Fiberglas patching on gas tank?

[Napes]

Are most automotive fiberglass applications fuel resistant? Not on my car, but on a colleague's older pick-up's gas tank. TIA

Bob Napier

[Mike Self]

It'll eventually leak, probably at an inopportune moment.

The best way to repair is to take the tank out and to a good radiator shop. They should fill the tank with inert gas (NOT water) and weld/braze/solder it up.

Gasoline is scary stuff; don't tempt fate with a half-vast repair.

mike

[Otis]

I think you have to separate the concept of patching, which (as Mike says) won't work/last for a variety of reasons, and the concept of a fiberglass gas tank - like those used in boats, or in underground storage tanks at gas stations.

In general, however, I would not use fiberglass gas tanks, given the trend of blending ethanol.

http://www.beyondfossilfuel.com/ethanol/fiberglass_tanks.html

Ethanol apparently (or at least allegedly) causes deterioration, which (leave it to the lawyers, of course) has spawned a cottage industry of class-action law suits.

http://boatingsailing.suite101.com/blog.cfm/ethanol_fuel_tank_damage_suit

[PatAllen]

i fixed mine and welded it, and i did this many times on other tanks...

I empty the tank and let the spout downward because gas vapor is heavier than air, so it will get out faster.

After one week or so, i put the spout next to a car muffler outlet and make the car run for 10-20 minutes so the exhaust is going into the tank.

After, i can throw a lighted match in and it dont blow (!). This is an old man trick that ive seen many times so i was not scared to do it. Sure enough i can hear the fags screaming of fear...

I am using a poor man flux core to weld it/patch and then i pour any stuff to seal it totaly (POR15, KREEM,...).

Never had any issues and it seems to last forever once its done.

hth

[Beaner7102]

I can highly recoment the POR-15 Fuel Tank Sealing kit. Has all you need to clean and completly seal a tank (inside and out).

No leaks after 3 years with E10 fuel too.

Beaner7102