Best way to clean inside of a gas tank?

Give it a few weeks to harden.

 

Oh heck no. My paint is JACKED.

 

Yes. Metal Rescue works.

Before putting your tank in the dryer, put it in a sleeping bag. Pack the dryer with pillows. Paint will be fine. I used resin rust cutting media from Harbor Freight.

 

Sure does. Skipped the dryer -- I was afraid because I'm clumsy. Here's a soak for about 12 hours. One half 6 hours, the other 6 hours.

 

Vinegar and let it sit for 3 days. Looks like new and doesn't cost much. Rinse with baking soda and water after (to neutralize the acid), then blow dry the heck out of if.
Best thing is that you can reuse it. Just make sure you remove the petcock (or use old one) and close the tank, the fumes eat paint.

 

I'm a huge fan of metal rescue. It's fast (one hour takes you down to bare metal), odourless, hand friendly, and reusable (which is good as it's kind costy at $30cdn/jug, but you only need one).

Vinegar works too, but takes several days and smells

Dryer tumbles work well, but are only necessary if you've got other stuff than rust in your tank. If it's just rust, then dumping in a jug of metal rescue, and rotating the tank every hour will leave you with a nice clean tank in no time.

Object will end up very dull grey and can discolor to black if you leave it in the metal rescue for a really long time - days - but cleans up fine with Scotch Brite.

 

I thought I would show you how I did it. With Arm and Hammer cloth washing mix and a battery charger. Any of these videos will show you how to do it. Takes a while but works really well.

https://www.youtube.com/results?search_query=motorcycle+gas+tank+electrolysis+

 

Electrolysis may lead to hydrogen embrittlement.

Maybe it's nothing to worry about, but I err on the side of caution.

 

+1 Metal Rescue!

 

I went to Wal-Mart and I bought a quart of "Rust-Oleum Rust Dissolver". I'm going to use it for the first time tonight to get rust out of the inside of my tank. I'll post before and after picts and let you guys know what the results are like. If you guys want to read about the product and give me some advice on it, you can learn by finding it on Rust-Oleum's website and browsing through the automotive section.

I really hope it works!

 

I found through trial and error that a few handfuls steel nuts or
screws, or both, combined with phosphoric acid worked the best for me. I dumped a 1/2 gallon of p.a. along with the nuts etc., plugged the fill and petcock holes and shook and rotated the tank for a 1/2 hour.
let it sit for a while and shook it again. I repeated that for about two hours then drained the p.a. ( using a large funnel ) back into the plastic jug that it came in. I then rinsed it out with 3 changes of clear water, shaking continuously and drained it. All the nuts etc. were easy to remove with a magnet on a flex shaft. The tank was then
clear enough of rust to use the Caswells tank liner ( after drying
the inside with a dry heat gun). I would never assume that a 35 +
year old tank has no pinholes, so I always use Caswells as a last step before prime and paint. Also ( very important ) be sure to use a
2k clear coat like Spray max gloss to protect against gas which will
bubble the paint.

 

I second this! Worked like a charm. I pulled the tank off and covered all the holes, including the gas cap, with Gorilla Tape. It held up great against the Cider vinegar. I filled it up with the full 13L and left almost no air gap. I propped the low end of the tank up with some lumber. I let it stand 48 hours. Then dumped onto the rocks beside my house. Magic!

 

I started out using vinegar and soon switched over to a product made for rust removal. The products that are made for removing rust really work well and I think do a better job. Remember to put something in the tank after you rinse it to keep the flash rust from coming back.

If you are going to do a job to it right and I think vinegar is not the choice to make for getting rust out of a tank. I started out that way too, so just trying to save you a step.

 

I found acetone was good at absorbing the last remaining water.

 

runs from 11 to 29$