Gas Tank Repair

[jac04]

I just found out that one of my military fuel tanks is leaking on my Lightweight project. I have only put gas in one of the tanks so far, and it started weeping from between the bottom of the tank and the 'cradle' that is spot welded to the bottom of the tank and has the mounting tabs on it. So, fuel is weeping from around the drain plug, but not from the drain plug.
The tank appears to be in perfect shape. I can see inside clearly (the benefit of a military tank) and only the spot welds show minor rust on them. The outside of the tank was blasted to bare metal during the restoration and there were no tender spots.

I'm thinking about using the epoxy repair kit sold by Caswell Plating:

http://www.caswellplating.com/aids/epoxygas.htm

I was going to pull both tanks and do the epoxy sealer on both just to be sure. I really don't want to shell out $400 each for new tanks.

Any other suggestions / recommendations?

[bmohan55]

Mine was weeping from around the plug also, I think I hit it while wheeling. I used JB wet-weld about 5 months ago and no problems since.

[jac04]

^^ So you repaired it from outside? What did you do, just pack the area around the drain with the JB Weld?

[Terrys]

One of my two ExMods tanks was leaking too, but I suspect it was at, or about the halfway point, as it didn't leak until it had 5- 6 gallons (same place most civi 88 tanks rust, where the road crap collects at the cradle tab) I was all set to use POR's gas tank sealer, but a guy came down from Northampton and bought the 109. Joe, at Wholesale, in Granby has the POR in quarts on the shelf. I've heard good reports on that product. I bought a Proline for the 88 I just put back together. It's a pretty nice repop for the money. Why are the Mil versions so much more? Can't be the cap and strainer. I acttually thought of cutting the top of the Exmod, and tigging it to a Proline. I didnt care about the surgery scars, just wanted to keep the same fill spots.

[NepentheSea]

My tank was in great shape except for the weld around the fill tube, where it cracked. It took alot of calling around but I finally found someone who would braze brass around the filler tube. He did a great job and charged me $60 bucks.
Everything was fine until I replaced the rubber connector that connects the filler tube to the gas cap. I torqued on the filler tube too much and the braze job started weeping. I dried it out and smoothed JB weld around the braze, and have had no problems since.
Normally I stay away from the stuff, but its holding up nicely on my tank. It paints well too.

[gudjeon]

I used this stuff,


This way, you coat the entire insides and you won't have to chase little leaks,weeps,or drips later on.

[jac04]

I've been thinking more about this. What has me worried is how good the tank looks from the outside and inside as well. I'm worried that the leak has started from corrosion between the cradle and the bottom of the tank. I guess even if this is the case, then a complete epoxy sealer (one that you slosh around inside the tank) will seal it up.

I'm also concerned about getting the tank clean inside. I cleaned out the inside of the tank with some lacquer thinner, but no matter how much I wipe it down with a paper towel, the towel always seems to come back grey. I think this is because of the zinc coating on the tank. I'll try a fine scothbrite pad and wipe it down some more. And, yes, for those wondering, my arm is skinny enough so that I can reach all the way into the tank.

gudjeon-
Where did you buy the Red-Kote?

[greasyhandsagain]

I had a leaking gas tank also. My method of repair was most unusual, but so far, over several months, has proven to have worked out just fine. I pulled the tank. Since I do a LOT of plexiglass work in my business, I have found that if I take plexiglass saw dust, from the cutting I do, and mix it with liquid Weldon 3 cement, it forms liquid plexiglass. So......I mixed up about 4 ounces of the stuff, and poured it into the bone dry tank, and worked it all around. Let it dry well. After that, gave the tank three coats of black rustoleum paint.

Well....it hasnt leaked in a few months, and the plexi inside hasent came loose.

Naturally my results may differ from others, but I didnt have to buy another freaking tank!!

[gudjeon]

jac04,

I bought the red-kote from a local rad repair shop. They didn't give me a screaming deal on it, but it was better than sourcing/fabricating a new tank for a ser1. If you could get it steam cleaned, you'd be laughing as it sounds likes it in pretty good shape. A rad shop can repair these as well in a similar fashion. You need to use methyl ethyl ketone to remove all traces of water and fuel before application of this stuff. Mine has been holding for 5 years now and quart fo this stuff did my 10 gallon tank twice to be sure.

[jac04]

^^ Thanks for the feedback. I may give the caswell epoxy or the Red Kote a shot. I would normally just replace the tank, but $400 for an aftermarket tank has me thinking about a repair. If it were a Genuine tank, sure $400 sounds great, but I haven't been too impressed with most aftermarket products.
My friends at PA Blanchard have Genuine tanks listed for 179 pounds each, so that't not too bad. I'll get a shipping quote from them tomorrow.

Anyone else have any gas tank repair experience to share?

[graniterover]

I got an estimate for $75 to 'boil' a tank at a radiator shop. I got it back and someone had scraped the outside rust resistant coating off, and the painted it black. The inside was still crappy. The bill was $275. I then ordered a new 'replacement' tank and had it shipped directly to the repair place working on my car (not a rover). The 'new' tank turned out to be a 'refurb' tank and was still full of Sh*t.

The lesson for me was either:

1. Do it yourself and get it right or
2. Buy a replacement with piece of mind from a reputable dealer with a warranty

Sounds like your issues might be minor though.

If I were you, on this truck, I'd sell the old tank and let the buyer know it has a leak but is rust free, and I'd buy a new tank. Piece of mind must be worth a bit on this project.

[greenmeanie]

I used the POR15 stuff on my 109 tank that was leaking in a similar fashion. It gets expensive for if it is to really work you have to clean the inside very, very well. The fuel varnish stops many things sticking properly.

It worked very well but was a real skiddle of an operation. You have to use the marine clean stuff first, rinse, metal ready stuff, rinse, let it dry very well and then put in the sealer which is like a silver paint. Each step requires lots of agitation to make sure you get all the internal surfaces. I think the neighbours thought I had finally lost it as I stood in the driveway shaking a fuel tank and screaming to myself for most of a weekend.

I'd most likely pay the money to have the rad shop boil it out and redkote it next time.

[Rineheitzgabot]

Jac,

If you are going to have to empty the tank, and dry it completely, I would recommend welding the spot, or area, on the outside. After the area has been repaired/welded, clean said area very well, with a wire wheel, removing all slag/buildup of paint dust/other grime. Make sure everything is tight, and figure a way to compress air in the tank (this does not have to be fancy, just using a wet rag, around the end of your air nozzle with a tight grip). Pour soapy water over the area while it is compressed with air. Look for leaks. Do this several times.

We manufacture industrial equipment that is powered hydraulically. The tanks are anywhere from 30 to 100 gallons. About 3 out of every 40 tanks come to us with some sort of leak, just like you are describing; right around the bung (not where the plug is threaded, but where it is welded?). This is how we do it.

Of course, if you don't have access to welding EQ, then nevermind. My apologies if this is obvious, and you have elected to not do it. However, it is probably the cheapest, most reliable method.

That thing is looking great, and I wish I had the time and patience to do what you have done.

-Gary

[jac04]

^^ The problem is finding where the fuel is coming from. I obviously know where the leak is manifesting itself, but somehow the fuel is getting in between the 2 bottom plates.

[Rineheitzgabot]

Sorry. I misunderstood.