Rusty Gas Tank

mason123h · Post by **mason123h** » Wed Dec 07, 2011 7:04 pm

I picked up a CA77 and am in the process of working on it, and turns out the gas tank is completely coated in rust. I put a bunch of pebbles in it and have be shaking it, but after a while no significant progress has been made.
I was wondering if there was some kind of solution that I could come up with to flush the tank with or any other ideas that I could use to solve this problem.

Thanks for the help!

cleg · Post by **cleg** » Wed Dec 07, 2011 7:22 pm

There are several methods of rust removal. Electrolysis, the works toilet bowel cleaner, vinegar, coca cola, etc. I personally have used vinegar and it really cleans the rust but leaves the interior surface prone to flash rust. If you use the vinegar or any acid means of rust removal, you should immediately refill your tank with gas and keep it full to prevent rust.

brewsky · Post by **brewsky** » Wed Dec 07, 2011 7:24 pm

Here is a pretty good summary of your choices:
http://www.mopedarmy.com/wiki/Removing_ ... a_gas_tank
I ended up taking mine to a local radiator shop and they dipped it in something (they weren't sure what it was?) and cleaned it out very well.

68Cb77 · Post by **68Cb77** » Wed Dec 07, 2011 11:24 pm

POR-15 in mine, worked great. I think the general consensus is Kreem is not so great

Snakeoil · Post by **Snakeoil** » Thu Dec 08, 2011 10:44 am

Cannot speak to modern day Kreem. Kreem was the standard for years. Unfortunately, that original formula was not resistant to ethanol. Ethanol turns the old Kreem into goo. I know first hand because I have a friend with restore Knucklehead that learned the hard way when the balance tube between the two tanks plugged. He stuck a screwdriver down into his tank and pulled out a glob of what looked like silly putty. Which reminds me I have to ask him how he got it out.

They may have fixed their formula by now.

POR-15 is tough stuff. But it is very reliant on the prep prior to coating. And because it is tough, the last thing you want is to have it stick to some places and not others. So make sure you take the time to prep it correctly.

Caswell's tank sealer is a phenolic based epoxy. I used it on an S90 tank. The stuff works well, but is difficult to work with. It is the preferred product to use on fiberglass tanks. The problem is it is extremely viscous and you want to use it on a hot day. But high temps shortens the cure time. I did mine in the basement during the winter and it took forever to cure. If I had known that I would have taken a different approach to how I did it. Too late now. Tank is sealed but I'll bet the sealer is a half inch thick in the bottom.

Again, prep is the secret. Dirty, contaminated base surface will compromise the sealing quality.

By the way, according to a guy I know that makes a living restoring bikes, mostly Brit bikes, the Kreem tank cleaner is the best out there. He uses their cleaner to prep the tank and then seals with either Caswell or POR15.

regards,
Rob

mason123h · Post by **mason123h** » Thu Dec 08, 2011 5:46 pm

Thanks for the help. It think I will try the toilet bowel cleaner for a quick fix.
Any suggestions on how to apply/make it work?

CliffC · Post by **CliffC** » Thu Dec 08, 2011 5:56 pm

I'm just wondering how a discussion on fuel tanks turned up on the Ignition part of the forum and not on the fuel subject. This does not help people using the forum. Cliff