Opinions on fuel tank coating?

[JonTheClueless]

Is there a general opinion about using a fuel tank coating (Kreem/Caswell) on a de-rusted tank? Always struck me as sacrilegious or something, would rather let metal be metal. What do other forum folks think?

[matt glascock]

I've had consistently good results with Caswell 2-part epoxy tank liner. Be absolutely detail-oriented and precise with all instructions.

[dirty_rat]

Unless the tank is leaking out of a seam or pin holes, I would stay away from linings. Some people have had luck with them, but those that haven't have had all kinds of nightmares with trying to fix it afterward.
If all you had was some rust inside and you have taken care of it, and it all appears sound, I wouldn't line it. For a tank I wasn't going to use for a while, I have treated the inside with something like "A Must For Rust", (available at most hardware stores), which treats the metal so it is somewhat rust proof.

[JonTheClueless]

I have treated the inside with something like "A Must For Rust", (available at most hardware stores), which treats the metal so it is somewhat rust proof.

May I ask If electrolysis is an option on the tank interior without causing issues with the exterior chrome of the tank? Or is chemistry the best way to go, do you know? Must have watched 10 videos on de-rusting a tank, lost count of the number of web pages on it, added to buddy opinions - which are all over the map.

Maybe like you, I would really prefer to not coat the inside tank at all. There are no pin holes; the tank still even has a minor amount of old gas/oil mix still in it, zero leaks. Nothing against you Matt!

Thanks!

[MTrat]

I've used electrolysis, chemicals and agitation. I usually prefer mechanical shaking with pea gravel and water with frequent rinses, then vinegar to get out last rust. Rinse and quick drying followed immediately with gas/oil coating. Use tank liners only as a last resort.

[viclioce]

I use Muriatic Acid for tanks which are dirty/rusty inside. But it’s not an easy treatment to do. You must stay with the tank, agitate frequently and keep inspecting for completion. You also need to know if the tank has rust pitting which goes all the way through. If it does, you’ll get pinhole leaks.

Vinegar can work if you need to let it sit over night. And, as with all acid treatments, cleaners, you need to neutralize the acid with baking soda water to halt the process and neutralize quickly. Then you need to blow dry & coat the inside of the tank with oil/fuel to prevent flash rust.

I have seen a few folks eat right through a tank because they either didn’t dilute the Muriatic Acid enough or they just left any type of acid in the tank for too long. They ended up with a chrome plated sprinkler attachment! Victor

[dirty_rat]

I have used electrolysis before and it worked very well. I did it where you just fill the tank with solution, not where you place the entire tank into solution. Here are the instructions I received for someone, don't remember who:


I'd read about a few of you folks using electrolysis to clean your tanks and now I'm sold! I cleaned the rust fuzz out of my Dirt Squirt tank using the electrolysis method. It cost me about ten bucks and worked great. It took about 24 hours to get all the rust out from the far reaches of the tank.

I made an insulator out of a 2" ABS pipe coupling with a cap on one end. This happens to just fit over the opening of the tanks with the large filler holes. I drilled some holes in the sides to vent the gases and put a threaded rod down through the cap as far in the tank as I could without touching the top of the "tunnel" (make sure the rod is at least 1/2" away from any metal as you don't want it to touch and short out the circuit). Then I propped the tank up on blocks to level it and filled the tank up to the top with a solution of Arm and Hammer washing soda (I think I used about a 1/2 cup of washing soda to 2 gal of water, don't remember exactly now). Connected the ground to one of the petcocks and the positive lead to the threaded rod. Plugged the jumper battery unit in so it stayed charged and waited.

The threaded rod will start to attract the rust within 10 minutes. I cleaned the rod off 4 times in 24 hours just because I thought it might help it go faster and I didn't want it to attract enough rust to come in contact with the tank anywhere (make sure you turn the power off before you try to take the rod out or put it back in, don't want to cause a short. Also, this method produces hydrogen gas so don't do it in an enclosed space, let the gas vent...remember the Hindenburg). The metal nearest the threaded rod was clean in less than 45 minutes.

After 24 hours I put in the obligatory 1/2 cup of misc. nuts and shook them around for a few minutes (I did not do this and my tank came out very clean, so this step is up to you). You can pour out the solution anywhere (it's just laundry soap),although I wouldn't recommend pouring down your drains because it is full of rust flakes and may clog the drain or stain, remove the bolts (easier said than done), and rinse with "Must for Rust" rust inhibitor. Just to be safe, I zip tied a shop rag to a socket extension and wiped down the inside of the tank. Then I removed the petcocks put my shop vac in the filler hole, taped around it, turned the tank upside down and let the vac run for an hour.

[matt glascock]

I made a bad assumption. I would only use the Caswell in the setting of a leak. If its just rust that is the problem/concern, I fill the tank with Evaporust for a few days. Empty. Rinse well with water. Blow it out with an air gun. And coat imediately with premix. It will flash rust quickly after this treatment so get it coated in fuel quickly. Also, this might expose pinhole leaks.. If its not that bad, toss in a handful of drywall screws and give it a good shake to knock out the big flakes, rinse with a little fuel, and leave it alone. ALWAYS use a good in-line fuel filter under all circumstances.

[Darrell]

POR-15 sealer for moderately rusted tanks.

Caswell two-part tank sealer if the tank is like a sieve.

NO Kreem ever!