Fiberglass tri hull rebuild

[Tomer9764]

I started a thread a while back about my plans for this rebuild.
Im using west system epoxy, mat and 18oz woven for thickening the hull back up
There were some really lousy repairs from the last person who did them. The transom had been patched twice, i found three different transoms in there. Ugg. With all the flexing there were stress cracks so i had to grind deep.

 

[Tomer9764]

Re: Fiberglass tri hull rebuild

I hit the corners with mat and epoxy. The splash well drain is being relocated. a prior repair that I had to grind out and replace, filled back in. prepped. . One layer of mat and 18oz woven, sadly a lot of epoxy....but its strong as hell! I plan on doing this to the rest of the hull just along the bottom extending about 8" beyond where the edges of the floor will be and up at an angle in the back corners to tie into the transom skin. I want to stick with the 18oz for sure but I know the mat sucks up resin. Any thoughts?

 

[gm280]

Re: Fiberglass tri hull rebuild

Interesting start. I'm sure others that have gone through this a few times will chime in here shortly. I'll be looking in on your progress as you post more results and pictures. I do like the rims on your trailer too... Also, welcome to iboats. Another project to watch as it moves along to a finished boat... Good luck!

 

[Woodonglass]

Re: Fiberglass tri hull rebuild

Uhmmm, typically you don't use mat (CSM) with epoxy. Epoxy does not contain Styrene to break down the fibers in mat. The loose fiber make up of mat really offers no significant strength to the mix but as you have found it does soak up the resin. You'd be much better off using a biaxial woven fabric. It's much stronger an will use much less resin and easier to work with than the woven roving.

 

[Tomer9764]

Re: Fiberglass tri hull rebuild

Thanks for the response. What biaxial would you recommend? I need to do the whole bottom of the hull like I did with the transom skin. She's pretty beat up. When the inside structure is done I want to flip it over and do the repairs from the outside without having to grind through the hull.

 

[Woodonglass]

Re: Fiberglass tri hull rebuild

If all you're wanting to do is reinforce the hull a bit, I'd use some 7.5 oz E-Glass like this...Fiberglass Cloth

 

[Tomer9764]

Re: Fiberglass tri hull rebuild

I've ordered from them before, they ship quick. I like the looks of the 10oz eglass. The other thing is by the time I get to the stringers I will have to scuff it up with 40 grit in order to glass them in.

 

[Woodonglass]

Re: Fiberglass tri hull rebuild

Epoxy is Very Strong just by itself. 10 oz cloth/fabric is used by the Off Shore Racing boys in their builds. IMHO it's a bit overkill for your hull but you can use it if you want.

 

[Tomer9764]

Re: Fiberglass tri hull rebuild

Ok guys. The grinding is done. I have had to grind deep into the chine, strake, and keel due to **** poor manufacturing. The stringers lay in the strake and I need to build this all back up with west epoxy. Ive read the responses and I really need a suggestion here. A crack along the strake/stringer is not an option! Spent weeks researching and cant come up with a solution.

 

[Tomer9764]

Re: Fiberglass tri hull rebuild

this pic is borrowed but describes exactly the entire hull and the areas mentioned above

 

[Tomer9764]

Re: Fiberglass tri hull rebuild

One layer of 18oz woven seems brittle to me, so does 2 layers of e glass. Csm is out of the question. Biaxials confuse me as well as how many layers i would need. Please help. I need to lay up the whole inside hull before I can move on!