I have some experience gas welding and a bit more experience replacing sheet metal on an MGB with a decent quality mig welder. I'm getting things in line to build a locost and am considering taking a course in welding and purchasing the equipment. I'm also not sure that the terms are the same between the UK and the US. There is MIG, TIG, Stick, and other types of welders. What would be most valuable for chassis building and what are the specs for a welder that would meet the requirements. If I know this now, I can start cruising ebay. There is a lot of junk for sale and I need something that will work properly without compromise. By the time I start this project, I should be able to get in a lot of practice. In any educational course, I'd like to know in advance what sort of questions to ask before I sign up.

Welcome to the mad house.

A decent quality MIG will do almost everything you need for building the chassis.

Just stay away from the cheap crappy ones.

As you are in the US you ought to look at the Lincoln SP range. I have one (SP170)here in the UK and its a cracking bit of kit and a doddle to weld with.

They are good value, but you would need a 240volt outlet in your garage for anything more than an SP140

http://www.weldingmart.com/Qstore/p003797.htm

http://www.weldingmart.com/Qstore/p003799.htm
David

[Edited on 15/12/09 by flak monkey]

Don’t underestimate the cost of renting gas, it can easily amount to quite a lot and if you’re not going to be using the welder much then consider using gasless MIG wire. If you do still go for gas, do make sure you turn off the bottle at the main valve after using as otherwise it will just bleed away.

Using MIG is good news for me. I've replace a fair percentage of an MGB GT chassis using a MIG and at one point, the car was actually in two pieces that you could walk through -- the car nearly got me divorced. I got to the point where it became a matter of the sound of the welding became the indicator that the joint was going to be decent. There's a nice tone of frying sausages in fat... The welding course is still a good idea. They sell the Lincolns at our local DIY store. The current Lincoln website shows the 180C MIG welder and I assume that this model is similar to the SP170. Ebay for a new 180C is around $900. I'm going to assume that the best economy is to use gas which frees you to buy regular wire instead of flux coated wire which probably costs an arm and a leg. I know nothing about argon but I do keep compressed CO2 for my homebrew beer. I'll see if my CO2 supplier can get me argon. I'm also off to make friends with someone owning a plasma cutter.

I've always wanted to have a welding rig anyway. A few years ago my boys and I attached a pair of broken skis to the bare wheels of our lawn tractor and put chains and weights on the rear wheels. It was great fun in the snow towing kids around on cardboard box sheets until the skis broke beyond repair. A welder would have made the contraption awesome.
Thank you much for the replys.

The best gas for mild steel is a mix of Argon plus a small amount of CO2 and O2. In the UK a typical one would be Argoshield Light from BOC. I'm sure that the US suppliers will have something similar.

Mind you, CO2 is fine, as long as you don't mind a bit of spatter clean-up afterwards (it's a bit hotter too).