Tank liner removal

[shovelheadstan]

Anyone out there have any suggestions on how to remove caswell tank liner other than using muratic acid

[pan620]

I have used MEK

[PaulCDF]

The only suggestion I can think of is maybe contact Caswell for advice on removing their liner?

[T. Cotten]

I know better than to ask this, ShovelheadStan,...

But why must you remove it?

....Cotten
PS: Your instincts are good to avoid the acid!

[shovelheadstan]

Recently on a trip I noticed that the liner was hanging down in the tank. Must not have got it clean enough before I applied the liner.

[T. Cotten]

Please don't blame yourself, Stan!

Many decent sealers have failed in the constantly-changing fuels; Two kinds of Caswell's failed my immersion tests (but at least they lasted months longer than POR-15). 'Red-Cote' was the most resistant, but since I ceased testing years ago, it doesn't mean there isn't a fuel out there that will eat it too.

Combinations of summer blends from different regions become more digestive than any one brand alone.

Pan620's suggestion of MEK is as good as any, but please be careful with it. Unless you have soldered-construction tanks, I wouldn't consider replacing the sealer, just removing loose lining.

....Cotten

[chuckthebeatertruck]

So, here's the skinny; there are four different chemical compositions for common tank liners.

Two of those are softenable with a hot methyl base -- whether mek or acetone. These include RedKote, Kreeme, etc. What's weird is how nothing really touches RedKote, except immerision for long periods of time in MEK.

Por-15, Rust Bullet and the like are isocycanate polymers. They harden in the presence of moisture. They are softened by Methyl Chloride (the real stuff that is no longer on DIY market)

Caswell and most commerical liners are phenol epoxies. They can survive most anything but Methyl Chloride

When MTBE was more prevelant in fuel -- pretty much only RedKote and some epoxy liners survived more than a few years of constant immersion.

Cotton's advice is valid -- unless you need the liner, see if you can survive without it.

Muriatic only works well on stuff that is softenable in MEK. It cannot dissolve iso polymers or phenol epoxy as it's pretty easily defeated by polymers. It will, however, eat the nuggets out of your tank if it gets stuck behind the liner.

So, here's how I attack these things these days cause I can't get Methyl Chloride anymore:

1) Fill with a gallon of MEK or Acetone
2) Cap and wait 3-7 days, rotating regularly
3) Pour out the mess
4) Use a bent and flattened piece of 3/8 round bar to scrape as much liner off as possible
5) Fill tank with pyramidal tumbling media, or fresh drywall screws. A solid pound or so.
6) Stick in the dryer surrounded by blankets for several hours or even overnight if you can rig it up
7) Use muriatic to loosen any remaining bits
8) Flush, inspect and repeate 5-7 until nothing but clean metal.


It takes a while sometimes. When I did a tank for Mrs Chuck this spring -- I had to remove one Kreeme like liner applied over an old epoxy liner! It was a royal pita and took many hours of tumbling and messing about with it.

But, a lot of patience later and it was done. It then held liquid just fine after all the repairs - but I redkoted anyways because I didn't fully trust it would remain leak free for years to come.

I have yet to have a failure from RedKote or Caswells -- but I have had a few Kreeme failures and will never, ever go near that mess again.

[craig (DE)]

I need to remove some kind of liner in the oil tank side of my 1942 WLA. When the oil gets warm, this stuff breaks off and clogs my oil pump. Not good!
I do have a bottle of methylene chloride left over from my early career as a chemist.

[PaulCDF]

Craig;
May want to start a new post.
I am not familiar with the 1942 WLA oil tank set up. On my 46 Indian the oil tank is on the right side with the gas tank separated by a tin wall. I got repo tanks from Iron Horse when they were still making them. NO liner either gas or oil tank. I red coted the gas tanks but left the oil tank raw rational oil will keep oxidation down. Just what I did.