Chief Fuel Tank Repair Advice

[41Chief]

The restoration of my 1941 Chief is turning into a never ending saga. Anyway, the decals on the fuel tanks started to bubble up and the paint was fading so it needed a paint job. So, I had them blasted and chemically stripped. When I got them back, there were several dents that had been bonded over before on both tanks. I can re-bondo those.

The problem is that in the right hand oil tank, the fittings for the oil lines have become loose on the inside of the tank. They could have been fastened by epoxy or glue before; I do not know.

What is best way to secure those so that they do not leak? I was thinking silver solder or brazing from the outside / bottom but I am wondering if the fuel tank should be taken apart and then soldered / brazed from the inside instead. What I do not want is to discover that the gas side is leaking into the oil side or have the solder / braze come apart when I am driving the bike down the road if I ever get the thing running again.

If I need to take the tank apart, what is the best way to do that without distorting them, or otherwise going from bad to worse?

Thanks for any tips.

[T. Cotten]

Trust your instincts, 41Chief!

If a joint has previously been soft-soldered like the rest of the tank, then it is best to avoid silver-solder, as they are not compatible.
Soft solder can be fun; I prefer a large iron, sometimes with a simultaneous hot air gun. Takes three hands.

"Brazing" is pretty harsh, as 'admixture' can ruin the terneplate.

Please remember that whatever you take apart will be broken, and just another thing to fix.

....Cotten

[tfburke3]

Its not a job for the typical garage mechanic,like me.Advertiser in the mag does what is probably the only sure fire way.
Tanks get completely disassembled,stripped.tinned and resoldered.Probably more practical for a rarer or more valuable tank.
Last year in the same boat I boughtt iron Horse coral repros for about 700 for my 38.The tanks needed the slightest tweeking on front bracket but overall beautiful.All welded.I primed in DTM epozy so they wouldnt rust before I got to them and they need almost no body work.6mo wait was more like 8 but I was best choice for me.If I was in you shoes I would just replace them.
TOm

[jcrawford]

41Chief,

Here is Matt Blake's Iron Horse Corral website:
https://www.theironhorsecorral.com/
standard size or "long range" extra capacity tanks available

[jcrawford]

41 Chief,

Refer to Vahan Dinihanian's ad in the AMCA magazine and back cover of 2020 Membership Roster for tank repair.
Dinihanian Manufacturing, Inc. is in Portland, OR

[exeric]

Unless you're married to the tanks you have, I would take Tom's advice and go with welded Iron Horse tanks.

[T. Cotten]

Unless you're married to the tanks you have, I would take Tom's advice and go with welded Iron Horse tanks.

The consensus seems to be, 41Chief,...

Throw money at it.

If you can't fix them yourself, they're just scrap or wall-hangers, right?

So why not try?

...Cotten
PS: Lotsa Folks cheat themselves out of the most rewarding experiences of reviving a Historical machine.

[jim d]

If you decide to repair them I would go with a soft solder lead tin base. Trying to use brazing or silver solder with the soft solder will be a real train wreck. The winter 93 and spring 94 AMCA magazine has a two part tech. article on rebuilding and repairing the soldered fuel tanks. The last three or four years of production the Indian tanks were silver soldered together. I had a oil tank with a crack in the inside wall leaking into the gas tank part on a tank that was silver soldered together. And I repaired it myself, so if you have the skills what do you have to lose but some time. Whatever you decide weather new or repair the original tank I would pressure test both gas tanks and the oil tank.

[stan]

The fittings should be screwed into a thicker metal plate soldered inside the tank. Silver soldering should not be done. The heat will travel to the tank seams, and the dividing wall to the gasoline. Then you will have a bigger leak. If it's real clean, you may be able to add solder at the fitting using 50-50 solder and acid to clean the area. Too much heat and the whole metal base will come loose. I use a propane torch, just be quick about it. Stan

[Qtaug]

The tanks on my 47 Chief were beyond repair, went with tanks from Iron Corral. Great choice! The only issue I had was the 8 week delay, as they are made to order.

[T. Cotten]

Whatever you decide weather new or repair the original tank I would pressure test both gas tanks and the oil tank.

Jim is right, of course, Folks!

But beware anything over a few psi risks bowing out any flat surfaces.

The safest way to leak-test a tank is to cap it up securely and immerse it under hot water, so heat expansion provides the pressure.

...Cotten

[exeric]

I repaired the original tanks on my '40 Chief and it was a lot of work. They have to be completely disassembled, scrupulously cleaned, and repaired. Some people have the tank parts copper plated to make repairs, and re-assembly easier. I made fixtures to relocate the mounting brackets, and to keep the tank body from warping when re-soldering the tank back plate. I have a collection of large copper soldering irons that must be heated with a torch and they have proven to be the best tool I've used for re-seaming thin sheet metal. You can use a torch to disassemble the tanks, but it is very tricky to use a flame to reassemble the tanks . As Stan said, 50/50 solder, and quality flux on super clean metal. So, don't buy the Iron Horse tanks because you'll just be cheating yourself out of months, and months of fun

[Lipdog]

I live in the SF Bay Area and looked into minor tank repair earlier in the year. Almost no one would do it. And the one guy who would charges almost as much as buying a new tank. And getting it painted is another issue, no one wants to do that here either. So I don’t think a new tank is such a bad idea.

[T. Cotten]

I re-soldered a petcock bung without even ruining the paint, Folks!

It t'aint rocket surgery if I can do it.

Ruby Fluid is essential (along with patience, careful observation, preparation, and the right tool for the job).

....Cotten

[tfburke3]

Indian took a step backwards with the tanks after 35 or so.The earlier,like 34,tanks had a right side oil and gas tank that were separate,with an air gap between each other.
No possibility of gas and oil mixing because of leaky divider.But I guess to cut costs they went to one common panel between the oil and gas.Get a leak there and you may not notice until out for a ride and your motor siezes.Happened to my friend and he had 53 brazed tanks.
Tom
Ps Tom,its called "Brain science"