White coating inside metal gas tank

Well, looking inside the metal gas tank, which has a white thickish coating on the inside, I saw it had large cracks in that coating on the inside. There are no leaks. Along the cracks the coating seems to be curling up away from the metal of the tank. What the heck is it and will it eventually all disintegrate plugging up the tank valves, or worse, the carburetor. Had the carb apart recently. All was perfectly clean.

Sounds like a sealer/coating failure.

Clogging up the carbs is inevitable.

Use the search function to get info on removing. Harsh chemicals such as acetone and MEK are involved ..... most likely will ruin your paint ..... Sorry to bring bad news.

Slick

sounds like its Kreem Tank Sealer. not so good with ethanol. I think MEK removes it. others with experience will chime in here

Thanks for the cold dose of reality. Usually these things respond best to one harsh chemical or another. Of course I plan on being soooo careful, but it's a paint job down the road for sure. Hopefuly the strainers on the taps will start to clog first. And I'm thinkin the tank sealer was probably not put there pre-emptively. I'll find out soon enough. Anybody know how long before it actually begins to disintegrate after it starts cracking?

If you clog the filters in the taps too badly you might starve the.engine and blow it from running too lean.

Anybody have direct experience with this stuff -- whatever it is?

If you decide to remove it, be very careful. Do it outside, not in enclosed area. Avoid fumes of MEk, fumes destroy brain cells, very bad stuff. Bad, Bad, Bad. Even outside be careful not to get your face too close to filler neck. Caswell has a product that is a 2 part epoxy and they "claim" that it is resistant to ethanol. Note that they say "resistant" and not ethanol proof. Use non-ethanol gas whenever possible and don't leave ethanol fuel in tank for any longer than necessary. Good luck. There should be many posts about this. Use the search feature.

Plus 1 with XTINCT.

I do not think you have any choice but to remove it.

It may help to know exactly what it is you have, but most of the fuel tank sealer products yield to MEK and methylene chloride (active ingredient in most paint strippers).

Use the search function!!! Good luck with it.

Slick

If you can get the Kreem or whatever it is out of there and need to reseal due to leakage, The Bill Hirsch motorcycle tank restoration kit comes with a sealer that goes on very thin and should not be prone to peeling. Instructions say to clean, etch and then apply the sealer. You pour it in, swirl it around so it coats everything and then pour it back into the can before it cures. It also comes with some epoxy for plugging leaks before you seal. The Titanic's tank was pretty much swiss cheesed with leaks along the bottom perimeter underneath and on top and other leaks at the frame tunnel and even on the top surface. I had a couple of gallons of premix on hand for the chainsaw and blower and the tank held that for a day with no leakage. Next test will be to fill to the neck to make sure it's totally sealed.

I used acetone to remove the failing Kreem out of my Atlas tank. It completely disolves it. but as other have said, it will completely ruin your pain it you get a drop on it. I managed to spill the acetone all over the tank and had to get it repainted. There is one place near me that can strip and seal it without ruining the tank's paint, so there are probably places that can do it for you.

It's not hard to do, but it's a giant pain in the ass and I will never try to do it myself again.

To those who have used acetone, does anyone have a good set of instructions? I could see having to fill the entire tank or just enough to swirl it around in there. I don't know how much acetone would be needed to disolve all the kreem. Would you have to do it once, then put in a fresh batch and swirl that around some more? Or would one sufficiently large batch do it? How long to let it soak? Lots of questions -- sorry.

I would guess, filling to the neck, closing get the cap, and soaking for 24 to 48 hours should do the trick.

If you try to swirl it, you are sure to get it coming out the filler cap vent hole, or even the cap if it leaks ...... ruined paint.

There is likely to be spotty remnants which you can attempt to remove by placing dry wall screws, or piece of light duty chain in the tank, then shaking untill your arms ache.

If the tank leaks, I would recommend repair by welding or soldering, taking the proper precautions about doing so with a tank that may contain explosive vapors.

I do not recommend using another sealer. Preparation is everything for sealers to be successful. How well prepared is your tank interior going to be after removing the old stuff? There are sure to be traces and spots remaining. Even if you do not see any, will you be sure the nooks where you cannot see are clean?

Slick

Been thinking about what I saw in the tank(Kreme -- or whatever). What follows is admitedly nit-picky and speculative but I really don't know how Kreme deteriorates under immersion in ethanol so I have to ask, when Kreme does deteriorate, does it first crack along large irregular shaped segments(about two inches from crack to crack at widest), curling slightly at the edges, or is that a sign the coating didn't adhere due to a tank preparation problem. "Well, what does it matter?" we all ask. If it's deteriorating due to ethanol it is (from what I've been told) desolving and will show up in filters (the filters on the petcocks and the filter I just added) and in the carb float bowl as a gel to gum up small passages(was just told that's how it appears). But the carb float bowl is perfectly clean like new(which it might be). Now that doesn't mean that when it deteriorates it doesn't first start cracking under ethanol and that's the part I don't know. When I got the bike the tank came in a separate box newly painted, petcock holes plugged up and gas cap taped etc. My guess is the tank was lined when it was painted. So the only gas to hit the liner was one tank from a gas can my son says came from a "no ethanol" station. But I'm not sure about that. The Kreme is still adhering to the tank, just curled up at the edges along the cracks now, but large flakes of Kreme not even broken off yet wont soon make it as particles past the petcock strainers and fuel filter I've added. I'm thinking I've just got to keep an eye on things. Just trying to save myself the trouble of cleaning out the tank with MEK or acetone as Xtinct, Texas Slick and others have pointed out. Even if my brain cells aren't affected (already dead?) by MEK the tank will probably leak and need soldered and sealed up again and then will need repainted. And if I get an old tank in good shape (what would that cost?) it's guaranteed the paint wont match.

I wouldn't be sure that the tank will leak just because somebody lined it. There was a period of time when this was considered a good idea to ensure longevity of the tank. Of course for a long time you couldn't buy one either, so saving old tanks was a big deal. Now Emgo makes what is reported to be a good replica.

I've been through the process of removing sealer from a tank. Mine was brown in color. The process took a long time, lots of chemicals, and eventually I stuffed the tank into a cement mixer wrapped in a moving blanket so that MEK and drywall screws could scour the inside of the tank. Depsite making a custom rubber plug for the filler, I eventually ruined the paint.

So, was it worth it? Maybe. It's a nice fuel tank. But the new Emgo tanks are not real expensive. The paint job is another story. Can you keep riding the bike the way it is? I don't know. Chunks coming off aren't the same worry as having it dissolve into the gas. This can affect both carbs and valves.

Russ

Depending on how much of a "purest" you are, will affect whether you keep the original tank, or go with a replacement.

I agree with rvich, it will be a lot of work, and a ruined paint job. OTOH, a replacement tank will require a new paint job as well.

I also agree with rvich that the presence of a sealer is not proof the tank ever leaked.

If it were my tank, I would be apprehensive about taking a "wait and see" approach.
That is just me, and not a recommendation to strip or replace. You have to factor in your own fears and prejudices. We can only give you the pros and cons.

Good luck, however you proceed, and let us know.

Slick

It's not a pretty sight, seeing all those cracks in the sealer, but I wd submit that cracking is not evidence of dissolving.
I just botched a 2-part resin job, trying to use it at the lower edge of it's recommended temp range, and humidity above the max recommended. It jelled, skinned over, began to shrink, and stayed like that for several days, never getting hard, then overnight it cracked wildly. Although I did not try any solvents to dissolve it, I found that it had cured about half-way to hardness, to a rubbery state, and it will probably stay that way forever. I'm suggesting that something similar happened to the tank lining job.
If I were in your position, I'd certainly not dive into a dangerous and messy process which also threatens the paint job unless I was sure I had a real problem.
Here's a new tank you might think about:
https://www.ebay.com/itm/Norton-Com...K:MEBIDX:IT&_trksid=p2055119.m1438.l2649#rwid

I have a similar product in my tank. It looks like it is delaminating, but still intact. It has not given me any grief and I have done quite a few miles.
I suggest if you want to carry a band aid, then make sure you have a small plastic bag in your tool kit. If your tank filters block up [ easy to tell as it wont like full power or it will just stop], remove the tank. Put the plastic bag smoothly over the filler hole and close the cap. Turn the tank upside down and remove the taps. The rest is easy.
A friend got a leak in his 650 tank. We did the same and fixed the leak at the bottom of the tank with a tank repair kit. No petrol was lost in the process and the tank had just been filled.
Dereck

If you are doing the acetone treatment, I would suggest removing the gas cap to get it out of the way, and use one of those big test plugs they sell at the hardware store plumbing department. The kind with a wing nut on top, and a rubber seal that expands when the nut tightens. They seal tightly. After you drain the gas out, and you want to test if your plug is sealing, fill it with water, and turn it upside down, to check things out. Also, if you have some old petcocks, use those instead of the good ones, remove the filters, and in some cases, the sealer will dissolve, and let the stuff run out without plugging up the petcock. I've masked off paint jobs to prepare for the inadvertent bit of acetone that may get on your paint. If you do that, make sure it's secure, and you don't get anything under the masking. If you are going to paint it, no big deal, but I've removed several of these coatings with acetone, and have yet to ruin a paint job.