I will be making a few fuel cells for racing vehicles that use methanol fuel which is incredibly corrosive. Every manufacturer i have talked to has said that their epoxy for laminate purposes will be eaten away by methanol. Does anyone know of a coating or resin i can paint/coat on the inside of the tanks that will seal and protect the carbon fiber/epoxy laminate from the fuels?
there are specialty coatings for chemical resistance. Some are for fuels, others for caustics, etc… check with the various chemical suppliers. You might be looking for a vinyl ester instead of an epoxy; they’re usually better at resistance than epoxies.
I haven’t personally used these but I do know they exist. A quick google search turned a few possibilities.
I always use vinylester for fuel tanks.
which one out of thousands ? Vinylester on a epoxy product not that great.
I’ve only ever come across one fuel tank resin - Sicomin SR 8500 / SD 2705. I’ve never used it though so can’t comment on how well it works.
There is also POR-15 Fuel Tank Sealer.
Can you use a vinyl ester resin on carbon fiber?
yes but it does not crosslink well between layers of carbon fiber. It crosslinks better to fiberglass mat/carbon fiber. If your lay up is carbon on carbon use epoxy. Coat the tank with a methanol resistant coating.
Novalac is the only vinylester I have read and researched that will withstand methanol.
Talk to your supplier. Vinylester resin’s chemical resistance is well known. I build my tanks using VE. Not saying it is the best way to do it. But it works for me in an extreme environment. I do not coat epoxy tanks with VE. I work with both Epoxy and VE. Never had a problem with VE/Carbon laminates. And my laminates cop a pounding 
I don’t need it, but the TS does. Your answer was a bit vague, no offence mented ;).
If there is a ve resin that can handle methanol it’s te best to make the rest out of ve also or epoxy on epoxy.
Achemie do a resin that is ethanol/methanol resistant. Give them a call. I use it in my fuel tanks its an epoxy called EP575 and H575…
morepower, do you just slosh a coating of it inside or brush on?