The extreme outback pictured is the same I run only in 12v, If you have 24v handy you can run a readywelder too.

http://readywelder.com/

Works really good

Damn! That's pretty cool! Only about $500-$600 too. I'll definitely be putting one of these on the list.

Think I'll have to upgrade the alternator to the 400A version first though.

Thanks for the info on it!

Sent you a PM with a couple questions on your setup, by the way.

Keep an eye on CL and ebay, I found a new one on CL for $250. Alternator is not really part of the equation. Bigger is probably better though. You should have batts disconnected or isolated when welding, same as when welding on any vehicle. I run two batts on 12vdc, one as a back up that can be brought on line with a switch to give extra pull while winching or self jump if main gets too low. When I need to weld,  I use a 24v "yoke" to convert to series (24v) from parallel (12v) with anderson connectors. The way shown in pic is 12vdc, when in 24vdc configuraton, yellow QC's are tied together and out to readywelder.

Don't have 24 volts handy for ReadyWelder you can always run it with a Premier Power Welder.

http://www.premierpowerwelder.com/

I too have the Extreme Outback with a 4 gal tank. On 40" tires and wish I had a bigger tank, but the compressor is going on 10 years and it hasn't given me any issues.

I do have a leak somewhere though and dead batteries are a PIA.

Viar and probably others have tire size ratings with their stuff.



My tj runs little 31 inch tires and I mostly wanted the air tank for quick top off of tires, let compressor catch up as I move from tire to tire, or for the tank to run an air tool for a very short  time, like an impact gun for lug nuts or something.



Some of the stuff mentioned like the ac compressor modifications don't even need a tank, they usually flow enough a tank is just a restriction in the system.  Could depend on how you do it.



My stepvan runs 19.5 inch tires at high pressure so I am looking at something more serious for it perhaps, probably going to go with a house air compressor and a generator though since it is more a tool box/storage shed right now than anything else.



The little viar portable thing I have that just clips to the battery terminals is great for stuff like my ford or jeep where I think the max allowed tire pressure is 40psi.



This basically goes from really simple to really complicated depending how you want to do it, and also expensive.



Since I want a bigger house air compressor and already have a few generators running around it becomes ok to use that for something like the stepvan, and then I can look at a portable tank I refill with that compressor and wind up with about what tj was talking about.



Same can go for tire plugs.  Plugging something like an old lawn mower tire, riding mower type, vs the jeep or ford vs the 19.5 inch tires on that step van really show the cheap plug tools on up to the serious plug tools and what you can get away with.