I bought an old bike with aluminium tank that had sat for a long time.  It had some liquid stinky gas in it and was oozing molasses looking stuff by the petcock and a couple of pin holes.  I soaked in fresh gas for a couple of weeks and then soaked with simple green water for a short time (also shaking with screws & bolts inside).  The inside still does not look that clean.  See pictures.  Further back is what looks like a thin layer of the molasses looking varnish.  Will the standard KBS tank sealer kit be adequate for cleaning and sealing a tank like this?  If not, what other steps should I take?  I'm not planning on repainting the tank so any cleaning solvents that eat paint are not desirable.         

Yes, KBS Klean (which is included on our Tank Sealer Kits) along with a chain or nuts and bolts will remove the old fuel residue/varnish. It might take a bit of work, but it will remove that.

 

Please let us know if that helps and if you have any additional questions.

Thanks for the response.  Should it look clean before sealing or will the sealer simply seal in some of this?  Is the "stuff" in the filler neck residue or corrosion or both?   

Take a wire coat hanger and unfold it and then poke the areas. Once you do that, you will be able to tell if it is corrosion or gummy varnish type material.

 

You want to remove any loose flaky rust and the gummy varnish before doing the RustBlast and Tank Sealer steps.

 

Please let us know if you have any additional questions.

The kit is ordered but I went ahead with some agitation with nuts and bolts.  The tank was already cleaned with simple green so fumes were little to none.  I wrapped the tank in towels, put it in the dryer and packed it tight with pillows.  I then ran it with air only (no heat) for 15 minutes with the tank placed in each direction.  It may have been over kill but it looks like most of the varnish transferred to the nuts and bolts.  I read about this method and it actually works.