I'm in the process of Kreeming my bike's gas tank, and while I was acid etching it, low and behold, several pinhole leaks popped up at the aft end of the tank as the rust was eaten away. Being that this is a 1982 bike, I can't just go find a new tank off the shelf. I'd rather not abandon this tank because aside from those 15 pinholes, the tank is in great shape.

I'm trying to solder it, and having SOME success. I clean the area with a dremel tool and then use a butane soldering iron (equivalent to a 120W electric) to apply silver solder to it. Problem is, some of it sticks and I've patched a couple holes very well. Other times it doesn't stick at all and still leaks. I've tried plumbing flux and rosin flux as well, and neither seems to be helping.

I'm thinking I might need a higher power solder gun (300W), but before that I want some extra opinions. Anyone ever do this before? any tips?

 

A 1982.... what kind of bike again?

Check out this method:

http://www.ehow.com/how_2079121_repa...-gas-tank.html

With this sorta stuff:

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

Or do it all with this:

http://www.amazon.com/POR-15-FUEL-TA.../dp/B001NJ6JMK

Por-15 is amazing stuff re: rust. And the description is right: Have a clean tank or it don't work.

I'm thinkin' this might work well for your problems. You can do the soldering to get the pinholes filled, smoothed out, etc, and then seal it with this when you're done. Basically, paint and body the outside, seal the inside, off ya go.

 

I've got an old GMC 2 ton cattle truck that had a gas tank leak. Took the tank to my local radiator shop and they cleaned it, might have soldered some, but mostly put something that looks like a green epoxy coating on the inside of the entire tank. Works great ever since and it wasn't much $$.

 

These are both interesting options. I already have the Kreem Tank liner, and it's Methyl Ethyl Keytone based. The pre-coating rinse is pure MEK. And I subjected some Seal-All to it, which is gas proof sealant, and the MEK desolved it in minutes. I don't know if the epoxy would stand up to it.

 

If the Por-15 stuff is anywhere near the regular Por-15 used on rust... I can pretty much guarantee you the Por-15 stuff will stand up. That stuff is **** near bullet proof, doesn't want to leave whatever it's attached to, and will not be eaten by much. You have to grind it off. And if it gets on you? You will wear it for 3 days.

The only thing that really gets to it is UV. And paint can help that... or the inside of a tank.

http://www.por15.com/faq.asp
http://www.por15.com/HD-CYCLE-TANK-R...ctinfo/HDCTRK/

ooh, check it, they got this too!
http://www.por15.com/CALIPER-PAINTIN...oductinfo/CKB/

I may get that...

/I get no monies from Por-15, but I believe in that stuff very much. I'll stop now, though, I've said enough.

 

instead of soldering, can the holes be welded shut? of course you'd thoroughly flush the flammable junk out first!

 

what about that bed liner paint stuff. Is it less expensive than the por stuff? I would think that stuff would work pretty good

 

Less expensive than $50? There's a 'you get what you pay for' issue I think I'd be having on that... Also, it's not the correct application: You don't see people filling their trunk beds with gasoline, a solvent to many materials, and I would think this might not be long term viable.

 

/\ no dobt just throwing it out there. That stuff is as tough as nails tho.

 

I think a picture is worth a thousand words here:

 

When I accidentally drilled a hole in the gas tank of my wife's Escort while drilling out a broken seat belt bolt, I used JB Weld to repair the hole. It was still holding up fine when we sold the car years later.

 

Never seen pins that big!

Looks like you need to weld a section in. Are there bike junkyards?

 

Well now, I never said what kind of pins they were! They started out as pinholes but the acid treatment opened them up

 

know anyone that has a mig welder? Zip that stuff rat quick 4 shore

 

Ooh, wow. Man... that's gonna be tough. I saw your reply in the other thread, so I understand... Is that the underside? is the top side ok? If so...

Contextually, that picture needs help... but it looks like we're talking the underside of the tank, so....

You should cut out a 'cat's eye' shape of that bad metal and toss it. Then get a piece of flat metal, and weld it in there.

A shop could do that in about 20 minutes. 30 tops. It doesn't even really have to be very pretty, unless you plan taking the tank off and showing it off under there... Just cut enough to get rid of the bad rust holes and weld in a new plate. I'd say that if you had the metal cut out, and then just have a piece that'll weld up right over the hole, not IN it, just over it... and weld the edges good... you wouldn't have to do anything else except, IMO, epoxy seal the thing like above.

You may even be able to just weld a cover plate over the holes, provided the rust is gone, and just epoxy seal it too.

But I don't think you're going to save that holey metal. It's just too... bad.

I don't think it even has to be terribly pretty, overall, just functional. It's on the underside... does it show much?