Aluminum gas tank; way of purification?

[hartattack]

Hi, I know that this forum is only for mx bikes but my dad has a
1974 Suzuki RL 250 trials bike. It has an aluminum gas tank.
It had a small leak and he used cream gas tank sealer to seal it.
But it still leaks.
Now he found his friend can weld aluminum. So he tried to clean
out the sealer and little bits of dirt, but he can't get it all out.
So my question is what can he use to purify the tank to clean all
the sealer and dirt out? Is there a type of acid? Someone told
me to use muriatic acid? Is this true? Please help. thanks Evan

 

[Camstyn]

If you know this forum is only for MX bikes, why did you post it here?

 

[MXSparx]

Must be the same guy that sits in geography class asking questions about chemistry?
Not positive. Just a guess

 

[demographic]

Heartattack, you could try posting this in the vintage forum cos I would say that a few of them will have alluminium petrol tanks and might be able to help you. Also they might not be quite so bloody pedantic as the last two answers ( you guys have seen new crossers with custom alloy tanks have you :think: )........ Also there is the trials forum here http://dirtrider.net/forums3/forumdisplay.php?s=&forumid=54 Good luck, Mind I used to work as a welder so am thinking why don't you just put a spot of weld over the hole and then just file it down, If it has the sealant stuff on the outside of the hole then just grind it off then use an in line fuel filter to keep the crap out of your carb

 

[Jaybird]

If the welder you know doesn't know how to prep the material for a good weld, then he isn't your man.
Lots of folks claim they "can" weld...but many of these folks have no clue as to how to weld materials properly.
Ask him how he would handle this and you'll know if you should let him weld it. (I would probably grind the bad material away...but that's me)

 

[Ol'89r]

Evan.

Muriatic acid works pretty good for cleaning aluminum. I would go with Jaybirds suggestion of grinding the area on the outside and welding over the hole. BE SURE THAT YOU DE-GAS THE TANK FIRST. Even an older gas tank that has been sitting a while can have enough fumes in it to blow your head off.

I normally use Gunk Super Concentrate to de-gas a tank. Pour the concentrate in the tank and shake it around for about 5 to 10 minutes. Then, drain it out and run water through the tank for at least one hour.

Just my $ .02

 

[Buckholz]

Solvent for Kreeme coatings is MEK, if I remember right. MEK is bad stuff, but is still available.

You must get rid of the Kreeme coating before welding, regardless of the talent of the welder........

 

[Buckholz]

give em a call, they'll tell you how to remove

Kreem is made by "Kreem Products" (P.O. Box 399, Somis CA). Phone number is (805) 386-4470. Information on product container reads: "Kreem Fuel Tank Liner is designed for use as a preventive maintenance product in metal tanks, new and old; containing gasoline, gasohol, or diesel. Kreem Tank Liner has a unique formulation with extremely rapid set-up, that prevents leakage from hairline cracks and seam pinholes by coating the tank's inner surface with a fuel resistant elastomer. Not for plastic tanks. Kreem is NOT compatible with all fiberglass tanks. You must spot test before use."

 

[dell30rb]

I use muratic acid to prep stuff for andonizing. It does a great job of getting rid of grease and oil that may be on the aluminum.