Fiberglass Gas Tanks

Discussion in 'Motorized Bicycle General Discussion' started by customshop05, Mar 1, 2010.

  1. customshop05

    customshop05 New Member

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    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
     
  2. HseLoMein

    HseLoMein New Member

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    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!
     
  3. civlized

    civlized New Member

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    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.
     
  4. RedB66

    RedB66 New Member

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

    Cannonfish New Member

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    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...
     
  6. BarelyAWake

    BarelyAWake New Member

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    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 ;)
     
  7. civlized

    civlized New Member

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    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.
     
  8. customshop05

    customshop05 New Member

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    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!
     
  9. customshop05

    customshop05 New Member

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    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.
     
  10. civlized

    civlized New Member

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    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.
     
  11. civlized

    civlized New Member

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    I have made a lot of kick panels for speakers and speaker boxes that fit in spare tire wells with fiberglass. T-shirt material is the bomb for that kind of stuff.
     
  12. Cannonfish

    Cannonfish New Member

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    Just thinking aloud again...

    What if you used wax paper/saran wrap/etc to protect your styrofoam during the fiberglassing, and then after it's cured and you've melted the styrofoam out, you could cut your tank in half. Then it would be easy to extract the wax paper/saran wrap, and you'd also be able to fully visualize your tank sealant coating all the interior surfaces.

    When this is done, you could just fiberglass the two halves back together? And then slosh a little more tank sealant around in there to make sure the gap is coated on the inside?
     
  13. NewOrleansFlyer

    NewOrleansFlyer New Member

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    Used to cover high powered rocket tubes with.....panty hose!
     
  14. 2door

    2door Moderator
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    We used to build fiberglass wings for R/C airplanes that way. Cover the foam core with the one leg of a pair of panty hose then start applying resin. Seemed to work just fine. Never had a wing fail.

    Another option is the way I did my chopper tank. I encased a steel tank inside of a foam and fiberglass shell. That way I never have to worry about leaks and I got a tank the shape I wanted. Just a suggestion.

    Tom
     
  15. thegnu

    thegnu New Member

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    yes he did a beautiful job on that tank .
    why not try making your foam core an lining it with aluminum foil , the heavy duty stuff,an build your fiberglass over that ,that would limit the amount of surface area that fuel an oil will come in contact with the glass, or another option is vacuforming theres much info on the web about that an theres many more fuel resistant plastics available , or a freind of mine used to make reproduction parts for the older chrysler muscle cars by using resin an molds , to my knowledge there is a resin formulation resistant to fuel an oil , just cant remember for sure , check it out .
    Gary
     
  16. b-rad

    b-rad New Member

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    I know back in the seventies at least ..Maico motocross bikes sported fiberglass tanks.. there is probably some info out there about they"re processes
     
  17. rickenbiker

    rickenbiker New Member

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    I dislike the look of a peanut gas tank on top of the top bar on nearly any style of frame...it has always looked like an afterthought to me...and I'm old enough to remember original Whizzers, too.

    As I get into my '53 Schwinn Phantom Whizzer buildup, I'll be pulling molds from the Phantom tank, in order to to make it functional as a gas tank. It'll be slightly wider than stock, two separate sealed pieces, bolted together, with balance tubes at bottom.

    Yes, I've done lots of fiberglass work, and I teach advanced prototype building at university level. The only issue is finding time for all this fun!
     
  18. tooljunkie

    tooljunkie New Member

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    paint the por15 on the mold,if its gas resistant,than it should work.my supervisor builds surfboards as a hobby,he paints the foam with latex before glassing.but he doesent need to remove the foam afterwards.
     
  19. HarryO60

    HarryO60 New Member

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    Please be very very careful about fiberglass gas tanks. Ethanol and fiberglass do not play well together. My main hobby is boating and the boating industry had fits when ethanol was introduced. Bertram boats were built with fiberglass tanks that were also structural. Ethanol added to gas caused these tanks to break down and clog filters, carbs and injectors. The only option was to cut open the deck and remove the tanks, rebuild the stringers and install new aluminum tanks.
     
  20. customshop05

    customshop05 New Member

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    Well the tank lasted for about a year then it cracked from the vibration and started leaking fuel. So now it is garage art! After that happened i sold my highly modified motor and many of my parts to a gentleman in Texas. I now have a little more money to play with bigger projects so I have moved back to working on them.
     

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