Topic: Fuel tank went from a nice metal sheen to a rusted disaster!

[hapsh]

Yes, the acetone absorbs the remaining water droplets and vapor that is still in the tank.  When you pour out the acetone it carries the water with it.  I found 2 applications of acetone worked well.  However, I did not wait until the acetone was completely dry in the tank to add the oil/gas mix.  If you leave the tank open with the oil coating the tank, the remaining acetone will evaporate fairly fast.  One thing to consider is your humidity level in your area.  I did my tank when it was totally clear outside and very low humidity.  If you live in a fairly humid environment it may be better to use the phosphoric acid method.

[Dave-and-his-550]

If you live in a fairly humid environment it may be better to use the phosphoric acid method.

Ya the ground is still wet here, and it has rained the last couple of days...The good news is, I have found the rust converter products that contain phosphoric acid, at Walmart and Orielly's Auto Parts. They are VERY small bottles though, and $4 a piece, I think I'd need like 4 or 5 of them to be able to coat the whole tank, and I've already spent $50 on materials 

I think I'd rather take my chances again with the $1.25 bottle of The Works.

[paulages]

a little 2 stroke oil in some fuel swished around inside will protect it as well.

[Cvillechopper]

Evaporust will get rid of the rust and leave a coating for several weeks that'll keep it from rusting until you're ready to coat.  Just rinse well, dry over night, and coat.  I had absolutely NO rust after the muratic acid bath, Evaporust over night, a week waiting, then rinsing the residual evaporust out, and drying over night.

It's not cheap but it works and you can use it over and over again. 

Good luck.

[Hope]

I am sorry to hear that you have 3 attempts and you're out $50.  You'd be done by now and you wouldn't have spent as much if you would have used POR15.

[dkruitz]

No need to let it fully air dry after rinsing with water, you want to use the acetone or alcohol to get the rest of the water out ASAP.  Letting it sit around to air dry will help cause flash rust.  Use 2-stroke oil, POR15, or fill it with gas to keep it from flashing.  Phosphoric acid from HD worked great on the suzukimatic I helped my brother-in-law with, and a 2nd coating per the instructions helps lay a carbon layer on the metal for protection - seemed to work on his.