Bottom line if you do just a little bit of online study, and know what a good weld looks like, you can teach yourself to weld.
It just takes practice (welding table). You have to burn up some rod/wire and spend some time doing it. You will make all the common mistakes several times and learn the little tricks. The few that stump you will be answered a dozen times on the welding forums.
If you have someone in the area that has a MIG and can set one up invite them over for a couple hours and have them get the box dialed in so you know the settings are in the ball park, and they can critique your first few minutes of welding. Once you get the wire loaded in the machine, realize it feeds wire much better if you keep the holder/feed as straight as practical, the rest is just eye hand coordination, that takes practice.
When I first learned to weld my metal shop teacher (who did professional welding on the side) had us cut two, 1 inch round bars a foot long, tack weld them together and tack them to the welding table at a 45 degree angle, and we spent the next few days filling in both sides of the bars until they were flat. He then cut the bars in slices and looked at the welds. If we had no slag inclusions and good penetration we passed the arc welding requirement. This was with a 220 amp stick welder.
On the Mig when I got it, after tacking together enough of the welding table to have something to work with I did the same thing with some short segments of the 1/8x1 inch bars. Tack welded two short pieces together and ran a bead down the butt joint on one side, and then put them in the vice and bent them 90 degrees with a hammer at the weld line, to test penetration.
When I got good enough penetration that I could not break the weld like that, and could see penetration all the way into the joint I just finished the table by welding those strips on to form the top. By the time I had welded 4-6 ft of butt joint I had the basic feel of the machine, and I could start playing with settings and different positions for the wire and different hand motions to see how things worked.
A couple months ago I did a similar welding 101 class for a friend after he bought a similar welder and in about 2 hours he was doing acceptable welds in horizontal and low angle butt joints. It helped him a lot to just watch me weld a few inches so he could get a sense of the hand motion used, the position I held the welder with respect to the work and what the arc sounds like when you are doing it right.
For non-critical fabrication in the shop, self teaching is perfectly adequate and anyone who knows what a good weld looks like and has a little mechanical skill and reasonable hand eye coordination can learn the basics in a couple hours and become a capable welder by the time they burn up a good part of a spool of weld wire. (and periodically test themselves)
If you doing something critical, don't be afraid to make up some test coupons to practice on and be sure you are making good welds. An occasional self test will keep you honest, and ensure your self teaching is moving in the right direction.
Then once you get where you can handle 1/8 inch stock move to 16GA and learn not to blow holes in it, then do the same with 20 GA, and you will be able to handle 95% of the welding needed in a shop.
Larry
