Topic: MIG or TIG?

[rbmgf7]

I started on TIG before MIG. I had a guy teach me who TIG'ed for a few years. It's really not hard to lay a bead but it is hard to get good penetration and lay a good bead without excessive heat to your part.

My explination is going to be based on a professional welder (no, I'm not professional but it's what I was taught):

TIG has a lower heat affected zone (HAZ). It's the area surrounding your weld which changes composition from the heat. MIG tends to have a wider HAZ. In essence, HAZ isn't good since the rapid heating and cooling weakens the part just outside the weld. Usually what you'll want to do is anneal your part to relax it and restore it to it's near original state.

Most will debate TIG or MIG has better penetration. It's really dependent on the welders ability. If he knows how to weld, he could get great penetration and maintian a low HAZ with a MIG.

MIG is used in large scale manufaturing all the time since it's efficient. The automated machines are calibrated to give a good weld.

TIG is great because of it's adjustability. You have the ability to change electrode diameters for narrow or wide welds, pre and post flow, foot control, short wand extension for tight spaces, etc. Most TIGs are also AC which is needed for welding aluminum. TIG welding aluminum is a completely different ball game! Albeit, the price for a baseline TIG can get you a really good 220 MIG.

For sheet metal and thin walled tubing, I'd go with a TIG. For framework, exhaust welding, etc. a MIG will do fine.

[Kong]

Well, if you've ever done brazing with a gas torch and a brass rod you'll find TIG pretty easy, it is from the welder's point of view a very similar process.  I can't imagine anyone just starting with TiG; MIG is like baby steps on the way to learning TIG is the way I've always thought of it.

By the way, Lincoln in a wholly owned subsidiary of Miller. 

[rbmgf7]

I though Miller owned Hobart?

[Raef]

What welding process did Honda use to weld the CB frames?? My guess is MIG.

mine looks as if some of it could had been done with a torch, I can find no evidence it was done with a mig welder, especially the back bone and the sheet metal stamped gussets.

Mig is somewhat similar to stick welding in the respect that the heat is added using the filler metal as a conductor so sometime it is hard to get a good heat to filler ratio especially with inconsistent joints. This is why you sometime get the weld that don't stick, to much metal filler and not enough heat, dirty surface, or loss of shielding gas. We have 3 wire welders the biggest 220 unit is probably 30 years old, of the 2 smaller ones one is dual voltage and 1 is 110. I use the 110 unit the most and it works very well up to 1/4"

Tig welding and  Oxy acetylene torch welding are similar in the respect that you add heat then filler metal using the heat to draw the filler to the desired location. Tig is much easier than a torch but they both have a place. We use a torch for nearly all of our sheet metal work, I have recently started building aluminum stuff and I have been using a gas torch for that also

Mark