Removing POR from a fuel tank.

I have done a couple tanks with POR with good results in the past. However, I guess I rushed my latest attempt and it is flaking and peeling off around the filler hole and under the top. Using the advice from a friend, I tried to remove it with drywall screws and gave it a good spin in the dryer yesterday while the wife was at work. After several hours, nothing looks any different other than needing to clean up the dryer. (not really, I had the tank sealed, and wrapped in a couple trash bags) ;-)

My thought was to at least get the loose flakes out and encapsule them with Caswell tank sealer, but if I'm not making any progress with mechanical removal. Reading Caswell's instructions, they say , "When recoating your gas tank from failed Kreem or POR-15 tank sealers, remove the old, failed coating using a paint stripper containing Methylene Chloride."

However, Methylene Chloride isn't available to the public, and is apperently really hazardous to your health, safety, and the enviroment. Caswell sells it, but only to licensed users. Actually, I might be able to get some, but don't want to try without adult supervision and advise from someone who has used it and can tell me if it really worked.

Alternatively, does anyone have a recommendation for a business that can remove and reline this tank. BTW, it's an Interstate tank, the baffle makes it real hard to see what's going on the the back of the tank.

TIA

Why not clean up as best you can, removing any loose bits etc, then re-prep exposed metal and put in a another layer of POR to seal the poorly prepp'd areas?

2 + hours of rotating around in the dryer with sharp objects did nothing to remove any of the peeling POR. Grabbing the loose ends at the filler cap with a pair of needlenose pliers resulted in just breaking off tiny bits, leaving plenty left stuck. Then there's how to reach the loose stuff behind the baffle...

I believe POR relies on rust to adhere to metal, as part of the prep, flash rust after rinsing is desirable. I doubt a second coat would adhere to the first coat.

norton73 said:

2 + hours of rotating around in the dryer with sharp objects did nothing to remove any of the peeling POR. Grabbing the loose ends at the filler cap with a pair of needlenose pliers resulted in just breaking off tiny bits, leaving plenty left stuck. Then there's how to reach the loose stuff behind the baffle...

I believe POR relies on rust to adhere to metal, as part of the prep, flash rust after rinsing is desirable. I doubt a second coat would adhere to the first coat.

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POR 15 is a moisture cured epoxy that usually sticks like shit to a blanket.
M.E.K ( Methyl ethyl ketone) unless already mentioned is a good cleaning solvent and easy to get.

norton73 said:

2 + hours of rotating around in the dryer with sharp objects did nothing to remove any of the peeling POR. Grabbing the loose ends at the filler cap with a pair of needlenose pliers resulted in just breaking off tiny bits, leaving plenty left stuck. Then there's how to reach the loose stuff behind the baffle...

I believe POR relies on rust to adhere to metal, as part of the prep, flash rust after rinsing is desirable. I doubt a second coat would adhere to the first coat.

Click to expand...

According to their website FAQ, although it can bond well to rust, it can also be topcoated/painted.

It appears to be epoxy based and epoxies are generally very good at secondary adhesion coats. Best to have some surface scoring to improve interlocking of new coat.
Can't see it making things worse, you still have the option to hit it with solvents to remove if that is your ultimate decision.

Hows the paint?

Way back when you could take tanks to a radiator shop and have them dipped to strip them bare. Don't know if they do that any longer.

gortnipper said:

Hows the paint?

Way back when you could take tanks to a radiator shop and have them dipped to strip them bare. Don't know if they do that any longer.

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I took my tank to a radiator shop and they did just that plus they sealed it and primed the outside. I think I paid $120.00

The paint is decent. I've done that in the past with a tank I was going to have painted. Dipping it will be a last resort.

Update.

As per the instructions from my buddy has done several tanks with Caswell, but not to cover POR, after tumbling the tank and rinsing it with water, I put a 6% mix of white vinegar in the tank to fill it. The POR has started to lift where it was loose. Sitting out in the Alabama sun, it has heated up a few times, almost too hot to touch. Maybe after sitting like this a while, I will try to tumble it again and see if if enough loose stuff comes out to encapsulate the POR with Caswell.

I have the same situation, but unsure what the coating is. I happen to have some methylene chloride, but think that (or any other solvent) will just make a big mess inside the tank that i won't be able to fully clean out. My plan is to mechanically scrape as best i can (albeit not in a dryer) and then try to pressure wash as best i can (3/4 of the tank seems inaccessible). Then use a good rust preventer (fluid film?) and fill er with gas. I'll probably need an additional in-line filter and have to regularly clean the filters, but think that's better than possibly making the situation worse in the tank.

At least that's my plan

TomU said:

I have the same situation, but unsure what the coating is. I happen to have some methylene chloride, but think that (or any other solvent) will just make a big mess inside the tank that i won't be able to fully clean out. My plan is to mechanically scrape as best i can (albeit not in a dryer) and then try to pressure wash as best i can (3/4 of the tank seems inaccessible). Then use a good rust preventer (fluid film?) and fill er with gas. I'll probably need an additional in-line filter and have to regularly clean the filters, but think that's better than possibly making the situation worse in the tank.

At least that's my plan

Click to expand...

Fluid Film is for undercoating cars and putting on panels. It does not set/harden and remains basically like a layer of oily wax. It will not resist gasoline so will be useless inside a tank.

If you are trying to remove existing rust, then a converter like EvapoRust, MetalRescue or even cleaner strength vinegar will work nicely.

Anyone know what modern bikes use as tank sealers? Guess whatever they use, they are applied on new uncontaminated metal, not like our situation.

I used methylene chloride to remove Kreem sealer. .Fill tank as much as possible and let sit for 12 to 24 hours. Then rotate tank to allow solvent to wet remainder of tank inner surface and let sit again. Rinse and shake or tumble with drywall screws.
Be prepared to ruin tank's paint job.

Commercial paint stripper is 40% methylene chloride.

Slick

Frost Restoration Supplies in the UK sell a product called Tank Strip. It's basically a good old fashioned paint stripper & works on POR 15. I've used it to strip a frame of powder coat & it works well.

Martyn.

"However, Methylene Chloride isn't available to the public, and is apperently really hazardous to your health, safety, and the enviroment."

I worked with for a while in the eighties. The dangers were not as widely know/accepted/safeguarded.