Best way to clean inside of a gas tank?

Vinegar does not convert the rust. Any acid will clean the rust off, but only phosphoric will prevent it from returning.

(well, Hydroflouric acid will prevent the rust from coming back, but only by making the steel go away as well)

 

It really depends on how heavy the rust is.
~For light surface rust a good soak with white cider vinegar will clean things up nice. Will need a fogging coat after treatment. Great for a winter storage treatment!
~For medium flaky rust a 20% MSR (Milk Stone Remover) soak for approx 8-10 hrs. Will leave a phosphate coating to protect the surface.
~For heavy rust and pin holes. Seal pin holes and soak with 10% Muratic acid (Pool/Concrete Cleaner) to remove the deep embedded rust. Will require a sealer (POR15, Eastwood) after cleaning. Give the Kreme sealer to someone you do not like! They will hate you forever!
~Kreme sealer that has pealed. Only one treatment will work. MEK! Be Very Very CDC Suit careful!! This stuff is extremely nasty!!! Not recommended for home treatment!! You will be repainting afterwards.
~Make sure you flush and neutralize (baking soda) any acid based treatment!
~~ Remember! Acid into water! Not the other way around!

Every type of sealer will require a pretreatment. Eastwood Fast Etch and POR15 Metal Prep work good for this.

Any type of stone, gravel, chain, screw tumble treatment will only work on the surface. It will not work into the porous metal, or seams to remove the hidden rust! Why waste the time and effort??

Gas fumes in a dryer?? Really!!!

~Ghost

 

They look like the guys who told me to put AJAX in my Rice Krispies. Beats the heck out of a Bloody Mary morning!

 

When Chevy first came out with their 283 V-8, they had trouble with oil consumption due to rings not seating properly. The fix was literally to run the engine and pour ajax down the carb throat to scrub the rings and cylinder walls. Go figure.

 

Hello, ABIDE and everyone. I have been lurking for a long time off and on. You all seem like a good bunch of guys. I'm hoping to meet some of you one day. ABIDE, where would one buy Phosphoric Acid? That is your choice of rust remover, correct? And after your tank is treated with phosphoric acid there is no need to coat the tank?

 

Username is k-moe.

Phosphoric acid can be found at any store that carries cleaning supplies, or concrete and stonemasonry supplies (most big-box stores). Many farm supply stores also carry it.

 

K, k-moe. Sorry about the name change. Puter stuff just isn't my cup-o-tea. Thanks for the info. I can't find it now but I thought you wrote somewhere you didn't have to worry about coating the tank after using phosphoric acid. Is that true?

 

I think some folks don't line the tank after acid treatment. After research, I ended up using POR-15, which is a 3 step process. It uses a strong acid to first attack the rust, then after a rinse, a neutralizing solution. After another rinse and dry (involving a hairdryer), the epoxy coating is applied. I noticed there was a lot of flash rusting when I dried the tank. The instructions said, that's OK, the epoxy bonds to that. I've only gone 1200 miles since then and probably 10 fill-ups and it still looks great in there. Not enough time for judgement, so talk to me in a few years.
The point of describing this is that rust may easily appear on freshly cleaned metal. I don't know how that's avoided, so maybe someone else can comment on that.

 

Hi, dkavanagh, I lined a couple tanks years ago. I used some stuff called Metal Etch. It was in a GLASS bottle. My Dad had it and gave it to me. I have no idea why he had it. As soon as you rinsed out the tank the rust began so you hurried and dried it and lined it. The liner is still holding up after nearly 30 years. I thought if the phosphoric treatment didn't need a coating afterwards that would be great.

 

personally i won't buy a bike with a lined tank just because you don't know what's under there.
if you're going to let it set empty for awhile use something like this for the last rinse
http://www.use-enco.com/CGI/INPDFF?PMPAGE=877&PMITEM=411-1164
any machine shop would have a half cup of it to spare, some of it even smells good.
mix it 5 or 10% with water and slosh it around and dump it out

 

FOUND IT! Well, I guess it doesn't say you don't need a liner...

 

I used a Caswell epoxy liner. I don't think anything will take it off once it sets up. Harbor Freight has resin rust busting blocks. Put a couple of pounds of that in the tank before you put it in the dryer. Clean-up is easy and the resin doesn't cut good metal.

 

I've got to where I use the electrolysis method myself. I use distilled water and arm and hammer washing soda. A small battery charger with 2-10 amps is what I use. After I clean it I use Kreem kit to seal it. I've used this method on several tanks on motorcycles and cars and trucks. Xs650.com "rust removal from inside gas tank"

 

Before electrolysis, read this:
https://en.wikipedia.org/wiki/Hydrogen_embrittlement

I have come to believe abrasive, Metal Rescue, or Evapo-Rust are the safest methods.

 

Bringing this back to life as my tank has accumulated some serious rust sitting around since November. Has anyone used Metal Rescue? It's available locally and since I just got a new paint job I'm really not eager to chuck my tank in the dryer or use an acidic solution. Metal Rescue seems to be pretty safe but 1/3 of the reviews online claim it doesn't work.

 

Bell curves. All reviews follow bell curves.

 

So you're saying there's a chance.

 

I used the tumble dry method last night and worked well. Be prepared to have to fish the last few stones out ( I used DumGum on the end of a long flat head). 60 minutes and all the surface rust was gone, flushed with gasoline and fogged it HEAVY with wd40 .

 

Did you have a fresh coat of paint? I'm mostly nervous about dinging the sexy new gloss black.