Gas tank varnish
 

Has anyone had good luck cleaning old gas varnish from a model A tank. I have a 29 gas tank to clean that sat 30 tears with about 5 gallons of skanky gas in it. The bottom and sides are covered with a dark sticky varnish that keeps stopping the gas flow. I would like to clean it once and remove all traces of this old gas.

Re: Gas tank varnish
 

acetone will - one of the main ingredients in carb cleaner/seafoam/injector cleaners that removes it instantly. Be careful as its highly flamable and the fumes can get to you so do it outside. I bet seafoam in a heavy concentrate would remove it as well (2 cans per 10 gallons) mixed with E10 fuel will remove it. Ethanol makes a great cleaner as you have seen regular gas leaves a varnish behind.

Would be best out of the car so you can tumble it around and not worry about the varnish gunk clogging up the carb.

Re: Gas tank varnish
 

After trying PB Blaster, Acetone, Lacquer Thinner, Paint Thinner, gasoline, kerosene, WD 40, Kroil, Liquid Wrench, etc., etc., to clean old gasoline varnish ....... I found that hot tap water mixed with POR 15 Marine Clean, (4 parts water to one part MC) will clean more thoroughly and quicker than all of the above.

Used MC in my Model A gas tank which sat in car collectors storage for 30 years.

One gallon costs about $25.00, mixed with 4 parts hot water = 5 gallons; for $25.00 it is "clean" ........... but wait ....... drain MC from gas tank, strain it through a cotton T-Shirt, and MC can be used again and again to quickly and thoroughly clean petroleum based products from any and all Model A parts ...... even make the interior coils of an old radiator shine once again.

Possible Forum Member Rejections for Trying POR Products:

Cost too much ..... most here appear to be searching desperately and waiting to read an article on how to entirely, mechanically rebuild a Model A engine, transmission, and differential by adding a $1.50 box Oatmeal in the radiator ...... Why wait?

Re: Gas tank varnish
 

I used and liked the marine clean gas tanks and old oily radiators.

Re: Gas tank varnish
 

This varnish does more than stop the gas flow! If you try to run the engine without getting rid if this gunk, it will dissolve in the new gas and leave a sticky residue on the exhaust valve stems. This is often why an engine that sat for many years runs great right after being resurrected, but gradually gets worse. So clean the fuel tank first (and not with H.L.'s $1.50 box of oatmeal)!

Re: Gas tank varnish
 

Hi 40,

As far as I know, (and I could be wrong) ....... but, exactly how to specifically use the long anticipated $1.50 box of "Oatmeal-Total-Model A-Drivetrain-Overhaul-Kit" ..... I don' think this has been formally introduced ......... "yet".

So in the meantime .... we all will just have to wait for someone to tell us about it with a few details like ..... does it have to be "Organic Oatmeal" ..... or just ordinary "Quaker Oats" oatmeal ..... plus any other ancillary ingredients that may be required.

Re: Gas tank varnish
 

Order Sodium Hydroxide (Caustic) from a vendor such as Soapgoods and mix it up with water. This is what the radiator shops used some two decades ago and before to dissolve organic matter inside of radiators & tanks. Hot (--or warm) Caustic makes a great product for removing grease on Model-A parts.

Re: Gas tank varnish
 

I used E85 to take care of gas that had been in the tank sense 1965 worked good
Good luck
Tinkirk/Terry


Sent from my iPhone using Tapatalk

Re: Gas tank varnish
 

As parochial as this may appear, extreme caution is suggested:

1. Some cleansing materials suggested above, and many other cleansing materials suggested on any and all vehicle Forums may possibly totally dissolve any type of vintage Model A paint, or new paint, all the way down to bare metal.

2. If your gas tank is left in your vehicle, or is removed from your vehicle , employ every means possible to try to avoid spills on any finished exposed surfaces .... funnels, drop cloths, etc., etc.

Re: Gas tank varnish
 

Yep, I used E-85 to remove the old tank liner someone put in my Studebaker gas tank 23 years ago. It worked great.

Re: Gas tank varnish
 

Thanks H.L. This is good information that the world needs to hear! Not to poison the environment with toxic solvents. And to reuse on other projects!

Re: Gas tank varnish
 

Thanks everyone. I plan to take the tank out. Sodium Hydroxide is Lye and I think I can still buy it locally. If not Drano is just sodium hydroxide and aluminum chips...which I can easily pick out. I have Marine Clean and I will try that also. If that fails, I will try E-85 0r Acetone. I will post my results as I get this done. I have a good inch of crap in the bottom of the tank.

Re: Gas tank varnish
 

Just sincerely hope you do not have what I had in my Model A gas tank 10 years ago.

Someone read the old MAFCA 1970's Restorer article on mixing and providing a "Permatex/Alcohol" homemade, Model A tank Sealer, and tried it in my Model A gas tank years ago.

This car stayed in the previous owners' storage for 30 years and had about 200 miles of use while using the former non-ethanol gas.

After I acquired it and after filling the tank with 10% ethanol gas, the black tank sealant dissolved, mixed with the ethanol gas, and after the very first 15 miles of driving, (after a total mechanical drive-train re-build), the insides of the carburetor and the intake manifold looked like it was painted with a thin layer of tar.

This black sealant in the tank, carburetor, and intake manifold just laughed at my trying PB Blaster, Acetone, Lacquer Thinner, Paint Thinner, gasoline, kerosene, WD 40, Kroil, Liquid Wrench, etc., etc. ........... but with trying just one application of POR 15 Marine Clean mixed with hot water ..... the laughing stopped abruptly ....... the rest of this experience is lessons learned and Model A history.

Just hope this one (1) experience can help anybody ... some other future day.

Re: Gas tank varnish
 

So what I am hearing is that if you have old gas from over (1) winter storage, it is best to just fill up with E85 gas to clean out any residual varnish?

Re: Gas tank varnish
 

If the tank is off the car, just use 1 gallon, roll it around and let it work for a day or two, then roll it some more, and dump it. Repeat a second time and see how it looks inside.

I haven't tried Marine Clean, but have heard good results about it.

Be sure to install the small pencil filter in the tank valve.

Re: Gas tank varnish
 

FWIW, if anyone ever tries POR MC:

If the Model A tank is out of car, add only 1 cup of POR Marine Clean and 4 cups hot tap water = 40 ounces of liquid; enough to slush around in any Model A tank.

Strain liquid through a clean cotton T-Shirt when emptying the tank the first time; and keep using this "same" MC mixture until no more deleterious material is found on a "clean" part of a T-Shirt.

This will not take long ..... MC immediately softens, emulsifies, and attacks "all" petroleum products similar to that of strong paint remover attacking hard paint.

For worse of the worse, MC mixture can be reheated to a simmer on your stove to brutally attack what no other witches brew will soften inside Model A gas tanks.

Much smaller MC concentrations, (like 10 parts water to 1 MC), can attack old ancient 86 year old grease in Model A radiators where the MC mixture is continuously rapidly circulated by the water pump, and the MC mixture is continuously heated by the engine.

Re: Gas tank varnish
 

i would say No but, just fill it with what ever gas you normally run!
E85 is for cleaning the tar like substance that forms from really old gas

Tinkirk/Terry

Re: Gas tank varnish
 

The e85 took all the paint off my gas gauge. ate the cork gasket out of the fuel gauge also.

Re: Gas tank varnish
 

If you use caustic be carefull it eats aluminum.

Re: Gas tank varnish
 

Since your taking it out of the car strap it to the front opening of a cement mixer and let it tumble the liquid for you.