Welding aluminim diesel tank???

[LarryB]

I've blown up a gas tank or two not getting all the gasoline/fumes out. I've filled them with water to purge all gas before welding and they still go "WOOF!"



Question. Do I need to do the same thing with my 100 gal trailer aux diesel tank? I have a small pin hole that I need to weld up but don't really want to fill it with water. I'l be using my TIG. Seems like the diesel would be less explosive than gas, but then again, flight 800 blew up on Jet-A.

 

[Philip]

Buy some dry ice. Break it up and put it into the tank. This will remove the oxygen in the tank. CO2 doesn't promote burning. So anything left in the tank will not have the oxygen to burn. Or use a CO2 fire extinguisher if you have one around handy.

 

[catoiler]

Fill tank!

Fill the tank all the way and go ahead and weld diesel fuel does not explode like gas so with a full tank and no air it wont burn just make sure the fuel is cool. thats what do at work on our tanks.

 

[mikel]

If you go the dry ice route don't put the cap on the tank. In one of my more juvenile times I used to crush dry ice and put it in a plastic bottle then screw the lid on and lay it somewhere. About 3 minutes later it'd explode from the pressure build up. You wouldn't want that to happen to your tank.



As to welding on the tank I've seen people weld on full diesel tanks before without anything happening. I've also seen the local joker sneak up behind the welder with a bag and pop it, scaring the heck out of the welder.



Have fun,

Mike

 

[Philip]

mikel



I forgot about that part of it. oooppppsssss

 

[LarryB]

My problem with welding on the tank when it's full is that the pin hole is leaking. Looks like the dry ice or engine exhaust is the way for me. Or, how bout letting the TIG torch run Co2/Argon into the tank for a while. Will it lay in there or is it lighter than air? Mmmmm.

 

[Philip]

The argon would work. But the price of argon might get expensive. You could put the cap on the tank this way.



If you have two bottles of argon and regulators. I would set one up to feed constant. Then do the weld job as fast as you can.

 

[drees1]

I assume you would run straight Argon for aluminum? It is heaver than air and will stay in there pretty well. Even 25% CO2 Argon will stay in the bottom too.



Doug Rees

 

[rdrose]

argon the best way

my brother welds aluminum all day long. and repairs lots of aluminum tank. let the argon purge in the take for a few minutes and you should be just find.

P. S. when the tank is being welded the heat will show if there is more cracks near where your welding, like magic they just appear.

 

[LarryB]

Thanks guys for the advise. I emptied the tank, let the argon run in it for a few min then welded her up. No fire or nuttin.