I've seen gas built from fiberglass before...and actually, I've been thinking of doing this exact thing. For some reason, I feel like I would want fiberglass cloth inside....but it may not be necessary.
For what it’s worth, I won’t be a stuck up crybaby like a few others around here and will share some knowledge.
Great idea with the sealer, I wouldn’t have thought of that.
I would however stay away from fiberglass cloth as the structural material and instead opt for mat. The fibers in mat go different ways, making it more porous but the positive trade off to porosity is strength.
One consideration is to make sure it’s vented real good with a cork and copper winding like the old school.
Saw an article in Cycle World this month that talked about a fiberglass gas tank that started to dissolve enough to leak and clog carb parts. Seems like the Kreem or similar product would take care of that.
I know that there are alot different products out there (tank linners). Oil and petrolium type products are of the same base that mat and resin is, believe it or not! It's very likely that if the linner failed there would be rather swift consequence.
The linner itself is a serious consideration that I will have to look into and report my findings. Of more serious detriment to the idea is that it would have to be cast in 1 piece. I think trying to join numerous pieces together would pose structural risk given the vibration we experience. I've applied linners before, to steel tanks tho!!! Big difference! I didn't pay attention to the name of the stuff but know it was a pretty penny!
Probaably more artsy, but what are people thoughts on a glass bottle with some sort of additional resin liner (something more structural than the Kreem) on the inside, and a resinn+cheesecloth wrap on the outside?
Ehhh! I'd stay away from glass on a MB. Just my opinion. Some may argue but I seen what happend to a friend durring a pedal bike crash when younger. Had a beer bottle in his hand and one in his drinkholder. When he wipped out, he came up looking like a rag doll that encountered a pitbull. Not a good seen, 100's of stitches.
Fiberglass tanks seem to be pretty common in the boatbuilding industry.
Epoxy is a much tougher resin, and I imagine that it is, or could be rendered fuel proof with an appropriated addative or coating.
Instead of balsa, you could make up a plug mold out of expanded polystyrene (styrofoam) and lay up your tank with successive layers of cloth or matting and resin. While another poster suggests that mat roving is stronger (he is right) the woven polyester cloth is easier to form into compound curves because you can stretch it along the bias (diagonal to the weave) much farther than you can stretch it in either direction along the warp or woof of the fabric. The roving is sprayed out of a chopper gun and has no "grain."
There are also boat repair shops that use chopped matting---that's a deal where chopped up fibers and resin are sprayed out of a special tool similar to a paint sprayer to build up successive layers.
The beauty of the styrofoam is that once your get your tank all laid up and nice and smooth like you want it, pour a little gasoline in it and the foam will turn to liquid and you can pour it out. CAREFUL, you now have what amounts to napalm---nasty gooey stuff that burns and sticks.
I thought about punting and just building a decorative shell or case around a metal tank.