</font><font color="blue" class="small">( Great idea to use bedrails - the attic is full of them. Yugo )</font>
Well..I thought so too. Untill I tried to drill holes in it. My drill press was mostly useless as it undoubtedly was too fast. I bought new titanium bits, used old bits, broke new bits, etc etc. The only thing I could seem to do was drill a 3/16" pilot hole with my 1/2 drill motor. I needed about a 3/8 inch hole. I finally gave up and went next door for the plasma cutter. Wish I had one of those, but they arent cheap.
Be glad to give you any "beginners" advice, but it will be totally from a few experiences and absolutely no other knowledge. Best I can offer at the moment is, GO SLOW...watch your puddle, get your penetration, and get plenty of wire in your weld. Try to make it a nice, flowing continuous weld by going slow enough that you don't have to backtrack. At first I thought the recommended wire speed was too fast, but after a little learning realized it was actually too slow, and I had to bump it up a half a notch or so. Clean all rust and paint off first if at all possible as you absolutely need a good ground, and clamp it close to your working area.
Get you a lot of good wide mouth vice type clamps, a set of welding magnets are handy(all at Homier.com....cheap!), a self darkening hood (TSC $59), and a good vice (Harbor Frieght $39). Keep a set of small wire dikes in your pocket for cutting off the long runout wire till you get the hang of "buzzing" it off. Also, my Homier angle grinder, and portable ban saw were cheap and have been VERY handy. If at all possible, go with the Argon mixed gas with your mig. A lot cleaner welding with less splatter.
Best of luck, you will thoroughly enjoy it.