cleaning a plastic tank out?

[fe66comet]

Normally I would take it to a radiator shop if it were steel. But plastic fantastic, not so sure. A replacement is $900 bucks so I really do not want to go that route. It just has dirt and crud from sitting so I want to get the varnish out and flush it out. Thanks....... Jon

[drdano]

If the tank is the correct type of plastic you should be able to use acid to eat the junk out of there.  You'd want to remove everything off the the tank you don't want eaten though, rubber parts, etc. 

[fe66comet]

It is a factory plastic tank, just varnished up nasty. Have the sender and pump out already, that is 600 bucks. Ridiculous expensive Delphi stuff.

[drdano]

I would do a small spot test with some muratic acid and see if it reacts with the plastic.  If not, you're good to go just have a plan to neutralize the acid when you pour it out of the tank. Mask, gloves, open ventilated area, etc.

[fe66comet]

I have used acid to clean rust from steel tanks but used paint stripper on the varnish. That combo would not be very plastic friendly, maybe I could try diesel 911 to break up the scuz? It is pretty thick or scrap it and go to a Jaz cell better yet.