Building a fiberglass fuel tank and using aluminum fittings?

Can someone point me on how to build a fiberglass fuel tank and use
aluminum fittings?

Thanks
Bill

On Feb 4, 10:37 am, wrote:
Can someone point me on how to build a fiberglass fuel tank and use
aluminum fittings?

Thanks
Bill

You might get some hints from various sections of my web site.

www.kisbuild.onfinal18.com

There are several examples of the fittings on the wings of both the
KIS Cruiser and the TR1. The main thing you need to do is bond in
aluminum hard points on the inside of the tank for your fittings to
connect. Pre-tap the hard points threads to keep any shavings from
getting inside the tank.

wrote:
Can someone point me on how to build a fiberglass fuel tank and use
aluminum fittings?

Thanks
Bill


John Dyke's Delta design calls for two steel plates to sandwich the
fiberglass wall. The fittings are welded to one of the plates. Lots of
sealant goop all around.

wrote:
Can someone point me on how to build a fiberglass fuel tank and use
aluminum fittings?

Thanks
Bill


Make a tank shape on a mold, with one side missing, and make the missing
side as a cover. Alternatively you can use a consumable mold and simply
make an access hole large enough to do the following:

Bond/Epoxy some flat plate aluminum stock. At least 3/16 inch thick..
depending on the size of the fittings, but you want to engage at least 3
threads or so on the fitting.

Rough up the aluminum stock (at least 1" square area for each fitting
penetration). Overlay with BID to sandwich the stock. Drill, Tap,
Install fitting.

Bond/seal the tank with something fuel resistant. Jeffco comes to mind.
It also is prudent to make the tank with fuel resistant epoxy in the
first place, particularly alcohol resistant since that seems to be the
future of Mogas.

Dave

Hi Bill, here is a reply from Corky Scott to me when I asked the same
question. It came in very handy and I'm just finishing up my tanks
now, or when the temperature get above 0 again.l

I'll try that again.

Lou

There are several ways to do it using fiberglass.

I don't personally remember the type of foam board to use, but Wicks
does, just ask them. If you choose to use the 1/4" foam board, you
cover both sides with two layers of fiberglass and then cut out the
pattern.

You assemble the tank and bond the pieces together using a slurry of
resin and flox. Make up a slurry of glass beads (looks like powder
but is actually microscopic glass beads) and resin such that it's like
putty and lay it into each joint and using a spoon or something
similar, radius the putty.

Overlay each joint with two layers of fiberglass tape, two inch and
four inch. Put the two inch layer down first, and overlay the larger
layer second. Smooth the tapes into the corners as best you can.

When all is cured, you get to make the various holes necessary for
things like the vent, the drain the fuel sender and the gas cap.

A really neat way to do this is to use a dremel tool and cut hole two
inches larger around than whatever is going there. Lift off the layer
of fiberglass revealing the foam below. Radius the foam down to the
outer layer of fiberglass so that the foam slants towards the middle.
The radius doesn't have to be real gradual, it's just that you don't
cut the foam straight down to the outer layer. Cut out about 6 to 8
round patches of glass, each one slightly larger than the first, and
the first has to overlap the hole by at least half an inch.

Soak the smallest patch with resin and lay it in the hole. Soak the
next bigger patch and put it on top. Continue this until you have all
the patches installed. Let it cure. When cured, you will have a very
very strong hardpoint for the drain, or vent outlet or whatever.

Varying the size of the hole works for the gas cap too.

Now add anti surge fences to keep the gas from racing like a wave from
one side of the tank to the other. These should be double faced foam
board too. Bond them in place and do the radius thing with them too.

You can bond in a layer of foam along the top of the tank if you wish,
flush with the top edge. This will give you a nice large edge to bond
the top of the tank on. But you don't really have to do that.

Bond the top of the tank using the slurry of flox and resin, let it
cure.

Using a good mask, round down all edges and corners using an angle
grinder and appropriate rough disc.

Blow it off and apply two layers of fiberglass tape, 2 inch tape
first, 4 inch tape on top.

You will end up with a REALLY strong and leak proof gas tank, **IF**
you used an approved resin that has been proven to resist all fuels
that will be used.

That's one way.

Some people don't use foam board, they just lay up several layers of
fiberglass on a large work surface and once cured, peel it off and use
the sheet of cured fiberglass to create the gas tank.

Still another method is to create the gas tank out of a foam board
that melts in the presence of gas. Coat the foam with fiberglass and
then cut a hole in the fiberglass and pour in gas. The gas melts the
foam, and you pour the yuck you're left with out and you have a tank.

Or you could work with some plastic firm and have them cast you a tank
out of plastic.

I made two of the first variety, and tossed them both out because they
were too heavy and I was disappointed with their capacity.

Corky Scott

Many years ago (about 40), I made a tank for my smith mini by cutting blocks
of white Styrofoam
into the desired shape,sticking a VW gas cap and nozzle into the top and
sticking the fittings for
the outlet in the bottom. Then I covered the whole thing with fiberglass
matt and epoxy resin.
After curing, I just took off the gas cap and poured acetone into the
opening. I had to pour slowly
to allow it to work (dissolve the Styrofoam). After pouring all the sludge
out and allowing time for
the remainder to harden, I mixed up some sloshing compound and sloshed the
tank. As a final
task I covered it all with fiberglass bi-directional cloth and epoxy resin.
Was still working fine last I heard.
Chuck

wrote in message
ps.com...
Can someone point me on how to build a fiberglass fuel tank and use
aluminum fittings?

Thanks
Bill