all. I am guessing that I may also need to add stiffners of some sort (hollow tubes overlayed with fiberglass) but I was trying to replace some of the stiffness and strength/support I will lose from doing away with the liner. I think that attaching the sole to the hull sides will help as will the addition of floor frames every three feet in the bilge and 4 total bulkheads -- but my reasoning was to help with stiffness. Maybe it is overkill or not as useful as I had hoped. I do not want to come off as arguing but simply trying to learn a little more by asking questions.
The fillet and tape on the area from the chine up the side came about because the angle was so sharp that the fiberglass couldn't make the bend -- I did this out of desperation. The angle, just a guess, is about 75 or 80 degrees -- I just couldn't get the glass to stay in that tight angle. I do hope these approaches are not harming the final outcome, although I am aware of how much cheaper this project could have been and how much lighter this boat would be if I had followed more what you are suggesting. I guess since I did this on the port side already, I should go ahead and do the same on the starboard -- or is that a mistake?

ImageLastly, a question about foam sheets -- even the stuff you can buy in the box stores. I have some pink 3/4" stuff that is not bothered by epoxy and seems to hang on pretty well. Since it is so light, can this be used for weight savings -- I am thinking about floor frames, bulkheads, "false transom walls," hatches, ice chests, etc. if covered with epoxy and biax? Or am I asking for trouble and should stick with plywood for the more structural stuff (floor frames, bulkheads, etc)? Image
Thanks and I appreciate your comments a lot.
Doug

User avatar
tech_support
Very Active Poster
Very Active Poster
Posts: 12318
Joined: Wed Dec 31, 1969 7:00 pm
Location: Vero Beach, FL
Contact:

Re: Master Marine 28' stringer question

Post by tech_support »

My reasoning for taking it up the sides is to help offset my removal of/doing away with the liner -- not really much to do with removing the roving from the bilge/hull bottom surface.
In that case, just glass in a half PVC pipe. Cover it with one layer of 1708. Use a light weight PVC pipe (irrigation grade), this will give a lot more stiffness, weigh less, and take less time than adding all that glass.
Maybe it is overkill or not as useful as I had hoped. I do not want to come off as arguing but simply trying to learn a little more by asking questions.


The stiffener and any frames you use above the sole will stiffen up the sides
The fillet and tape on the area from the chine up the side came about because the angle was so sharp that the fiberglass couldn't make the bend -- I did this out of desperation. The angle, just a guess, is about 75 or 80 degrees -- I just couldn't get the glass to stay in that tight angle.
got it, no problem there
I should go ahead and do the same on the starboard -- or is that a mistake?
If you have only done a couple layers of the 1708 up the sides, then just stop now and glass in your longitudinal stiffener (PVC pipe or similar). Its not going to matter if you have a few pounds of extra glass on the one side.
I have some pink 3/4" stuff that is not bothered by epoxy and seems to hang on pretty well. Since it is so light, can this be used for weight savings -- I am thinking about floor frames, bulkheads, "false transom walls," hatches, ice chests, etc. if covered with epoxy and biax?
it will not work, that foam does not have the sheer or peel strength needed for a composite sandwich. It will delaminate. It can be used for forms (when the part is getting 100% of its strength from the glass = thick) but thats not the same thing as a core.

You can save some weight by using foam core and thin skins, but the core needs to be a real structural core.

doug42190
Frequent Poster
Frequent Poster
Posts: 148
Joined: Sat Mar 17, 2012 9:19 pm
Location: USA
Location: Wilmington, NC

Re: Master Marine 28' stringer question

Post by doug42190 »

WOW! Now that is good information. I will not take the last two layers up the sides but just to the chine so that I return the 1/4" I took out. That will save me a mountain of work, glass, and epoxy!!!
The PVC pipe for the stiffener -- 3" cut in half? 4" cut in half? Should it run from basically the transom all the way to the bow (or pretty close to it)? Epoxy glue it in place, then fillet -- should I tape it too before the 1708? And you mentioned one layer -- is one really enough or were you using a figure of speech -- because one is great with me if that's the right thing to do -- I don't mind more if it is needed. Lastly, ideally, where should it be in reference to the sole height and the top of the cap? The top of the sole should be roughly 1" above the bottom black line on this picture. The top line is 12" above the lowest black line (roughly 11" above the top of the sole). Can you give me some idea where you would put the stiffener? I would really appreciate it.

Image

This really gets me excited because it means I can move forward much faster this way -- basically saving me MANY hours of work and a great deal of money. Image Image
Thank you very much!

Doug

Post Reply

Who is online

Users browsing this forum: No registered users and 5 guests