surface rust in tank ?

I went to the file base & looked up rust in tank , & it called for tile & grout cleaner with phosphoriic acid as the main ingredient, Iwent to five diferent stores & none of the labels listed the ingredients...does anyone know what brand of tile & grout cleaner was used in this prosess ?? ....Pete

Here is what I did: Went to the hardware store and bought about 3 pounds of roofing nails. Took the tank off the bike drained all of the fuel and then let it dry out for a day or so. I then carefully poured all of the nails into the tank and spent about 15 minutes rolling the nails around inside by rotating and shaking the tank while holding it. All of the nails came out easily.

The nails scraped the rust off the inside of the tank and then I rinsed it out several times with gasoline. The final step wasn't necessary but I picked up a can of Red Coat tank sealant and poured the one quart bottle into the tank and gave it some more rotating and shaking.

Red Coat stays pliable and never hardens. Total cost less than thirty bucks for the nails and Red Coat (available at any auto parts store) and this is a lot less than the $150 my local rad/tank shop wanted to do the same type of cleaning and sealing.

Cheers-Colin Firth-Ontario Canada

I know home depot sells phosphoric in the paint section, that's where I got mine, do a 50/50 mix with water. In stead of screws and nails I use a length of chain, it's easier to get out of the tank when you're done. The phosphoric will only attack the rust not the tank.

I know this sounds crazy but I've seen people use Coke to clean surface rust from tanks. The Phosphoric Acid in it will dissolve the rust without removing any of the metal. I've also heard of the same thing being done with white vinegar. Just fill the tank with it and let it sit over night and let it work. Since both are cheap it would be worth a try.

I use the BEHR brand Concrete & Masonry Cleaner/Etcher from Home Depot. It works very well.

There's a fellow who was selling a 4 or 5 pound bag of Oxalic Acid. This stuff is supposed to take all the rust out and leave a protective coat. What's nice about this stuff, is it don't harm paint. don't have his address right now. Maybe someone here has an address. I'll get back with it later if no-one pipes up. I'm not on my own computer. Bob

Thanks for all the tips,....I went online and found phosphoric acid cleaner for under 12.00 bucks a qt.at Home Depot,...the local grocery store sells white vinegar for 1.69 a gal. I think I"ll try the vinegar 1st, as I"m worried about getting any acid on my paint job, if it needs something stronger, then I"ll order a 5# pail of oxalic acid online for 22.00...I just have to find out what the dilution ratio is for the oxalic acid....P.S. its for a LTD 900 tank, so I only need 3 1/2 gals. of vinegar, for a little over 5 bucks, ...Thanks again Pete

Remove the. Fuel petcock and the tank cap. Plug with a rubber plug or cork. Buy a small bottle of
muratic acid,the kind meant to add to your swimming pool. Pour in I quart and shake, turn upside down
and side to side for 30 minutes. Flush with a garden hose for 30 minutes. Then pour in 2 pints of isopropyl
alcohol. Shake tank for 5 minutes,this absorbs water. Then pour out. Put a hair dryer nozzle in fuel hole and
turn on high heat all the while insert a hose,compressed air flow in petcock hole to dry inside quickly.

Once dry install petcock and cap,fill with fuel or at this point fill with por15 tank liner. But that is a 96 hour cure time.