Thinning epoxy

May generate heat !! thats an under statement !! take you dinner it could be better than a bar-be-que !!!

 

I've never used polyester resin before. Does it generate less heat than epoxy?

I sort of feel like 28 layers is more than enough for the strength I need in this boat, but I feel like I should build to the designer's specs.

 

There are many formulations for polyesters and VE's, you can get types that are designed to be used in very thin laminates or very thick, from 1/8 to several inches and the exotherm will be in the correct range for the thickness.

 

28 layers is what you would find in a battle ship !!!what the hell are up building ? a bomb shelter?

yes poly will get hot ,so will epoxy!!! if the heat gets to extreme then it was do more damage than good so all that strength you thought you had ,well part is lost because you cooked the resin and it becomes brittle and next to useless .
like all things there are limitations of what you can do and what you shouldnt do .

 

Please post some pictures of what you are doing !!

am i hearing this right a centreboard core ??? discribe please and post a picture or two or three what it is exactly you are making !!. there is no where in any sized boat that would need that amount of glass for anything to do with a cenretboard or the case !! triaxle as well !! i am sure you have your wires crossed who ever said to make anything with 28 layers of glass and epoxy ! thats crazy .

 

I'm building an 18' folding trimaran. The design has two main structural members that are essentially beams crossing through the main hull. The beams stub outside the hull and this is where the folding linkages bolt through. Basically the beam mount area shown in this diagram, only on my boat it's an external attachment - ie. this is a female version, mine is a male version. There is a core and 14 layers per side (28 total). The areas on the beam where the links bolt are pretty similar thickness.

 

Ive built thousands of snowboards with 22oz triax and epoxy, the best way we found was to wet out on a bench, lay down epoxy, lay the glass in it and work it through and add more from the top,and if possible let it sit a while we used press molding epoxy and cooked at 100 degrees C under 30 tons of pressure for 12 minutes and all extra resin is squeezed out. How ever my feeling is that unless you are using wood as a core you will get a better resin to glass ratio in a hand layup with vinylester than a a gp epoxy, even the thinner ones are more viscous than vinyl. I just got done with some projects where we went through 15 gallons of Pro set epoxy and im now even more convinced to use vinyl wherever possible.

Steve.

 

I'm building in a residential area, so generally polyester and VE are not going to work because of the smell. I think I could get away with at least using it for the beams though because they are bolt on at both ends - no glue contact with epoxy components.

 

all these things you building sound like a good reason to do infusion of epoxys or Vinylesters and cut down on the smell a lot !! ask herman what is your best course of action hes an infusion person !!

 

No need to get that complicated, you are doing a one off mate, just pull it down with a vacuum or weights. KISS method.

 

Jetboy,

What boat are you building? That certainly looks like a Farrier, but I don't know of an 18' by him. I've asked him in the past and he said there was no commercial market for a boat that small.
18 plies of 22 oz seems heavier that anything I would believe necessary on a centerboard trunk. Not a criticism, just outside of my experience and I want a boat about the same size, so I am interested - what is it?

 

It's a Scarab 18. Very similar to the Farrier boats in shape and general design. Just smaller to better suit my needs. - Here's a better idea of what the folding mechanism looks like. I dont' want to put pics from the actual plans on here because they are protected intellectual property. Here's one I found on the web. You can see the beam stubs on the main hull. Those continue through the hull and are one piece that takes the majority of the load of the righting moment.