How To Remove Varnish From Gas Tank?

chodie

Seaman
Joined
Jan 1, 2008
Messages
52
I have a metal gas tank for a 1954 johnson 10 hp. It is in good shape except the gas has evaporated and left varnish in the bottom. Is their any way to clean the tank?
 

rolmops

Vice Admiral
Joined
Feb 24, 2002
Messages
5,299
Re: How To Remove Varnish From Gas Tank?

Yes there is.
You can either put half a gallon of paint thinner or straight gas in the tank with a bunch of roofing nails.let it sit for a day and then pick it up and shake the tank real hard. The roofing nails will scrape the by now soft varnish off the steel bottom.Repeat the process a few times and you should be in business.
 

rndn

Commander
Joined
May 20, 2007
Messages
2,323
Re: How To Remove Varnish From Gas Tank?

I've also heard of using a bunch of BB's instead of the roofing nails.
 

rjezuit

Chief Petty Officer
Joined
Sep 24, 2007
Messages
418
Re: How To Remove Varnish From Gas Tank?

Clean gravel/small stones works well also with the solvent. Rick
 

F_R

Supreme Mariner
Joined
Jul 7, 2006
Messages
28,195
Re: How To Remove Varnish From Gas Tank?

Use a bottle of good old rubbing alcohol from the supermarket instead of the gasoline. It works better and doesn't blow up from sparks from those roofing nails.
 

tmcalavy

Rear Admiral
Joined
Aug 29, 2001
Messages
4,005
Re: How To Remove Varnish From Gas Tank?

Good advice so far. The trick is agitation...the endless shake, shake, shake. Takes patience but it works. After you get it clean, take it to the car wash or use a pressure washer to clean/rinse it out. Rinse with clean water several times, let it almost air dry completely then pour a bottle of 93% octane rubbing alcohol in there to evaporate out the remaining moisture. Now you're all set to re-use it. There are gas tank sealers/liners out there that will put a new skin on the inside of the tank if you think rust may be a problem. Google them up, I like the ones rated for aircraft use...they are resistant to alcohol-added fuels, like the ethanol blended gas we get nowadays.
 

wavrider

Chief Petty Officer
Joined
Nov 26, 2007
Messages
543
Re: How To Remove Varnish From Gas Tank?

Acetone works wonders with varnish as does carb parts cleaner, expensive though.

there are severla tank liners on the market, I have teried all of them on olf ford tractor tanks, they will seal the tank, but if any residue or heavy spots where the liner accumulates more than a 32nd of an inch it does not cure and have had problems with the stringy residue clogging filters and getting itno carb.

I finally threw the old tank away that i tried to seal with the liners and put a new one in.

You may have good luck with a smaller type tank if you use the liner
 

Lone Duck

Master Chief Petty Officer
Joined
Oct 17, 2007
Messages
868
Re: How To Remove Varnish From Gas Tank?

metholhydrate works too. Also good for getting it out of carbs. but it is hard on some gaslines and diaphams.
 

rjezuit

Chief Petty Officer
Joined
Sep 24, 2007
Messages
418
Re: How To Remove Varnish From Gas Tank?

Gumout or some product like that comes to mind also. Rick
 
Top