How do I dry out a gas tank?

[blubuckaroo]

I was getting fuel odor and some seepage from the aux tank. It was coming from the top of the tank, so it had to come out for a leak check.
I capped everything off, added compressed air and dunked it into a kids wading pool to look for bubbles.
While doing this, the rubber ball I was using to plug the filler neck blew out. The tank filled with water and sank in the wading pool.
Now, how do I dry the tank out?
I dumped out what would come put, then put a space heater on it. I'm sure there's still water in there.
What now?

 

[andyp]

Open everything up. Use that compressed air to blow out the tank as much as possible. Let it dry out for a few days. Maybe add a little gas and slosh it around. Dump it out into a bucket and see if there is still water in the fuel. These are just guesses as to what I would try.

 

[Rightpace]

Shop vac attached to inlet with tape.
Let it draw air through from vent hose.
Do not put anything flammable in tank while vacuuming, it will combust inside vacuum. Electric leaf blower works also.

 

[Rumcustom]

Shop vac attached to inlet with tape.
Let it draw air through from vent hose.
Do not put anything flammable in tank while vacuuming, it will combust inside vacuum. Electric leaf blower works also.

If using a shop vac, I would suggest connecting the vac hose to the exhaust side of the shop vac so that you are forcing air INTO the tank rather than sucking air out and into the shop vac. Even though a shop vac is sealed within the airflow, static electricity could build up and cause an explosion if the fumes are strong enough. That's just me being a little more cautious.

 

[rydog1130]

acetone will work too, its what we used in organic chem labs to clean out the glass ware...

 

[SP73]

acetone will work too, its what we used in organic chem labs to clean out the glass ware...

This is my suggestion also. I used it in my aux tank after cleaning out nasty old varnished gasoline.

 

[Steve83]

Acetone is just a volatile petrochemical - it doesn't mix with water. And as it evaporates, it will make the surface cold, which will cause condensation (water) to adhere.

Lots of warm air is the best way to get rid of water. A shop vac blowing into the tank is best, with every opening letting the damp air out - nothing taped or blocked. Keeping the tank warm (as with an electric blanket) will speed it up slightly, but it's not necessary. For this tank, I just left it in the sun for a few days.

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But water gets into all gas tanks - it's not a catastrophe. This truck drove 300 miles immediately after these pics without any problems.

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This is how it looked when it came back a couple weeks ago, still running fine:

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[Broncobowsher]

I've done it in the summer. Zip tie a shop vac hose to the condenser on the outside A/C. Other end goes into the filler neck. Remove the sending unit. After about 6 hours (hope you need a lot of A/C) the tank is all dry. No fuel smell either.

 

[Kevinehill]

In tank pumps

Just a note. In tank pumps are designed to be cooled by the fuel in the tank. If you run the tank empty or nearly empty they can overheat and wear out the pump. Years ago I was driving in a Sable with the in tank pump going bad and it would quit after 1 - 3 miles. I would let it coast to a stop and restart and go another mile or so. Late afternoon I stopped and when I went again (cool of the evening) it continue to run so I drove on. On my return trip I drove at night and had no problems but I replaced the pump shortly after that.

 

[SP73]

Acetone is just a volatile petrochemical - it doesn't mix with water. And as it evaporates, it will make the surface cold, which will cause condensation (water) to adhere

Acetone IS miscible with water. It will completely dry that tank out quickly.

 

[rydog1130]

Acetone IS miscible with water. It will completely dry that tank out quickly.

Yup, #1 rule of organic chem is "like dissolves like" acetone has intermediate properties where it will pick up oil and water

 

[chuckyb]

Agree with Steve on using some heat. It will help to evaporate the moisture out. I have restored a couple of tractor fuel tanks. Rinsed, shook out the water and pointed a space heater at the tank, a couple of feet away, and with the filler opening pointing upwards to let the moisture out.

 

[Rustytruck]

I would wash out the tank with detergent and rinse to get gas and fumes out and then use a hair dryer. you could use a smaller tube to blow in and force the air into the back and allow the warm air out the front. You cant force air into a dead headed tank.

 

[blubuckaroo]

I think I've got it dry.
I put it on saw horses, discharged a shop vac into the filler with the vents and fuel outlet open. Then I heated the bottom of the tank with a heat gun. I got it pretty hot.
I've reinstalled it and plan to put in a bottle of gas tank drier.

 

[broncobilly72]

a little water in the gas is not necessarily a bad thing. Years ago i had a steam/water injection on my bronco. After putting 204,000 miles on the engine ,it was time for a rebuild. when I pulled off the heads, I was surprised to see no carbon build up in the heads. apparently the water vapor dissolved the the carbon. there is an old trick to break down carbon build up on the valves by pouring water in the carb while keeping the engine running at a high rpm.

 

[Bronco4x4]

The biker trick is to run exhaust from a car/truck into the tank with a hose.

 

[73azbronco]

whichever way you chose pout a camera on it because if you use some of the suggestions here it could be exciting.

 

[blubuckaroo]

When I was leak testing the tank, I had it sitting in a kids wading pool. I had the filler plugged with a rubber ball. The first time the ball popped out it was pretty exciting. after that it was quite entertaining.
https://photos.google.com/photo/AF1QipOJk0JqhrcXQfCuoVn-TH4-t37TsUodF5t8GcCo

 

[Steve83]

Acetone IS miscible with water.

You're right - I forgot that it's a ketone. But it's still too volatile, and will cause a LOT of condensation. For a truly-dry surface, warm air is still cheaper & more-effective.

apparently the water vapor dissolved the the carbon.

It doesn't dissolve it - the water is driven into the Carbon during compression. During combustion, it effectively explodes into steam, blasting the ash off the metal.

...run exhaust from a car/truck into the tank with a hose.

Burning any hydrocarbon in Oxygen produces a LOT of water, which will then condense on the cooler tank walls. And all the other chemicals in exhaust aren't good for the tank, either.

 

[66CTBronco]

We used clean some of our turbine engines like that too... 22,300 rpm and a hose...

it’s tricky to balance the water in the carb and keeping the engines from stalling but it does do wonders on the intake manifolds. Just don’t stall... hard to start when it’s flooded with water lol
C