Safe Way To Drain Gas Tank

[Bingster]

I have a '47 DeSoto Custom and would like to drain and clean the gas tank before going too far with the fuel system. I assume you just take the plug off on the tank and drain the gas? Silly question, but where do I put all that gas?

[Jerry Roberts]

If the gas is still good , you could put it in another vehicle . 

[desoto1939]

Or store it and use in your lawn mower.  Just be carefule when draining the tank, the gas fumes can get to you and make you feel sick.  Keep lots of air circluating to get rid of any fumes.

 

ALso not open flames from anything near the car. The vapors is what will ignite.

 

Rich Hartung

[MarcDeSoto]

I assume the gas in your tank is over 40 or 50 years old.  Don't reuse it or you could mess up whatever you put it in.  When I drained my 48 DeSoto tank, the gas smelled rotten.  You just drain into the same sealed container you drain your oil into.  Put the cap on and take it to your local Auto Zone.  Tell them you have some old gasoline, and they will drain it into the right container.  

 

I took old gasoline to an auto store once, but that was 30 years ago.  Sniper is right that they won't take it now!  

 

Edited March 6, 2023 by MarcDeSoto

[Sniper]

Autozone might do that in California, they don't do it here. 

[Los_Control]

I assume it is not good gas, otherwise you would not drain it to clean the tank.

 

I would put it into a container to hold it. I have several gallon jugs around for things like this.

I would use it to clean parts with .... I then leave the parts tub outside and the gas evaporates.

 

I once used some to pour into a large red ants nest. This nest was huge and right at my gate to take my trash out to the alley bin.

 

I know it sounds terrible .... gasoline is refined oil that comes out of the ground.

 

What ants I did not kill, they moved to a new home and the grass that was gone because of the nest came back in weeks.

I also used some on a tree sapling growing right next to my home foundation. I cut it down & tried to kill it by removing it .... just kept coming back up.

I poured some gasoline on it and it died. Again the grass grew right back in ..... I know, I expect grief for suggesting this.

 

Modern fuels evaporate so quickly. I have a fence line that is very difficult to keep the weeds out.  Give the weeds a couple dry days, feed them some gas & they suck it up instantly & die.

But the soil is not damaged & the grass grows right back in.

 

So beat me up for pouring gas on the ground, I have done it several times & will continue to do so in the future .... on targeted areas.

[Bingster]

Is the inside of a gas tank clean? Does rust get into it? How do you know if you need a new tank or do the rocks and solution rattling around bit?

[MarcDeSoto]

take the sending unit off and look at the inside with a good flashlight.  Most tanks need to be treated for rust.  I had my radiator shop do it.  They will have to cut a 6 X 6" square off the top of that tank in order to remove the rusted all to hell oilite fuel filter that won't work now.  Then they will treat the rust and paint the inside with an ethanol resistant rust resistant red paint.  Then they will braze the metal square back on and paint the tank.  

[Bryan G]

If the gas has turned to varnish, check with your county recycling authority. Twice a year we have an event where you can drop stuff like that off. That's what I did with the stale gas out of my car. Free, no questions asked. I'm in a rural area. If they do it here, I would think they would do it many other places.

 

Be careful with that drain plug-I was afraid to put too much torque on mine as the metal seemed very thin around it. Once I dropped the tank I decided it was too far gone (when I sat it on its side it started to leak.) Rather than reseal it I just bought a new one, but depending on the model that might not be an option.

[47 dodge 1.5 ton]

As to getting rid of the old gas— I set 4 buckets outside for a few weeks and covered when calling for rain. Enough evaporated to put in (1) bucket that I kept for cleaning parts.

  Recommend if you can buy a new tank, go that route. I had poor luck with having the tank coated. Ended with red fuel and goo inside the carbs then still buy a new tank.  I’m sure some do better work than others, but not a very accessible area to ensure good quality workmanship. 

[Labrauer]

I had an old Plymouth I bought from my brother in law one time that has set up for years (about 6) to be fact. I dropped the tank and inside was a lot of gunk and crap. Took the sending unit out empty the what was left of liquid gas washed it out with a pressure washer. I put a heavy long chain in the tank with some more water then shook the heck out of it. After a few times of this the tank inside looked brand new worked fine for years. I've done lawn mower tanks and other gas tanks the same way. I have also taken one to a radiator shop and they boiled it out with the same stuff they do the radiators with. Now days we haven't anyone around here that is into the radiator fixing anymore it seems it is cheaper to just buy a new radiator than to have one fixed I guess. The last radiator shop around this part of the country wouldn't work on the old honey cone radiators in these old cars he said no can do.

As for getting rid of the old gas what ever you do don't let the EPA catch you dumping it into the ground oh boy what a huge fine you'll pay.

Edited March 7, 2023 by Labrauer
adding to response

[Semmerling]

 

Here is what we know thus far...

"I have a '47 DeSoto Custom and would like to drain and clean the gas tank before going too far with the fuel system.
- Good idea. If the fuel is bad it will ruin any work you do on the fuel system.

 

Here are the questions you asked 

 

"I assume you just take the plug off on the tank and drain the gas? "
- If you take the plug out liquids will come out quickly until it empties or is replugged
- If the fuel is still able to go out through the fuel lines, you could do that too.

- As mentioned, one can go in through the top in a number of way

- You could safely crimp the fuel line, properly deal with the gauge top end and anything else.....and remove the tank filled. Then you would not need to deal with the fuel....or the old tank.....and you could find a proper place to deal with both. z
 

"Silly question, but where do I put all that gas?"  
-In a fuel safe container sized for the amount you might/do have. Or you leave it right there....read above. 
 

"Is the inside of a gas tank clean?"
-It can be clean or it can be in a complete state of ruin
- Does your car have a fuel filter. If it does, did you look at it? 

"Does rust get into it?"
- Yes it can and does especially when the tank is old, not sealed and not full of fuel. 

- Does your car have a fuel filter? If it does, did you look at it?

"How do you know if you need a new tank or do the rocks and solution rattling around bit?""
How do you know if I need a new tank or I should try some of the offered cleaning tips?
- Regardless of keeping the OLD TANK or getting a NEW TANK the old tank's fuel and tank are still going to have to come out.

- Remember if you GET all the fuel out and then CLEAN the tank you will need to deal with all the CLEANING SOLUTIONS/DREGS as well.
 

But forget all that, you need to find somebody that can safely work with fuels and is capable of knowing what to do when see what your situation actually is. 

 

Better that than having 
Where he Blue of the Night meets the Red Flames and Black Smoke of the Day

 

 

 

 

Edited March 7, 2023 by Semmerling

[Sam Buchanan]

If you live in an area of low humidity best practice is use a grounding strap connecting the tank to the drain container. This can prevent a catastrophic static charge boom boom..... 

[Adam H P15 D30]

I use old gas to light my burn pile in the spring time.

[Bingster]

Thanks for all the input.

[allbizz49]

Light it up or throw it on your weeds  

[52ismine]

Had a very slight drip from the tank plug on my ‘52 Plymouth. Kept tightening it but still leaked. Ran the tank low enough to make sure it would fit into the 2 clean 5 gallon pails I had. That plug gasket was the 1 rubber fuel related item I never replaced, the ethanol blend fuels finally ate it away. No big deal removing the plug unless like mentioned earlier that the metal might be “soft”. 
 

As far as getting rid of the old/bad gas, get some containers and write “GAS” on them, fill them up, put them in the back of your pickup and drive to Walmart. Park your pickup with the tailgate down, go shopping for an hour or so and when you come back the containers will be gone and the bad gas is no longer your problem.

Edited March 14, 2023 by 52ismine