I would like to do my own MIG (?) welding, mostly for sheet metal on my 71 F100. I've never welded before!! What welder should I start with or stay away from. Do I need the gas or not. There are so many out there. Any help will be appreciated.

 

First, MIG stands for "metal inert gas" so yes you will need a tank of argon, CO2 or some blend of gas which precludes oxygen around the weld . What you will need will depend on your expirience level and the manufacturer's recomendations.
As far as welders go, you can pick up reasonably inexpensive models anywhere that will do pretty well or go with one of the big names like Lincoln or Miller, that choice is yours and depends on your budget. Have you considered renting one maybe? That may allow you to use a nicer machine than you could have bought for yourself and give better results to boot.
*One biggie though, If you've never used a welder get lots of the same material like you will be working on and practice with it until you're comfortable with your work before you start zipping on your truck. Once you've made a sizable mistake on thin body panels it's a *itch to correct so practice, practice practice.
If you have the bucks and are going to use a welder enough to justify having one, my personal preference would be a Miller or a Lincoln and a 75/25 blend.

Steve

 

I like Lincoln and Miller. I have a Millermatic 130 XP I use for light-duty stuff and I'm very happy with it. The wire feed never jams. If you want cleaner, stronger welds, use the tank. Or get used to uglier, weaker beads and cleaning the tip a lot more. Shielding gas also reduces or eliminates spatter (and so does proper surface prep). You'll know you have a good bead going when it sounds like frying bacon. Usually it's a CO2/argon mix (75% CO2), but for welding aluminum you want pure argon. Some aluminum alloys like a He/Ar mix (75% helium) to inhibit magnesium oxide formation, which will weaken the bead. Aluminum, like cast iron, should be preheated first to avoid cracking. You can even use oxy-acetylene on aluminum reliably if you can find blue cobalt lenses...

I have a Lincoln AC/DC 220v buzz box I use for the heavy stuff, but unless you want to use a stitch tip for sheet metal (Eastwood carries 'em), the MIG is the best bet. When doing sheet metal, you don't want to weld in a continuous line, because you'll warp the panel. 1/2"-1" skip-welded beads are better. On floor pans, who cares, unless you're restoring something valuable like an old 'Vette or Ferrari. I recommend picking up a copy of "The Welder's Handbook" by Richard Finch, it'll point you down the right track.

I think I'm gonna eventually spring for a Miller Synchrowave TIG setup, with a footpedal (being good with a wah-wah pedal on the guitar helps)...

 

you know, i've never seen a vette with metal floor pans.