gas tank sealing

After emptying my tank i took a look inside. I am a bit confused by what i found. First off there is no rust, but there is whay may look like a silery coating (por 15??). The issue is the tank has what looks like varnish and even maybe some of the coating is coming off. So...how do i remove the varnish? THe rust doesnt seem to be the issue the varnish is. Suggestions??

First remove the old POR-15 with MEK. The MEK will remove much of the varnish also. Than use this stuff or a strong carburetor cleaner.
www.hirschauto.com/products.asp?dept=19

Muriatic acid will also remove the varnish with any rust. But first flush the tank with some rubbing alcohol to remove any left over gas.

I successfully removed Kreem with Acetone a few weeks ago, but it took a loooooooot.

Then I sent my tank to a radiator shop and they removed rust and then seald the tank for 150$.

Otakar,
in using MEK how much of the tank should i fill 1/2 whole?? Ok then what swish it around for how long? Then rinse with water and finally seal it?

Put in about a quart of MEK and swish around, allow to sit a wile and swish some more. Repeat until you can see that it is dissolving. Poor out and repeat. Poor out and repeat again until it comes out clean. Once everything is gone, repeat with Acetone. Acetone is Hygroscopic and will mix with water. Once you have done the Acetone flush than take a look to see if you have any rust. If you do than flush with water and than with Muriatic acid. This will remove any rust. Flush with distilled water, flush with Acetone, allow to dry and seal the tank.

bumping this thread it's dinner time and the yak box needs attention...need to read this tonight...i got a MKII tank with no dents media blasted and in good enough shape to run as an extra set while getting my orig set painted...trouble is i see kreem i think inside and want to maybe understand better what i may have...bump...yes honey i heard you ...blah...blah blah

One comment I'd like to make, is that my method of cleaning a tank has never necessitated a repaint.

Bill

trianglelaguna wrote:

...see kreem i think inside....

Acetone dissolves Kreem (and paint, so be careful).

Good Fortune!

Does anyone know if MEK will dissolve the KBS Gold standard coating? I had trouble with this stuff even though I followed the directions to a T. Lot of bubbling at the bottom of the tank. I started to break it up with a long screwdriver and underneath the bubbles was a sludgy mess. I will try that Bill Hirsch kit. Thanks! The color of the gold sealer that KBS sells is silver by the way. I dont think its expoxy based.

If it is a single component than it is nor epoxy. MEK should dissolve it.

This thread helped me out a lot. The Bill Hirsch kit is on its way. I didnt get the MEK only because I could not find a small bottle of it so I used Jasco paint stripper to remove the KBS coating and it worked. I figured KBS is now selling a "stripper" so I figured the stuff I had laying around would work and it did. It bubbled like paint would. I flushed it out with mineral spirits but I probably should have used something else. There is still some crud left in the tank. I might use acetone next with some type of media to swish it around to get all the little bits of sludge out. I am starting to wonder if the KBS is nothing more than a fancy paint.

All these sealers are nothing more than "some fancy paint" JUST MAKE SURE that you remove EVERYTHING IN THE TANK down to clean metal. If there is ANYTHING left in the tank besides clean metal the coating will bubble.