gas tank problems

Steve in Tampa

Senior Member
I have a 1930 stock coupe with gas tank rust flakes in the tank that clogs up the fuel line and everything in its path . yes I have an inline filter . I have flush and flushed the tank and every time I do it I get 2 tablespoons of crud.Is there any thing that I could speed up the process with by adding something to it to dissolve the rust . Then I need to seal it . I do not want to take out the tank, it is a restored car maybe 8 years base coat clear coat. HELP Please steve
 
I used Evapo rust in a Model A gas tank and it turned opaque yellow with a bright yellow precipitate. I think it reacted with the Tern coating and dissolved what Tern coating that was left. It did not work on the rust after the yellow change.
 
put in one of these for a while!
 

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no screen top or bottom . Poured gas through it 20 times.Blew with air sometimes it would stop up, and I would blow air from the bottom to the top. It seems like there is no end to the crud commin out. steve
 
Yes it does. I have a indented firewall(easier to do), and I use the dirty leg plus an inverted pea trap. I get a 1/2” build up in the dirty leg every year. Also every so many years, I re flush the tank. Works good for me.
Just to add: I can run the tank to where the float is sitting on the bottom of the tank and no longer moving.
 
What works and is simple. This is how I fixed my 30 fordor with the same problem.

First you need to flush the tank.

Take the valve off and put a ball **** valve on.

Depending on your own wishes use gas or diesel, a gallon or two, and put it in the tank.

Shake the car. Then drain into a large funnel with a filter or cheese cloth.

Repeat until you see a noticable reduction in crap.

Put a short piece of copper tubing on the end of your original gas valve. This will prevent junk from getting stuck in the valve. You will remove this at a later date.

Yes, I am aware there are filter things. They do not get rid of the problem and you will always never be able to run your tank down.

Make sure the original fire wall filter is in place. I mean it has an original Ford filter screen on it. Not a repro. The Ford screens are built different and work.

Make sure the original filter is in the carb. Again the original screens are built better then the repro.

Drive your car a lot.
I used a glass bowl at the firewall because I could. It got a lot of crap at first. Never did I get anything at the carb filter or in the carb bowl.

Eventually the amount of crap you catch drops off by quite a bit. Then it is time to take the little tube out of the valve.
 
I used Evapo rust in a Model A gas tank and it turned opaque yellow with a bright yellow precipitate. I think it reacted with the Tern coating and dissolved what Tern coating that was left. It did not work on the rust after the yellow change.

I have received numerous tanks where customers did the same thing at the recommendations of others only to have it fail. The issue is the bacterial will neutralize the rust flakes however it will not dissolve it. Then you have loose flakes that the sealer does not adhere to very well.

Therefore, the only way that you can be assured the sealer will grip to all portions of the tank is to use media to etch the metal giving the sealer a mechanical bond. Even chemical etching acids are hit or miss on creating a good mechanical bond.
 
I washed a very dirty tank out with a pressure washer and lots of detergent after removing the valve and placing a bucket in the car. Then sprayed the inside with meths to absorb the water and blew compressed air in to evaporate the meths. This was an unsealed rusty tank, full of dirt.
No further problems after that and is is 6 or 7 years since I did it.
The tank remained in the car.
SAJ in NZ
 
Hi Steve,

I have (had) a similar problem. My solution is to put some large and roughened brass nuts in the tank. They slide over the ground during the ride and scrape away dirt.

At the same time, I allways drive 60 ml MMO per tank filling. That solves old prisoners. For every 1000 mls I find half a teaspoon of rusty sand powder in the filterbowl/water separator.
 
That tank is never going to get clean while still in the car.Clean enough to use,yes.Clean enough for sealer? No way.I always found the worst of the rust is on the underside of the top.I use the finger screen in the tank,you take the gas valve out and just press it in the opening.Nothing but the screen protrudes into the tank,so you can run it until it is bone dry.That keeps the chunks and flakes out of the valve,that is what scores them.Keep the flushing up,at some point what is loose will come out and what is tight will stay and won't hurt anything.This is a very common thing with A's.Putting the cart before the horse and painting the car before the tank is properly dealt with.
 
i don't like sealers.
if the tank is not cleaned up properly the sealer will eventually de-laminate, big problem when that happens and i also think the only way to rectify the problem starts with removing the tank.

if removing the tank is an absolute out of the program,
then
keep straining out the rust through the use of a trap, an extension on the tank valve, plus the glass sediment bowl with the correct screens, the carburettor screen and maybe even an after market filter closer to the carb.
 
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