TIG or MIG Welding

[Karlo]

For those that have more experience than I, what is your preference and why?

[cheapracer]

MIG, fast, cheap and if understood, strong.

TIG is slow, expensive (based on time), often very neat and if misunderstood, weak.

Arc is best but slow, messy and often ugly.

ARC adds to the existing metal, MIG etches into it and TIG adds, but can make steel brittle locally.

At the very edges of a MIG weld on say 1mm thick steel, the thickness can be reduced to 0.9 to 0.95 mm there - have a close look for yourself, maybe even the chair you are sitting on is MIG'ed. You will never find a lightweight thin walled motorcycle frame MIG welded for this reason - they are either TIG'ed or braze welded and when your chair is old and breaks it will be along the edge I mentioned.

Most things are MIG'ed because it's so fast and no cleaning up afterwards, economics.

I MIG my chassis's but I have a top quality MIG welder used at practicle settings (voltage and feed), I use the best quality feed wire but most importantly I use an expensive exotic gas mix rather than the cheap common 100% CO2 - great results, sometimes it's true, a workman is only as good as his tools.

[CMC#5]

For the garage hobbyist, the best answer is Mig. Its cheaper, easier to learn, easier to produce quality welds, and its versatile enough. Tig hardware is much much more expensive, and requires much much more practice before you're welds are good. Note I ignore the time it takes to prep/execute in the garage because its just not that big a concern when you're not making hundreds of welds per day, but even there Mig has the advantage over Tig. Arc is out IMHO since it isnt capable of doing the fine work you will likely run into in the garage.

Hell, at one point I made a tube frame for an off road buggy using chrome alloy and...oxy-acetilene. Hey, it was what we had available! Point is, anything will work given enough care and practice (and post weld heat treating!!! ;) ) but for tinkerers Mig is the way to go.

[Karlo]

Point is, anything will work given enough care and practice (and post weld heat treating!!! ;) ) but for tinkerers Mig is the way to go.

post weld heat treating. What is that??

[CMC#5]

Post weld heat treating is a generic term for a procedure employed to undo bad things that welding does. More specifically, it entails heating the affected area to a specific temperature and then cooling to ambient at a specific rate in order to achieve desired hardness of both the base and weld materials, as well as relieving stresses created in the welded assembly due to stretching/shrinking of heated/cooled metal.

Some materials are very prone to hardening (or softening!) when heated and cooled rapidly. Also, metal expands when heated and shrinks when cooled. Welding does all of this. So, the specific welding technicque, filler material (welding rod), as well as PRE and POST weld heat treating are all parts of a good welding procedure in order to avoid things like brittle welds, brittle base metal, internal stresses (that later become cracks) etc.

The vast majority of this can be ignored whith some materials, but some are pretty finicky.