How-To: Restoring a Rusty Motorcycle Tank

The method I used is crude, but it worked:

Remove the petcock and plug the hole.

Fill the tank with Purple Power Rust Remover.

Plug the gas cap hole with something to avoid damaging the rubber gasket on the gas cap; I recommend removing the gas gap altogether. Make sure it doesn't leak or acid will spill out on to your paint. If you want to be really careful you can mask the entire tank off with painter's tape.

Slosh it around, and let it sit for a while. If the inside is particularly horrible fill the tank with bbs and shake it around for a while before filling it up. Take the bbs out before filling it up.

Drain the Purple Power and rinse the tank with gasoline. The Purple Power leaves a "protective" residue that is soluble in gasoline. If you do not rinse the tank the residue will accumulate in your carbs. An inline fuel filter will NOT stop the residue.

This is what I did and my tank (and my friend's Honda) is/are both rust free after 1.5 years. I do, however, keep the bike in the garage and it never sees rain. It is fairly humid where I live. I do not make any effort to keep the tank full either.
 
bcware said:
The method I used is crude, but it worked:

Remove the petcock and plug the hole.

Fill the tank with Purple Power Rust Remover.

Plug the gas cap hole with something to avoid damaging the rubber gasket on the gas cap; I recommend removing the gas gap altogether. Make sure it doesn't leak or acid will spill out on to your paint. If you want to be really careful you can mask the entire tank off with painter's tape.

Slosh it around, and let it sit for a while. If the inside is particularly horrible fill the tank with bbs and shake it around for a while before filling it up. Take the bbs out before filling it up.

Drain the Purple Power and rinse the tank with gasoline. The Purple Power leaves a "protective" residue that is soluble in gasoline. If you do not rinse the tank the residue will accumulate in your carbs. An inline fuel filter will NOT stop the residue.

This is what I did and my tank (and my friend's Honda) is/are both rust free after 1.5 years. I do, however, keep the bike in the garage and it never sees rain. It is fairly humid where I live. I do not make any effort to keep the tank full either.
Click to expand...

I'll have to give Purple Power a try one day.
 
It was the only thing available to me locally that fit the bill; it comes in a liter-sized bottle and has the consistency of water. Everything else I could find was a jelly.

My friend's cb360 had a nasty tank to begin with and he's been problem-free for 2 seasons so far. We both installed in-line fuel filters though.

I also filled a plastic cup with the stuff on my work bench (it doesn't seem to vaporize appreciably) and soaked all of the rusty nuts and bolts in it. The Purple Power and a brass brush cleaned up all but the most heavily corroded pieces. The pieces I couldn't bring back were literally missing chunks of metal because the rust was so bad.

It is also important to note that with ANY strong acid exposure to metal, especially aluminum, should be limited to something like 20 minutes. Strong acids will dissolve metals if left in contact long enough. Don't soak anything overnight!
 
You can get some stuff called Prep and Etch at Home depot . Its mild phosphoric acid and my be the same as the Purple Power if you cant find that product . Sounds like it . The directions bcware applies to this stuff too . Not very expensive and goes a long ways .

If its REALLY REALLY nasty you can use muriatic acid , also available at Home Depot , but BE CAREFUL !!! or you can blind yourself . That stuff is potent and I don't really recommend it !!! If its rusted that bad you probably have pinholes in the tank after its clean .

clunkerbob
 
A second vote here for Prep & Etch.

On the couple of tanks that I've cleaned, I first used electrolysis to first get rid of all the flaking rust. It takes several days, but the reuslts are simply amazing. A cheap source for sodium carbonate is the stuff pool supply stores sell for increasing Ph.

After the electrolysis has done the "heavy" work, the tank is very susceptible to flash rust. I've found that Prep & Etch will removed this rust and will leave behind a somewhat rust resistant coating. I think phosphoric acid is one of the ingredients in in metal blackening solutions.

David
 
Just cleaned the tank on my other ride - a XJ600 S Diversion. This is really easy.
full
 
For plugging the filler hole whle performing any body work/cleaning/painting work on a tank I use a rubber plug intended for plugging swimming pool water lines. They are available in a variety of sizes and include a screw mechanism that expands the plug to ensure a tight fit. Best part is they are only a few bucks.
 

Similar threads

CaptChrome
81 XS400H – putting the Trusty back into Rusty
5 6 7
Replies
121
Views
17K
CaptChrome
CaptChrome
T
Gas tank cleaning
Replies
6
Views
935
Specdog
Specdog
Echo
'82 XS400R Seca refurbishment thread
Replies
17
Views
2K
buztabuzt
buztabuzt
T
For Sale - 1979 XS400F For Sale
Replies
0
Views
498
tosaxs400
T
A
Free - Very rusty tank, pay shipping and it's yours
Replies
0
Views
687
AlexH
A
Back
Top