Hi
I am looking to get into doing my own tig welding. I have stick, mig and torches, I am not new to welding but have never done tig. I want to buy a small machine only to work on guns nothing else. I was wondering if I can get some advice on what to look for, there seems to be a lot of different options and I'm just starting my education on this.
Thanks for any advice, Tom
I've used a bunch of machines. I'm a gunsmith as well. The features I consider the most important on a TIG rig for gunsmithing are:
- HF start. Lift start and scratch start might be OK on pipe or other TIG jobs, but they're not acceptable (IMO) on gun welding.
- steady arc at low currents - being able to adjust the arc down as low as a 1 to 4 amps is something you will find useful.
- Adjustable pre-flow/post-flow on the argon.
- A good welder should allow you to weld two razor blades together, edge to edge. If you can't control the arc down to the point where you can weld two razor blades together without blowing through the blades, you'll find yourself making a mess of some smaller gun parts. Last time I did this to demo my machine to someone, I had it down to 4 amps.
- pulse control. This is optional IMO on plain or alloy steel. On smaller stainless pieces, pulse control is very useful. It is useful on aluminum as well, but you if you work on only guns, you probably won't be welding aluminum.
- as others indicated, a water cooled torch is very, very useful. There's nothing more annoying than having to stop because the torch gets too hot to handle.
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I've used the following TIG rigs:
- a Thermal Arc 185, and if I were looking at a TIG-only machine, I'd give the TA machines a look. The 185 seemed weak when I used it for stick welding.
- Lincoln's Invertec 160 (a solid enough little DC machine, but with a limited duty cycle). Never tried to use it for anything but TIG. It was great on plain and alloy steel and only OK on stainless.
- Lincoln's Precision TIG 225 (a very solid and capable machine), good as a stick source. It has basic pulse control and AC balance.
- Lincoln's Precision TIG 275, which is a hulking beast of a machine, adjustable down to 4 amps, as I recall. It had the balls to weld some seriously deep/thick material. Never used it for stick, but I see no reason why it wouldn't do well as a stick machine.
- Miller Syncrowave 200's and 250's. These are very solid machines, but pretty large. These are a very solid value in the used market.
Want to compare a bunch of machines at your leisure for a few hundred bucks? Take a TIG welding class at a local community college. When I wanted to learn to weld well and kick the tires on a bunch of machines, that's what I did. I got to try more welding rigs than you're ever likely to be able to do at any dealer's shop. The local college has machines from Miller, Lincoln, ESAB, Thermal Arc, and has power sources for stick, MIG, TIG, submerged arc, dual shield, air arcing, etc. They had one Dynasty 200 when I took the TIG class, it was brand new to the school back then, and the complexity of the machine put off most of the kids. Being a retired engineer, I had no problems with the Dynasty's complexity, and after I invested the time to learn the what pulse shaping can do for a TIG machine, I came to really like the Dynasty more than all the other machines, especially on thin stainless. When you're welding stainless, it is possible to heat the material surrounding the welding bead to a point where the chromium comes out of solution. This appears as a black, grainy area where the stainless got too hot on the back side of the weld or in the area surrounding the bead. It is called "sugaring" because it looks about like what sugar looks like when you burn it. Once you sugar stainless, it's done and ruined.
Pulse control helps prevent this type of problem in stainless.
I ended up buying a Dynasty 200 with a liquid cooled torch.
Other things you'll need for TIG:
- a way to sharpen your electrodes. A green wheel on a grinder works well. Use it for nothing other than sharpening tungstens.
- ways to clean the parts to be welded to be very clean. In TIG welding, cleanliness is success. Don't try to weld through any kind of oil film at all.
- Some way to steady your hands. Holding a long arc means putting lots of heat where you don't need it. I use various rests made of wood on which I rest my wrists. Sometimes, I'm trying to hold an arc length of 1/32nd or less.