Fiberglass Gas Tanks

customshop05 · #1 03-01-2010, 08:42 PM

Has anyone else built a fiberglass gas tank before? I am not new to fiberglass and have built many custom fiberglass enclosures before everything from body parts to air intakes to sub enclosures to gaguepods with in dash lcd screens but never a gas tank. I Have started and am using the same fiberglass I have used for the past 10 years from my local napa store I have built a styrofoam model that I am glassing as a form and plan on using acetone to clean out the foam. I then plan on using por15 tank coating for the paint so the gas doesnt get to it. I will be doing pinstriping candy color and pearl coat clear a 5 stage paint job when complete using KustomShop paints but didnt know if there were any suggestions from anyone that has done a tank before.....
trk

HseLoMein · #2 03-01-2010, 08:49 PM

Sounds like an idea, but i have some concerns. How resistant to gasoline is fiberglass and resin? Maybe make a fiberglass cup and let gasoline sit in it for a week or so. I like the overall plan, excellent idea!

civlized · #3 03-01-2010, 10:34 PM

I've thought about, but haven't tried it. I think it would work just fine. Not sure about the filler neck and cap. I've used fiberglass a lot, never for a tank though. Let us know how it works out. I am very curious.

**RedB66** · #4 03-01-2010, 10:58 PM

Fiberglass works fine as long as it's sealed properly.

Cannonfish · #5 03-02-2010, 10:50 AM

I'm very interested to see how your fiberglass tank project goes. Been looking at doing the same thing myself - I even made a styrofoam hotwire cutter to make smoother styrofoam cuts, but then I got swamped and I haven't had enough time lately even to try it out.

I'd like to use polyester resin for my tank instead of epoxy resin, because of budget limitations. I did some reading online, and I found a couple of problems with polyester resin for this application: 1) polyester resin will dissolve a styrofoam mold, and 2) gasoline with added ethanol will eventually dissolve a polyester resin gastank.

Solutions that I was considering, other than using epoxy: 1) wrap the styrofoam mold in saran wrap and mist with WD40 (as a mold releaser) to protect it from the polyester, and 2) coat the inside of the finished tank with KBS Gold tank sealer (not Kreem tank sealer, b/c Kreem's website says that it doesn't bond to fiberglass) to protect it from the gasoline.

This is all just from information I gathered online, though - the only real-world fiberglassing experience I have was helping my buddy fix a model once...

**BarelyAWake** · #6 03-02-2010, 11:08 AM

Epoxy can be expensive, particularly ifn you actually expect quality lol Most folks grab for the West Systems stuff 'cause... well... they've dominated the market (justifiably but w/e lol). Check my personal fave MAS epoxies if ya want the same quality fer significantly less cash.

Also remember not all fiberglass mats are compatible with epoxy resins - so double check compatibility

civlized · #7 03-02-2010, 11:54 AM

Thought I might pass along a trick I learned a long time ago for fiberglass when I installed car audio professionally. Old t-shirts or similar fabric rags make great fiberglass shapes. It may not be something you wanted to build a boat out of, but it works great for difficult shaped molds with a lot of curves. Typical fiberglass mat and cloth tear apart real easy when attempting these shapes. No stick cooking spray is also something good to use as a non bonding agent. Wax paper works pretty good to cover a mold, though not as flexible as saran wrap(never tried saran wrap). Wax paper will sometimes stick to the fiberglass and can be a pain to remove. Saran wrap will probably do the same.

customshop05 · #8 03-02-2010, 01:33 PM

I appreciate the comments however I know from personal experience bodyfiller and epoxy resins do not like to stick together for the long term... never looked into why but the surface was properly preped when i put the filler on and about a month of use the spots of filler began to flake off, Never had that issue with fiberglass, the t-shirt for the some of the tight corners is a great idea i might give that a try in the slot and see how she goes, as far as the saran wrap/ wax paper organic solvents that will melt the form out of the inside of the tank so I can pour it out in solution will not melt the the paper or plastic which would leave me with a heck of a mess! Any other Ideas would be awesome. keep em commin!

customshop05 · #9 03-02-2010, 01:37 PM

I wont have to worry about the gas ever touching the fiberglass POR15 makes a inside tank coating normally to protect against rust and corrosion, but i will use it to protect the tank itself. Also I am using a metal graft with a filler neck and fuel petcock inbetween the fiberglass as well as to mount the tank to the frame.

civlized · #10 03-02-2010, 01:40 PM

Quote:

Originally Posted by customshop05

I appreciate the comments however I know from personal experience bodyfiller and epoxy resins do not like to stick together for the long term... never looked into why but the surface was properly preped when i put the filler on and about a month of use the spots of filler began to flake off, Never had that issue with fiberglass, the t-shirt for the some of the tight corners is a great idea i might give that a try in the slot and see how she goes, as far as the saran wrap/ wax paper organic solvents that will melt the form out of the inside of the tank so I can pour it out in solution will not melt the the paper or plastic which would leave me with a heck of a mess! Any other Ideas would be awesome. keep em commin!

Yeah, if your making some sort of container, wrapping the form in anything is a problem. I was just posting some info in case someone might not have used fiberglass much and didn't know.