Fixing Rusted Out Gas Tank

[rustybronco]

Bought a Skunk tank as a project knowing it would need some paint work and a failing liner removed. Stripping the outside reveled epoxy patches on the bottom and holes though the metal. Been trying to patch them up by brazing but it's really frustrating - every time one hole is filled another shows up. Had to fashion two patches (so far) because as soon as the torch warmed the metal the holes expanded.

Have to get this thing fluid tight before attempting to strip the liner out and then derust. I'm almost positive that this think is going to spring more leaks as soon as that process begins.

I've never messed around with solder before but wondering if I should tin the bottom front area where all the leaks are.

Any words of wisdom?

Ed, let me do a little test on my old 78 tank which is rusted through sometime tomorrow afternoon and see if the silver brazing rod I have will fill those gaps in on the thin metal without to much trouble. if that doesn't work then the only thing I can think of is to bash it down, cover the area with thin sheet stock, then flux and solder the patch in.

Posting up some pictures of the bad areas might help some as well.

[Nessism]

Thanks for the input guys.

Right now the tank is almost all sealed, just one small pin hole remaining (I think). There are two patches and a bunch of brass filler globbed on. The problem is when the brass goes on, the brazing heat is causing the inside liner to burn and outgas though the molten brass puddle thus causing pin holes.

Dale, I have some silver and will try that next. Silver melts at a much lower temperature than brass so hopefully, I can get a skin over the area so that the de-lining process can begin.

Wish me luck.

[rustybronco]

Ed, this is the type of material I was speaking of. If this is what you are thinking of using, then you and I are on the same wave length.

http://www.grainger.com/Grainger/HARRIS-Brazing-Alloy-Rod-3THF8?gclid=CIjWp52z2bICFStgMgodx2QAog&cm_mmc=PPC:GooglePLA-_-Welding-_-Supplies-_-3THF8&ci_src=17588969&ci_sku=3THF8&ef_id=ZtROmMp5HQMAAIUF:20120928231322:s

[Badooka]

Any reason you couldn't cut the bad panels out and re skin? Tack weld new skin, grind and fill that? Sounds like a tedious endeavor.

[Nessism]

Ed, this is the type of material I was speaking of. If this is what you are thinking of using, then you and I are on the same wave length.

http://www.grainger.com/Grainger/HAR...120928231322:s

Hi Dale,

I have a couple different silver alloy brazing rods: one is high liquidity 45% silver with cadmium (great stuff), and another...I forget, but it flows less.

I'll post up some photos later today.

[Badooka]

This may be exactly what you need, it's a liquid steel epoxy that flows and will do just what you want and not have to worry about the burn through issues.
Item number is 10210. 100% permanent and solvent proof and titanium based.

http://www.brownells.com/.aspx/sid=13899/pid=5808/Product/EPOXY-METALS?mc_id=80000&srch=1&gdftrk=gdfV21820_a_7c187_a_7c3466_a_7c262100101_d_262100101_d_11415

[Nessism]

So, flowed some silver over the repair area and it seem like a good fix. Put some paint stripper in the tank to break down the liner and the tank has four leaks. Small ones at least, and in different areas than I'd been working. Will rinse out the tank with mineral spirits and braze the holes closed after the current batch of stripper runs out of gas. I don't want to use epoxy on the holes since the chemicals will just eat though it.

The liner looks like Redkote, which supposedly breaks down with MEK, Acetone, and paint stripper. Wanted to use MEK but the California ninny government seems to have outlawed the stuff. That's the way CA rolls; they over regulation everything and have one of the highest unemployment rate in the country.

[Charlie G]

I to have a skunk tank I'd like to repair the leaks on. I'm with you on not wanting to use non metalic, epoxy based solution. I plan on trying a non-flame based soldering technique I use on sheetmetal flashings and pans I make. The liner in my tank is a cream or white color. Any tips on what it might be or how to remove?

cg

[Nessism]

I to have a skunk tank I'd like to repair the leaks on. I'm with you on not wanting to use non metalic, epoxy based solution. I plan on trying a non-flame based soldering technique I use on sheetmetal flashings and pans I make. The liner in my tank is a cream or white color. Any tips on what it might be or how to remove?

cg

White liner means Kreem. MEK or paint stripper will take it out.

[Badooka]

That's the same stuff different name we use on F-4 fuel leaks and it held at mach 2- quite sure it would deal with gas on a bike at a 100mph.

[Nessism]

That's the same stuff different name we use on F-4 fuel leaks and it held at mach 2- quite sure it would deal with gas on a bike at a 100mph.

As already mentioned, the tank MUST be fluid tight since I'm using paint stripper and acetone to strip out the old liner. I don't trust epoxy to hold up to these chemicals.

[Charlie G]

White liner means Kreem. MEK or paint stripper will take it out.

Thanks Ed.

cg

[Badooka]

I trusted this stuff- with my life. MEK is a good solvent but there are better. Citrus based strippers are less caustic and equally effective. Give it a try and you won't be disappointed.

[Nessism]

Currently working on stripping out the Red Kote liner. Tried paint stripper first and it softened the liner, but didn't remove that much. Trialed a few liner chunks in acetone and they desolve pretty fast so that's what's in the tank now, along with aquarium rocks. Still have a few leaks, but patched over them with duct tape for now. After I get the liner out I'll have another go at brazing them closed before derusting. Bought some phosphoric acid solution and will use that after the liner is all gone. Hopefully the tank won't spring too many leaks while derusting.

[hampshirehog]

Ed one thing I have always done after using acetone in tank (well, cellulose thinners - pretty similar stuff if not exactly the same) is to wash the tank out afterwards with washing powder. You probably call it laundry powder - the stuff the missus throws in a machine that washes clothes. Followed by a really good rinse with water. That powder eats anything organic (in the chemistry sense) so the idea is that if any acetone has reacted with something inside your tank and formed a new compound it should be neutralised so that it can't break down with ethanol. It's probably not essential but I just feel safer that way.