What do you use to clean rusty tanks?

[fordop87]

What is the best solution to clean the inside of a rusty tank?

I bought a CB450 that had been sitting for probably 8-9 years and the inside was pretty rusty. I bought a gallon jug of Evapo-Rust and started soaking the tank while rotating the tank every few hours to soak all sides of inside. After about 16hrs of soaking i poured the Evapo-Rust out (nice and brown!) and then rinsed it out with water and then with gas. It looked good! I was pretty impressed. I probably should have let it soak a full 24hrs.

So what do you guys use?

[DaveMinella]

POR-15 Tank Kit.

[SONICJK]

A 5 dollar jug of muriatic acid.
1/2 acid 1/2 water and it will be rust free in 10 minutes.

Just make sure to remove the Petcock.

[Hoosier Daddy]

"The Works" toliet cleaner...
(see the $50 mod thread)

[ProSimex]

jug of vinegar and a hand full of BBs.

[SpeedBump]

This stuff at full concentration made my tank look like new

[axeugene27]

I use squirrel urine. I collect it over a few months from the local rodents. I then take the tank to the highest point in the county, start a fire and wait for lightning to strike the tank. I then shake acorns around in it for 8 minutes rinse it with baby deer tears and it's good to go

[fordop87]

jug of vinegar and a hand full of BBs.

I like the BB's idea. I didn't even think about that to knock the loose stuff out. So vinegar works that good?

[fordop87]

Found this site that shows several different methods (including some that you guys mentioned already).

http://www.mopedarmy.com/wiki/Removing_rust_from_a_gas_tank

[SONICJK]

Just about any acid will get rid of the rust.

Vinegar is acetic acid

Muriatic is 35% hydrochloric acid

"the Works" is pretty dilute hydrochloric acid

Naval jelly is phosphoric acid.

Pick your poison any of them will do.
You'll quicken the process with some sort of abrasive (bbs are okay but just toss drywall screws in there, they are way sharper, how is a round bb going to scrape your tank? The banging action would help but scratching is better)

I just like HCl because it's quick and easy.

[fitbmxseries1]

Muratic acid and a pressure washer, then spray and roll around some of this stuff http://www.ppcbest.com/phix_treatment.htm. If i line it ill use Norther tank liner. I do 2-3 tanks a week at work.

[Hoosier Daddy]

Believe it or not, I read feed grade Molasses works well if you got time to let it set for a week.

[SONICJK]

You can just dump 3 gallons of coca cola in they and it will do the trick.

[djelliott]

Milkstone Remover. You can get it at Tractor Supply Co. Dilute it to about 8-1. You can do a couple tanks with one mixture. Just dump it from one to the other. After that line it with a Caswell Kit. That shit is amazing.

[ProSimex]

I happened to have BBs handy, my drywall screw supply was all dried up.