Epoxy vs Vinylester

[Seacraft84]

I agree with all the above. Epoxy is alittle stronger. But you have to think these boats are polyester and the glass on mine is still in very good shape. It has held up 34years so far. I would definatly use epoxy on a bracket though.

Kenb.. I have used about 1.5-2 gal. of qiuckfair and I am very pleased with it. Just get a digital scale to measure it out with. I have also used west sytems 407 and 410 fairing filler and they are also good. So for a large surface I would use quickfair.

[Finster]

Just my 2 cents but I've used both and I'd stick with poly or vinylester. Epoxy is strong but annoying to work with, try laying something up on a vertical serfice lol, good luck.
Remember, these boats are all made with poly and are stong and solid as hell. You not going to reinvent the the wheel by using epoxy.
Btw, I have gallons of system 3 if anyone wants it...yuk!

[Seacraft84]

I will take you up on this offer. I could use some epoxy to make my fishbox. Give me a call to set up shipping 252-342-2509 Thanks

[dbiscayne]

poly & vinylester are fine on a new build, when laminating wet on wet layers of material, but you'll never get as good of a bond onto something thats already cured. Thats where epoxy has such an advantage, a great secondary bond. It's also easier to mix, doesn't smell as bad, & has a longer working time. But you can't put gelcoat on top of epoxy.

[liam]

Hey Dave based on the speed you are working at I would be more concerned with which product has the longest shelf life

[hugo]

befor starting my rehab on my 20 SF i went round and round trying to find out which is realy the best to go with and in the end i used poly, the price was realy the deciding factor for me. im sure the epoxy is a better product but in the end but i kept being told it would be good for a liftime.... but i hope its not my last boat so if its good for another 10 plus years thats ok with me. as for molding in a bracket that is using no fasteners i would go epoxy.

[FishStretcher]

Vinylester and polyester aren't the same thing. I had it explained to me that it can be thought of as similar to a polyester at one end, and similar to an epoxy at the other end of the chain. With properties in between.

My one class in composites was back in the 1990's so take it with a grain of salt. I do know that the curing agent is more like polyester.

I used vinylester last year, and it sticks to polyester and epoxy. I used it as a primer coat between epoxy and a polyester gel coat, and it is tenacious. I hear it is often used as a barrier coat on epoxy sailboats.

I like it enough that I want to use it more. It is safer than epoxy from a sensitization standpoint, higher performance than polyester, and compatible with either.

[gofastsandman]

Originally Posted by FishStretcher

Vinylester and polyester aren't the same thing. I had it explained to me that it can be thought of as similar to a polyester at one end, and similar to an epoxy at the other end of the chain. With properties in between.

My one class in composites was back in the 1990's so take it with a grain of salt. I do know that the curing agent is more like polyester.

I used vinylester last year, and it sticks to polyester and epoxy. I used it as a primer coat between epoxy and a polyester gel coat, and it is tenacious. I hear it is often used as a barrier coat on epoxy sailboats.

I like it enough that I want to use it more. It is safer than epoxy from a sensitization standpoint, higher performance than polyester, and compatible with either.

Nitrile gloves. Nice properties.

[flyingfrizzle]

I have herd that the epoxy is more flexible than the poly but was wanting to know if done right will the poly hold up to a lot of flexing. Don't want to have stress cracks develop if the boat is getting a lot of pounding in a ruff water conditions being ran hard. The poly I can order a 55 gal barrel for $975 and the epoxy is over $2700. Also I have herd that poly has a shelf life of only a year or so. That worries me on getting the 55 gals. Will it last longer if it is in a controlled environment and if so what temp dose it need to be stored at?