I have a 80 aluminum J valve scuba tank that I would like to use as my welding tank for my Hobart 187 mig welder.
Does anyone know if this tank will work? I am sure I have to change the valve set up. If so what do I have to do to modify it?

 

I don't think they'll let you. At the place I get gas, they have all of the same sizes, small, medium and large, and you just exchange it every time. So I don't think they'd fill it up.

 

Do not count on having it filled anywhere...unless its compressed air.
You might get lucky and be able to trade it in for a shield gas tank (likely Gold mixture).

 

YEah i dont see why you wouldnt be able to but like was said nobody will fill it. Use it for OBA instead

 

Welding. Do it right and rent or buy the appropriate tank. No one will fill that tank with shielding gas cause most places won't fill a tank that is not theirs due to legal ramifications.

OBA is another story.

Get a big full size tank if you can afford it. Typically you only get maybe 4 hours of welding time out of the 80 cu ones. I just call my local shop when out and they bring one by work and swap it out.

 

The answer is NO. Use it for OBA or sell it. Its better to rent tanks cause they need to be recert every 5-8 years(?). Although a scuba tank is strong enough, no one will fill it.