Technical Fuel cell leak

Aluminum Fuel cell has a small leak on corner of tank. What's a good way to clean tank for welding repair?
Trucke

 

Mark leak, drain & remove tank , fill with water, then turn leak area up & weld it. After welding rotate former leak area of tank down & water will provide "leak check".

 

Check how the tank is mounted too, it has been my experience that when those aluminum fuel cells develop a leak it comes from frame flexing, if you go thru the effort of fixing the leak check to be certain you eliminate the cause of the leak or you'll be fixing it again.
Things are never as simple as they should be.

 

Replace it. 35 years ago I try to repair a leak on a tank. Drained and filled with water and started to weld when it blew up.

 

Was having a conversation with my grandson the other day about this same subject. I explained that I welded gas tanks back in the seventies. I worked at a body shop next to a McDonalds, where the rebar holding the wheel stops, wasn’t drove in completely flush. So occasionally someone would back in a parking spot and the rebar would fillet their gas tank and they came to us, we were in eyeshot. I would flush with water, then I’d take a piece of 1 and 1/8th inch plywood place it top of the gas tank and stand on top of it, torch in hand. I’d light the torch, then stick it up to the filler neck and she’d go whoosh. This was all done in the middle of the parking lot. The plywood trick I learned from a Clown at the local race track. He would blow himself up on Saturday nights. I explained to my grandson, if I would have known about running car exhaust in the tanks while I welded them, it would have been less risky. Remove the oxygen as well as the fuel, and stay safe.

 

If you don't know how , don't do it .

 

Jesus, did you get hurt?

 

Call ex wife new husband ,ask if he will help you on you hot rod. Give him one of those BBQ igniter things and put it in the tank . weld tank

 

When trying to fix a gas tank the worst thing you can do is drain the tank then fill it back up with water because what you are doing is forcing whatever gas fumes remain to exactly where you are going to be cutting and welding. The safe way is to drain the tank then take it to the car wash so you can blast out any remaining fuel vapors with hot soapy water. After that is done blow the tank dry with the exhaust from a shop vac, then once you don't smell any more gas fumes the tank is safe to weld.

 

I've been on a couple road trips traveling with other sort of fast cars, twice I've seen people's aluminum fuel cells that had small cracks that had been repaired, turn into big cracks that dump fuel all over the parking lot.

Might be wise to get a new one, instead of trying to repair it

 

Cheaper and safer, buy a new tank

 

If you are not worried about looks, just fiberglass over the leak. I did that on two different tanks on Semi Trucks Neither ever leaked again . Both leaks were on the bottom. One was large enough to stick my fingers in.

Ben

 

Thanks for all the good advice .
Trucke

 

Seems that many times it boils down to the " I found a way to fix it " camp versus " just go buy a new one camp" , interesting ..

 

I discussed welding gas tanks in the seventies, due to a mishaps in a McDonalds parking lot. But why would some crazy fuck drill a hole in a used suburban gas tank, to change the filler neck location in 2022, to increase his fuel capacity, and weld the new filler neck and fill in the old filler neck hole. Why, because it can be done. I do it all the time. I don’t give a damn what anybody else has to say about welding gas tanks. Let’s review, I’ve been doing it since the seventies. Side note, I drove the suburban in to remove the gas tank. Fresh gas.

 

If you replace the tank and don't fix the "why" or "what" caused the tank to crack as @oj stated then you'll constantly be replacing the tank. I guess if you have pockets full of cash to throw at it then it's no big deal..

Larry

 

Remove it drain it , flush it several times , use a pressure washer if you have one . run the hose from the gas bottle on the welder into it and fill it with a inert gas . Weld it .

 

Not April, So it must be
Trick or Treat !!
Look to be a Trick ,

 

I had a a fuel cell split a seam on a off-road race car and when re-welding the seam we added gussets around the leak and it didn't leak again.
The tank did split along the seam on the other side and I fixed it with epoxy ribbon and a ratchet tie down strap. it lasted to the end of the race (4,000 miles) and was replaced after the event.
A but welded seam will never survive fuel sloshing around in a vehicle driven like a race car or stolen vehicle.

 

You purge the tank with a CO2 fire extinguisher or argon then weld away

 

Dry ice is what you use to de-fume fuel tanks.

 

Years ago I had an OT Austin Healey that had a leaky gas tank. I took the tank to the local radiator shop to be repaired (back when there still were radiator repair shops). Both of the guys that worked there had been there since forever. One guy didn't repair them anymore since he had one blow on him. The other said he still repaired them but figured he would have one go on him some day and then he wouldn't do them anymore. He placed the tank in the radiator hot tank and let it sit for awhile. When he took it out he immediately did the repair. Said something about the tank being still hot reduced the chance of it going off. Have no idea if this is true or not but I do know for a fact based on working at the machine shop at the Army Depot where I was stationed in the early '70's, a gas tank filled with water will still go boom when welded on. Just saying.

 

There are lots of 15-20gallon fuel cells on ebay for under $150, its flooded with them.

 

This is how I've done it before. Wash it out well. Leave a little water and throw in some dry ice. Still has a major pucker factor and I don't do it unless absolutely necessary. I agree with others, you need to find out why it cracked before you decide on how to repair. Was it bad right off the bat or did it crack over time?

 

JB Weld for fuel tanks

 

This is how I did it just today. Purge with straight argon while welding.

 

Another one, for the, FIX-IT CROWD.

 

Did you flush the inside then purge it?

 

Yes. Drained it, pulled the pump and sender out of it, then I sprayed some whitewall cleaner in it and power washed as best I could. I then put a water hose in it and let it fill up and run over for ten minutes or so to shove all the whitewall cleaner out. After all that was done, I let it sit in the sun for a couple days to get completely dry. Then purge and weld. Honestly, it was probably clean enough to weld without purging, but back purging is necessary for good results when welding aluminum.

 

There seems to be a common theme about fabricated aluminum tanks, that they tend to split seams when subject to lots of use. Might be wise to consider why this is, and why it might be better to use a round tank if you need one of aluminum, or find a tank made of a different material if it needs to have a squared off shape.