Balsa and Fiberglass Fuel Tank

Chris,

Your obviously into boats and sounds like you definately know your stuff! With regard to polystyrene, wouldn't it react to regular mat and resin that you would fix a Corvete with? The stuff you'd use w/ a paint brush....

I know I ain't got money for a fancy chop gun!!! Looks like I'll be sanding alot!

On second thought, within the next few days, I'll give a small piece a try and let you know what I come up with. I've got alot of ambition toward this project.

For greater clarity on your advanced terminology, I can assume that roving is fiberglass shavings mixed with catalized resin... I've got experience working on VET's and stuff but the application of materials is different
 
Last edited:
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.

This is correct, and I've posted this a couple times in response to some other threads too. Fiberglass tanks are not new, and are used in boats and airplanes all the time. Nortons used to use glass tanks back in the day. As long as you use epoxy resin and not polyester, you will be fine. Kreem could be used, but it's not necessary IMO.

The lost foam plug method you describe is ideal for one-off production. There's no need for balsa wood. Just get some of the pink or blue foam insulation sheets, tack them together with a couple dabs of wood glue, carve them into the shape you want and then cover it with glass. I've never heard of using gas to melt the foam. I usually see people using acetone. But hey, whatever works.

The only thing that has ever stopped me from doing this (aside from having recently sold my motor and mounting kit) is that I couldn't think of a good way to mount the tank.
 
This is correct, and I've posted this a couple times in response to some other threads too. Fiberglass tanks are not new, and are used in boats and airplanes all the time. Nortons used to use glass tanks back in the day. As long as you use epoxy resin and not polyester, you will be fine. Kreem could be used, but it's not necessary IMO.

The lost foam plug method you describe is ideal for one-off production. There's no need for balsa wood. Just get some of the pink or blue foam insulation sheets, tack them together with a couple dabs of wood glue, carve them into the shape you want and then cover it with glass. I've never heard of using gas to melt the foam. I usually see people using acetone. But hey, whatever works.

The only thing that has ever stopped me from doing this (aside from having recently sold my motor and mounting kit) is that I couldn't think of a good way to mount the tank.

You mentioned earlier that fiberglass matting wasn't necessary, and that some regular fabrics would work. What regular fabrics do you think would work well? Denim, cheesecloth, burlap, something clear or translucent?, Fishnets even? Trying to be creative...

I'm liking this idea because I could make a plaster mold of my wine bottle, pour some spray isolation foam in, and then use that form to have a fiberglass wine bottle.

Also, as far as mounting goes, could you embed some mounting hardware in the fiberglass? Like some steel brackets or something? Or possibly use some mold release spray on the top of the frame after the tanks is mostly done, and then make two ridges with your original material to partially cover the frame, and then epoxy that? Then build some mounting hardware to bolt to the flanges?
 
My idea for an Indian style tank was to use a piece of steel tubing or have a sheet metal shop roll one out to size and cap the ends as was mentioned.
Glue a coloured foam[not styrofoam] to the ends and shape it. You can buy the foam at a builders supply or check the dumpsters at a constuction site.

I have heard both fleece cloth and spandex cloth work to cover the metal and foam. Just soak the material with resin and sand smooth when it is dry.

For the filler tube I plan to use a car, gas filling tube. The first part from the cap down to the rubber hose that goes into the tank. Look under your car and you will see what I mean.Drill a hole in your tank with a hole saw and weld in the cut off tube and wrap the tank.

For a square tank, I'd cut the side panels to shape and cut a strip of metal long enough and wide enough to wrap around the full length of the tank. Just one seam where you join the ends. Recess the side panels in an 1/8in and solder the tank together. Check for leaks. I don't plan on using really heavy body metal for this. Thin and bendable so it's easy to work. Probably galvanized to protect against the new gasoline.

Wrap the tank in a thin layer of foam glued to the tank and shape the foam to what you want. Round edges ect. Wrap the tank as above.

Hope this all makes sense.

Steve.
 
Last edited:
Fiberglass is a better material because if for some reason the resin gets a break in it, other materials will attract fluid!
 
machiasmort, I agree with you. My thought is it's just a gas tank,not a boat. If it is damaged it will be repaired quickly. Just as soon as the crashee heals. I spent a few years in the fiberglass industry making every thing from septic tanks [the low] to Everitt-Morison's Cobra kit car bodys[the high]. In between there was work for Disney World and a couple of drag car bodys, race cars,boat shops, hot tubs, ect. Mostly job shop stuff.
Never did a Corvette repair though.

Thinking that spandex/fleece would be easier to use and would be nicer to use than glass. Do you remember the itch or did you have a good vent system where you worked?

Steve
 
FE,
I'm sure you know more than me then! LOL

Promised I'd post my findings. Here they are.

Used thin styrofoam 1/4 thick and placed small ammount of BONDO (polyester) catalized resin onto it. It ate through in less than a minute!

On the possitive side Caswell makes a sealer that will seal polyester resin against gas, or so they claim.

In conversation here, I'm having trouble understanding the difference between epoxy and poyester resin. What is a good local source of epoxy fiberglass resin fitting this application? I've read a few other posts which also agree that a sealer is not required with epoxy. My main issue is that these morons get on the internet and blab about stuff they have no clue. I've read alot of conflicting information regarding resins and the process of application, sanding ect.
 
machiasmort, I agree with you. My thought is it's just a gas tank,not a boat. If it is damaged it will be repaired quickly. Just as soon as the crashee heals. I spent a few years in the fiberglass industry making every thing from septic tanks [the low] to Everitt-Morison's Cobra kit car bodys[the high]. In between there was work for Disney World and a couple of drag car bodys, race cars,boat shops, hot tubs, ect. Mostly job shop stuff.
Never did a Corvette repair though.

Thinking that spandex/fleece would be easier to use and would be nicer to use than glass. Do you remember the itch or did you have a good vent system where you worked?

Steve

Alternative mats, I'll be honest, I never thought of... Brilliant idea! Afterall it is only the resin that seals! Just wouldn't do it to a tank tho. Just my opinion. On a cracked ferring, all day long! I get that itch worse than most, It's a serious drag!
 
Fiberglass tank

Hi all
Here is a tank I made about 6 years ago from tap plastic epoxy and fine fiberglass. It was a lot of work I made a plug or male mold in two haves after about 6 layers aprox 3/16 in I trimmed and joined the two haves with thickened epoxy. I first glued small tabs made from epoxy and glass to each half so that when the two haves were brought together the
tabs forced the edges into alingment, half of the tabs were on one half and half on the other. the bead of thickened glue along each edge flowed together over the joint.
Brent Merkley
 

Attachments

  • 039.JPG
    039.JPG
    362.3 KB · Views: 535
  • 043.jpg
    043.jpg
    73.4 KB · Views: 473
  • DSC00699.jpg
    DSC00699.jpg
    67.3 KB · Views: 464
  • DSC00946.jpg
    DSC00946.jpg
    63.6 KB · Views: 482
Back
Top