Varnish buildup in gas tank

[alexgt350h]

Have a gas tank out of a 69 that has been sitting for 10 years or so and has varnish buildup, even though tank was drained before storage. Getting lots of crap plugging up fuel filter. (yes , all lines were blown out)
Any ideas on how to clean this mess out of tank? Tank otherwise is in excellent shape, it was replaced in the early 90's.

Brent

[rhjanes]

B12 Chemtool. Put it in.  Slosh.  Let sit.  Slosh.  Etc.  Eventually dump it out and repeat as needed.  Sea-Foam should also work. 

[67 GT350]

I had a "garage find" to which the car sat from 1975 until 2012. I went through trying to save all of it from the tank to the hose that connects to the fuel pump, it was all rot free, California car to boot! I soon got tired of it and replace everything from the fuel tank to the intake! Yes, gas cap, inlet to tank, fuel sender, tank, lines to the fuel pump, fuel pump, line to the carburetor, the carburetor. Everything! Done. Then, rebuilt the engine, transmission, u-joints, rearend....Catch my drift, had to do everything.
That was in addition to brakes, etc, etc, etc. BARN FIND! HA!

[Bob Gaines]

A different story in years past and for obscure applications but what with the economical price of quality reproduction Mustang gas tanks it makes sense for many to simply exchange the gas tank. Of course you have to consider what your time is worth , cleaning materials expense and piece of mind that you got all the foreign material out given you can't see inside the tank before you decide if it makes sense for you to exchange. FYI the same steps to clean the tank are used to replace the tank so only difference is cost of tank typically.

[alexgt350h]

I figured that I would have to change out tank, but was hoping for a fix.
Who has good deals on 69 tanks?

Hopefully see you all in Indiana soon!

Brent

[The Going Thing]

Radiator shops can usually get them cleaned out.  Did you consider that option?

[98SVT - was 06GT]

Radiator shops can usually get them cleaned out.  Did you consider that option?

Old radiator shops that had big dip tank. Today all they do is replace Chinese aluminum radiators.

[The Going Thing]

Not here in the DFW area. There are still real radiator shops.