Cleaning Gas Tank 'in place'

[pbishop]

Did a complete body-off restoration of Model A 25 years ago. Cleaned gas tank at that time, but did not use sealer. Last summer went to a Weber carb set-up (very happy).

Problem is I have had to change fuel filter several time since then (rust crap build-up). Before I installed Weber I cleaned the tank with detergent and water, then flushed twice with acetone (lots of crap came out). Used hair dryer and then vacuumed out as best I could. Let sit for a few days to fully dry. Yes, the acetone destroyed the ‘float’.

Months on I have had to change the fuel filter several times as rust trash builds up. I went back to using the glass bowl before the fuel filter, but without a gas pump it slows the fuel flow down to slow.

Here is the question: I want to clean the tank again, but I do not want to take the gas tank out of the car.

I have seen several videos on YouTube concerning what to use:

Metal Rescue, Muriatic acid, vinegar, Oxy Clean, and ‘The Works Basic’ (a toilet bowl cleaner). From the videos The Works Basic seems to do the best job.

ANY suggestions/ opinions from experience?

[Synchro909]

There are several sealing solutions on the market here and I'm sure there will be even more over there. The best ones as far as I'm concerned are a 3 step process. First, a caustic wash to remove any oiliness so the second stage can get at the metal. Second, an acid etch. Some recommend phosphoric acid but if the rust is bad, I prefer to speed things up and use Hydrochloric acid (HCl) in a fairly strong solution, swirling and turning frequently. Once the rust is gone, then I use a Phosphoric acid solution for the white residue it leaves and the surface doesn't start to rust again immediately. After a thorough drying, use the sealer of your choice. As with most things, the secret to success is in the preparation.
This requires the tank out of the car and I've done that on my '29 Phaeton and '30 CCPU - both times without damaging the paint. Neither car has been a problem since. I don't think you can do it properly with the tank in the car.
I'll follow this one!

[BRENT in 10-uh-C]

The 2 biggest issue that we have personally experienced is that the Hydrochloric acid tends to be tough to neutralize unless it can be pressure washed and/or scrubbed away. That is tough in a tank where you cannot access the inside. I cannot even begin to tell you how many Model-A tanks I have received where the owner admitted they tried Hydrochloric acid first. Then after awhile, the sealer starts to dislodge from the tank due to rust below it and it gets sent to us. Then when we open the tank, the metal is usually eaten away by the lingering acid rendering the tank useless and too far gone to repair.


The second thing we have found is tanks that are partially coated with sealer are just the same as not coating one because the fuel sloshing tends to erode the edges of the sealer, AND it allows air to enter causing rust. Therefore, for a tank with baffles and one that is still mounted inside the body, it is going to tank 10-11 gallons of sealer to totally fill the tank to ensure it is completely coated. With sealer running around $100 a gallon, spending $1,000.00-$1,100.00 on product seems like an expensive way to shortcut properly restoring one. Then ....and you are hoping after spending that kind of money that all of the rust has truly been eliminated and it doesn't come back! If so, that is a lot of time & money wasted!!


/

[WHN]

28 and 29 tanks come out fairly easily. 30 and 31 much bigger job.

Tank must be removed to do job right. Anything else will just be a pain in the ###.

Our keeper 29 was done over 30 years ago. No problems since. If it’s worth doing, it’s worth doing right. Enjoy.

[BillCNC]

My tank has some rust particles also and I have a question about the process.

It seems to me that the chemicals used to clean out the tank would be extremely destructive to the paint if it was to get on there by accident. I'm not at all confident the cap would give me a 100% seal.

How do you prevent that?

Regards
Bill

[WHN]

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With tank out of car. We removed gas gauge, lines, cap. Than very carefully taped closed each opening. Did not rush job. Our 29 tank came out great. Put sealer on three times. Let it sit over place where steering column is mounted.

Follow instruction completely, and take your time. Worst case, you will have to touch up or repaint gas tank. Hopefully not. Enjoy.

[BillCNC]

My car was painted 10 years ago, so matching that paint to the hood and body will be a real doozy to say the least.

I do some prototype Vacuum Bagging at home and use a brush-able silicone on some of my molds. I am tempted to try it on a the paint in a place that cannot be seen to see if it is compatible or not. Seems like it might help around the openings.

https://www.smooth-on.com/product-line/ez-brush/

I think I'll mix up a small batch and test it against a few different chemicals I have laying around here.

Regards
Bill

[1931 flamingo]

Put some large magnets on the bottom of the tank and install the "pencil" filter. FWIW
Paul in CT

[ronn]

I agree with Paul- can run for years.................!

[JOHN CT]

Originally Posted by 1931 flamingo

Put some large magnets on the bottom of the tank and install the "pencil" filter. FWIW
Paul in CT

Okay
What size magnet would you use? And where’s the best place to put it?

[vstol]

Get the concentrate from R 911 out of Hickory NC it will do 16 gallons when diluted about 50 dollars. Leave it in the tank for a couple of days rocking the car occasionally drain should be clean. It is non-toxic biodegradable, my sedament bowl is clean. My tank had been empty for over 50 years, couldn't be happier.

[johnbuckley]

Originally Posted by JOHN CT

Okay
What size magnet would you use? And where’s the best place to put it?

size doesn't really matter so long as it stays to the tank. I'd put it d as centrally as you can so that you'll see the rust as it builds up into a pile and later remove the particles with a pick- up magnet.

[ccb360]

Magnets recovered from a discarded computer hard drive are very strong and work great. Just don't get your fingers pinched when placing the magnet.

Locate the magnet near the fuel shut off valve where collected debris may be seen and recovered from gas cap filler neck.

[cpf240]

Originally Posted by vstol

Get the concentrate from R 911 out of Hickory NC it will do 16 gallons when diluted about 50 dollars. Leave it in the tank for a couple of days rocking the car occasionally drain should be clean. It is non-toxic biodegradable, my sedament bowl is clean. My tank had been empty for over 50 years, couldn't be happier.

Will this damage the fuel gauge float or gaskets?

[Clem Clement]

When we tried and failed to clean a tank last fall, We used two rounds of Evaporust in the 28 tank. after rinsing we still had nonmetallic scum/particles that floated. They would move over the exit pipe and plug it. We gave up and told the owner to have someone do the job correctly

[steve s]

Can you say, "trail of tears"?

Pull the tank and do it right the first time; it's a lot easier than coping with a failed first try in order to do it right the second time. I had mine done by the Renu franchise 20 years ago and have had no problems.

[cpf240]

Originally Posted by steve s

Can you say, "trail of tears"?

Pull the tank and do it right the first time; it's a lot easier than coping with a failed first try in order to do it right the second time. ...

I agree with you, to a point.

My A had its "restoration" started over 30 years ago, and I hope to finally complete it and actually be able to drive it. The paint has already been done, though it has suffered in storage all these years, and isn't really 'correct' for the year.

My father started this project way back when, and he has never seen it on the road, and only puttered around a parking lot with it. My goal is for him, and myself, to have a chance to drive it before too much time passes.

Sometime later I do intend to repaint it, and that is when I'll pull the tank and send it to Brent. I just hope he is still doing such jobs then! :-)

So, if something like this R 911 stuff can clean up the tank enough for that purpose, I think it might be worth doing for the short term.

[Kurt in NJ]

I used to have a "standpipe" to keep the debris from the filter, but stirred up debris still got on the standpipe, so I took out the valve,rremoved it, filled, sloshed, used magnet and got out all I could, then I went on a drive to a show, after 4 days of driving and cleaning at night no more debris in filter, after that 3000 mile drive the filter stayed clean enough that it didn't clean it for 10 years I don't have the standpipe anymore, I would rather clean the filter every couple of years

[kenparker]

I bought a basket case couple months ago. Just, this week got the chassi back in running condition. Looked in the gas tank, which is not in the body, and discovered peeling sealer - big time -flakes as big as my hand. Now i have ot decide how to handle the flakey problem.

Partially done restoration was done 30 years ago and put in storage.

[steve s]

Originally Posted by kenparker

... discovered peeling sealer - big time -flakes as big as my hand. Now i have ot decide how to handle the flakey problem ...

That would be one of the Trails-of-Tears.