Welding a used gas tank

[rjardy]

Hey guys, I am looking to upgrade my fuel system and considering an in-tank pump. My tank is all but new but has had gas in it. Id like to weld the fuel return and the sump into this tank but have reservations about welding to a tank that has had fuel in it. Any recommendations on how to purge this and weld it safely?


Regards,

Rob

[raustinss]

It's like trying to take a s**t with your pants on. Can be done might be messy.cleaning it out and letting it air dry for a week obviously remove any and all parts that you can. Then be brave lol... Honestly take it to a shop and let them do it..if they will

[rjardy]

Originally Posted by raustinss

It's like trying to take a s**t with your pants on. Can be done might be messy.cleaning it out and letting it air dry for a week obviously remove any and all parts that you can. Then be brave lol... Honestly take it to a shop and let them do it..if they will

Sounds like I may be better off just buying a new tank. I like your analogy though!

[Vince@Meanstreets]

yep, they are so cheap now. Welding galv steel sucks.

[Build-It-Break-it]

Most radiator shops will clean them out and sometimes weld in what ever you desire. It's been done and isn't a big deal. Call a few and ask if they'll do it and pricing.

Galvanized is toxic when welded so just take proper precautions. Proper respirator etc.

[bigkarz]

fill the 1\5 way with water and dawn dish soap blow air in tank to mix repeat if still smells like gas poor it out and cut and weld
i did my tank and worked great

[GregWeld]

Originally Posted by rjardy

Hey guys, I am looking to upgrade my fuel system and considering an in-tank pump. My tank is all but new but has had gas in it. Id like to weld the fuel return and the sump into this tank but have reservations about welding to a tank that has had fuel in it. Any recommendations on how to purge this and weld it safely?


Regards,

Rob

Rob -- Depends on what kind of tank -- Stainless Steel? Aluminum?

Don't bother if it's galvanized stamped steel.


I wash my tanks with Simple Green and water - about three times..... making sure to slosh this mixture around so it gets in the corners etc.

Then I rinse with plain water.... and sniff the tank... I don't want anything that even remotely smells like gas. IF the tank sniffs okay -- then I set it in the sun to bake and dry out. I've also done this with standing them up and directing some heat on them.... just to evaporate the water.

Before welding -- I get some dry ice and put that in side the tank -- I wait until the vapors are pouring out of all the openings. The dry ice turns into CO2... and purges the air out.

Add more dry ice if you need to as you weld and reposition etc.

What you don't want is any air in the tank -- it's the gas fumes that are explosive! If you've done your job washing... remember GAS is an oil so needs some soap of some kind to get it clean.... and you've got an inert gas -- then the fumes can't ignite.

[bigkarz]

dish soap works the radiator shop showed me

[rjardy]

Originally Posted by bigkarz

dish soap works the radiator shop showed me

Perfect! Thank you. The tank is a stamped one. I'm thinking it is probably galvanized. I have had good luck with muruatic acid to remove the galvanizing, any other tips on removing it? I know what happens when you weld it. (Ask the 20 year old me about that) so ill do my diligence in removing it.

Rob

[T_Raven]

I used the pump out of a 98 Camaro tank in my 67 GMC. I just needed a quick, cheap way to get the truck running so I put the Camaro pump in the stock, in cab GMC tank.

I filled the Camaro tank with water and cut the ring out



I filled the GMC tank with water and welded it in. It works fine until I get around to putting a tank under the bed.



A lot of people are really concerned about welding on a gas tank. It can't explode if water is displacing any fuel vapor. If there's a cheap option to just buy the tank you need, then that's not a bad idea, but I wouldn't be afraid to weld on a used tank.