Fuel Tank Patch?

[Buck]

Hey everyone, been a while. I've been retired from the Navy for 2 years now and seeing the meet in Tacoma coming up finally got me off my rear and starting on the Opel again. Been working on my other project, 84 Toyota pickup, started bone stock, and here's what I currently have. I went to the storage and the GT started up right away, only been about 10 years , but noticed I had a gas leak in the back. Pulled the tank and found that it's rusted out by where the fuel line exits. My question is, has anyone repaired the tank by welding in a new section, after a good cleaning of course. I've gotten quite a bit of experience welding the thin stuff by doing the bob on the bed of my truck, so don't see why it can't be done. Thanks for any input.

[blancojp]

Gas tank is just about the same as a radiator on the Opel. You can cut the area out, install a new patch and bong and you can thread in a new fuel supply outlet.

Make sure you get all of the gas out and clean throroughly prior to cutting of welding. Give is a good coat of paint prior to installing the tank to retard any further rust issues.

[tomcat]

I probably have five extra gas tanks as I have made no effort to sell them. If you want to make it easier on yourself I can send one to you for the price of shipping. I found the best way to ship large items was through greyhound bus. If you want it, let me know your location, and I will get a quote for you. call me at 512-491-0168

[GTJIM]

Welding gas tanks is fraught with (explosive!) consequences.

Even steam cleaning will not remove all the fuel residues from the tank seams - and as soon as the metal is heated it vapourises and turns into a fuel/air bomb in the tank.

One method of reducing the risk is to fill the tank with water just below the weld area to deny the fuel/air bomb a place to form. Another is to purge the tank with a CO2 fire extinguisher as you work to remove the oxygen - this goes well with the use of a MIG welder.

[opelwasp]

Originally Posted by blancojp Gas tank is just about the same as a radiator on the Opel. You can cut the area out, install a new patch and bong and you can thread in a new fuel supply outlet. Make sure you get all of the gas out and clean throroughly prior to cutting of welding. Give is a good coat of paint prior to installing the tank to retard any further rust issues.

I would strongly recommend against welding in a [I]bong[I]. Your local police may not approve.

Try welding in a new bung instead.

[Buck]

Just talked with the "old man", he's been in the gas station tank testing and construction business forever. He says NO WAY, do not weld on a gas tank. No matter how much you clean it, you'll never get all the gas out since it soaks into the metal. Only way to do it is to have a flow of nitrogen going into the tank. He said he had the same problem with his tank and he fiberglassed it, said he'd help me do it next week, so that's what I'll do, than seal it. Thanks for all the input.

[opelwasp]

Well, many have successfully welded gas tanks by filling them with water up to the point plan to repair. That removes the oxygen and prevents flare up.

[neuropel]

I used these guys...they weld tanks all the time but no idea what process they go through first:

Moyer Fuel Tank Renu - antique gas tank repair restoration, classic car gas tanks GASTANK

Todd

[ddoyle]

Repair of gas tanks can be dangerous of course. I never liked welding or using a torch on a tank. Most factory tanks had a thin coating on them, forget what it is called, but its like solder. Large applications of heat can remove the coating, exposing bare steel causing it to rust faster. Not a problem if the tank is to be lined and painted. I fixed a lot of tanks like this... remove paint and undercoating, use a cleaner, carb or brake cleaner, no sanding. The area should be shiny. Form a patch out of thin brass that covers the area, if a large area needs done, a couple patches may be needed. I like to keep patches as small as I can. Tin patches with soldier(40/60) using the right flux. Patch should be covered with a thin coat of soldier. I use a large soldiering iron, about a 2 lb head, electric is best but a torch or furnace heated iron works. Just be sure any flame used to heat the iron is AWAY from the tank. Apply a bit of flux Put iron on the area to be repaired and a little soldier so it has a thin layer of soldier on it. If soldier does not stick, not clean or not hot enough. Should flow smoothly. Place patch on area, I use an ice pick to hold in place, place iron on patch, apply soldier where needed. Nice and neat and no fire on or near the tank. I have used a torch to fix a lot of tanks, but I wont describe or recommend that process. When done with repairs, I like to use RED-COAT(Damon Industries) to line the inside, and a coat of rust proof paint on the outside. And most important, working with any fuel tank, soldier(lead), flux, hot irons, tank liner and paint IS hazardous to your health, be careful or better yet have someone experienced do it!

Dan

[ddoyle]

On a side note I would NEVER use the "fill tank with water" method. This can concentrate the fumes into an even smaller area making tank even more explosive. CO2 or nitrogen with a positive flow while repairs is safer.

Dan

[jordan]

I have used the water in the tank method before, First I drained the tank completely, then I put a garden hose in the bottom of the tank and let the hose run for about a half hour, then I drained it and let water cycle through it for another half hour and left it full that time, I then positioned it so the area I was welding on was very close to the level of water probably within 1/8"

[jeff denton]

Four Winns boats had aluminum tanks with problems in about 1992. They sent us new ones to replace the leaky ones. They didn't want the old ones back.
My boat's tank was steel. And rusting. Causing lots of problems but not leaking.
One of the Four Winns tanks was the right size to go into my boat, but it was leaking at a bottom corner, near but not in a weld.
A local welder said he'd fix that for me if I flushed it out real good at the car wash, using lots of soap and letting it sit full of soapy water for an hour and don't rinse it out.
Upon delivery he put his "sniffer" probe gadget into the sending unit hole, and blew air into it too. He said it was okay to weld, and proceeded to tig a bead about 3" long right next to the corner weld. About fifteen seconds of welding.
Neither of us were killed in the explosion that did not happen at all.

[namba209]

Speaking of fuel tanks, I was NCOIC of a tank farm during my USAF career, how I got that job is another story. It's the place where the external fuel tanks ar stored when not in use on the aircraft. The procedure used for maintnenace on the tanks was fairly simple, drain the residual fuel, purge the tanks with running water for 24 hours, drain and dry, then send them to the Fuel Systems Repair Shop.

[grslightng02]

Hey Buck try looking on craigslist or at your local pick and pull yards for a donor car. I lucked out with my tank recently, I pulled it to clean it and it was clean and rust free, I just sanded and repainted the outside and installed new venting lines.

Being west coast, with the exception of Oregon and Washington rain we don't have as much rust as many other states do. You may be able to find a tank in better condition than yours, take it to the radiator shop for a dip, and then repaint it.

[Buck]

I've checked all the local yards and have only found 1 GT, down in Belfair, that was last year, don't know if it's still there. Was picked pretty clean don't recall if the gas tank was still in it. I'll have to make another round, still going to glass and seal mine this week.