Hickey said:
How much welding have you done in the past? They are telling you to start with scrap steel, so you don't fawk up your Jeep. A welder is not like a wrench, it's not a good idea to just go out ad buy one and start boogerin up your rig.
Here's an idea, make yourself a swingout tire carrier. BBowski did and excellent write up on the one he built. You can get the parts you need at Rocklogic.
Thanks Hickey, I'll do a search for his writeup.
To answer your questions, I actually took a welding class
before I decided to buy my welder. I'm still an amateur/beginner, and have about 100 hours behind the gun. My beads look good with good penetration, and I realize that I need more practice. I am careful and safety-concious. I didn't mean to give everybody the idea that I really just went out and bought a welder and wanted to start welding on anything metal that moves. I thought the WINK smiley would convey my sarchasm, but apparently it was missed.
I have already boogered up my Jeep anyway.
(note the wink, everybody)
I installed a hockey-puck lift (another joke, it was a body lift kit). A couple of "nuts" stripped and so I had to cut open the floorboards, weld in some nuts and weld the floorpan back together. It turned out well. I also welded a brace onto my rear axle:
http://www.rockymountainextreme.com/showthread.php?t=9121
So, this is the extent of what I've done on the Jeep with the welder.
EDIT: I found his post about the carrier, but didn't see a complete writeup, although there's some good info in there and that carrier looks nice -- I like the design.
http://www.rockymountainextreme.com/showthread.php?t=2694&highlight=tire+carrier