Rust spots in tank

[bwringer]

This is almost exactly how I cleaned my son's GS500 tank and it came out great. A gallon should be enough for most tanks. I let it soak for 24 hrs in each position.

-A couple of bottles of 91% rubbing alcohol (supermarket or pharmacy) can be used in place of denatured. The alcohol draws the water out of the seams and absorbs it. NOTE: contact with alcohol didn't affect the oem paint at all but your results may vary.
-If you use the gas cap to seal the filler you may want to disassemble and clean/oil any latching/locking mechanism because the dried Evaporust could cause problems. The GS cap dripped a little when the tank was inverted so I laid it across a plastic tub to catch the liquid.
-I removed the petc0ck and made a plate to block off the opening. It may not harm the petc0ck but I wasn't taking a chance.
-Due to the shape, the GS500 tank was impossible to completely drain thru the outlet. I propped it up so the liquid (water, then alcohol) collected in a corner, inserted a length of 3/16" ID flexible tubing thru the filler into the liquid and blew compressed air across the end (venturi effect) to suck it out. Worked like a charm. A piece of wire can be inserted into the tubing to make it more rigid.
-I would suggest immediately installing and filling the tank to avoid new corrosion.

Evapo-Rust gets kinda gooey when it dries out, which can cause problems. It's a lot like the dried crusty dish soap on the bottle next to your sink. So be aware of that. It won't really hurt anything, but you have to remove it.

Also, you can seal the filler opening pretty well with Gorilla Tape duct tape. I did this back before I heard of Evapo-Rust, and it held up fine against a tank full of water and phosphoric acid. (Which didn't really work... )

[Clint]

Fill the tank with vinager, let it sit overnight. Poor out the vinager and rinse with alchohol. Good to go, no paint damage or hazardous wast to dispose of.

[bob101770]

I tried the 2,000 bb metod and it looked like it worked great but what I did'nt see was that the seam on the bottom of the tank. It can't be cleaned. Rust will come back and screw up the carbs it's only a matter of time. Red-Kote is the way to go. You can do it yourself, or get a radatior shop and drop $75.00

[DaveDanger]

rust cleaning methods

I've tried a variety of these suggestions and most of them do work in some fashion. BB's even work, they simply take longer than something with sharp edges. I found that square nuts of any small or medium size work fantastically. They have good sharp corners to chip rust with, and they're easy to pull out with a magnet if they get wedged in a crevice. A short length (2 or 3 ft of cheap hardware tore chain, the rougher the better) works great also, easier to pull out.
Penetrating oils, Naval Jelly®, converting acids, even water works well to help slide the nuts around and helps flush the crap out of the tank. One of the best results I got with a tank de-rusting using this procedure was using the square nuts and nearly scalding hot water. The exact liquid and sharp cornered objects aren't critical, just shake it till your arms nearly fall off. Flush it till nothing else comes out. THEN DRY IT THOROUGHLY. I like to place the tank upside down on a cushioned surface, and lay or direct a high wattage light onto the tank tunnel. leave it till the heat evaporates all hint of water if any was used. Upside down, the water drains better out of the welded seams at the base of the tank. I heat the tank overnight when I do this step.
If the rust was light to begin with, spray the interior with a good protective oil after you've beaten the rust out, untill you're able to fill it with fuel. Believe it or not, these tanks leave the factory with no sealing of any sort inside them. If kept fueled, they typically don't have rust problems. If the rust was heavier to begin with, then do by all means use a sloshing compound after the crud has been flushed out. I highly recommend the POR-15. It's phenomenal stuff. It is preferred to do it before painting, but I did my own tank most recently after my tank had already been painted. I simpy was more careful with all my steps. It worked beautifully. I can vouch for the POR-15 sealing pinholes.
An additional hint... To avoid using (and maybe damaging) my fuel cap, I went to Home Depot and bought a simple rubber plumbers plug that was barely smaller than my fuel filler opening. They come in a wide variety of diameters. I inserted it in the tank, tightened the wing-nut until the rubber plug swelled and sealed the opening. Worked great. Cost about $3.00.
I took out the oval shaped plate with the fuel petcock and shutoff valve, and temporarily replaced it with a shaped piece of thick sheet metal drilled to fit the 2 screw holes and a piece of cheap gasket paper.
Knock the rust loose, rinse it thoroughly, protect it with oil, fuel or slosh it, reinstall it and ride

[gsgeezer]

I take the tanks on my old bikes to a radiator shop owner, who blasts the inside, then applies a strong epoxy coating, after thorough prep.
Total cost: $60. Well worth it; he does it on "show" bikes and dirt bikes, and it's permanent. (The tank is also masked off so it won't be damaged.)

[bwringer]

I take the tanks on my old bikes to a radiator shop owner, who blasts the inside, then applies a strong epoxy coating, after thorough prep.
Total cost: $60. Well worth it; he does it on "show" bikes and dirt bikes, and it's permanent. (The tank is also masked off so it won't be damaged.)

Where is this shop?

Most I've heard of tell you the paint will be destroyed and charge a lot more.

$60 and no paint damage is a fantastic deal.

[maro]

ditto on where is this shop? I live in SE PA as well....

[Nessism]

Caveat emptor for anyone taking their tank to a radiator shop. Unless you have personally seen the work, you are rolling dice.

[Gargoyle081]

I used the tank sealer that is sold by Casewell Plating...Its a 2 part epoxy that is supposed to be impervious to fuel. The best part about the stuff is that you only have to get the loose rust out of there so your arms are quite as worn out afterwards. My tank wasnt that bad so it was an easy job. The stuff is actually designed to bond to and encapsulate light surface rust. I think the kit was 40 bucks and it was pretty easy to do.Dont think it would ever come off paint once it hardened but you could easily wipe it up if you noticed it within a reasonable length of time. I dripped some on my concrete garage floor and that stuff is no joke. I sealed my tank about a year ago. The only downfall is visual(because the Phenol Novalac epoxy is clear). When I look into my tank I can see small specks of rust on the top of the hump that look like they are covered by smooth clear glass....Just an option to look into though

[Nessism]

I did my 550E tank with Caswell epoxy. It's quite thick so it would be the ticket for a tank with holes in it. Good stuff but maybe overkill for a tank with light surface rust where Por-15 is all you need.

[gsgeezer]

The rad shop is in Reading, PA. I have a friend that owns a small car dealership (who also collects bikes) next door. I take him the tanks and he drops them off for me.
I'm pretty sure the guy does work on a retail basis, I may get a better price because of my friend at the car lot. I have used his service for a number of years.

He does work on tanks that have already been painted; I like to tank my tanks in there before they are painted. I had my GS tank done about a year ago. It wasn't even rusty, but I figured better do it anyway!

If anybody local needs a tank done, I can check it out for you. (Just PM me.)
This isn't exactly an uncommon thing for rads shop to do. Especially shops that deal with custom bikes and antique cars, where there is no replacement.
As mentioned above, try to find an example if their work, or a referral from a satisfied customer, before you take your tank to a local place.