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Something New to be Bad at

March 26th, 2017

TIG!

I am finally a TIG welder. The results so far are pretty hilarious.

TIG, for people who, unlike me, are not experts, is Tungsten Inert Gas welding. Without getting into a boring description, I will just say that it’s probably the coolest type of welding outside of bizarre things they only do at NASA. TIG produces very controlled, good-looking welds, and unlike MIG, it works very well on tiny objects.

I got myself a Chinese TIG machine because the company that makes them had a crazy sale, and I could not resist. I couldn’t find a good deal on a used American job, and I figured if the Chinese one blew up, there was a 75% chance I could fix it with my gnarly electronics skills.

The welder sat around for three weeks or so because I was scared of it. You can teach someone how to MIG (badly) in fifteen minutes. TIG is way more complicated, and it’s somewhat harder to do. It took me three days just to get the machine put together. I suppose it would have been more like an hour if I had stuck with it, but every time I figured some part of it out, I felt like I needed a day to rest and get over it.

When you TIG, generally, you will do three things at once. Your foot will regulate the heat you shoot into the weld. Your right hand will direct the arc from the torch to the workpiece. Your left hand will feed a rod of filler metal into the weld. This takes practice.

Yesterday I decided to use the torch without filler, just to see if I could guide the arc correctly on flat steel and make a molten puddle suitable for a weld. I was just learning to use the foot pedal and torch.

I had read that TIG produced more UV light than MIG. That’s not quite correct (of course, it’s more complicated than that), so I took pains to get advice on protective gear. I usually MIG in shorts and a T-shirt, which is a BAD BAD idea, but TIG scares me, so I asked around. I ended up wearing a helmet, safety glasses, a dress shirt, a T-shirt, gloves…and shorts. Come on. Change is hard.

When you MIG, you can weld metal that’s only fairly clean. You remove the paint and crap, and you hit it with a knot wheel to make sure there is no rust or scale on it, and you’re okay. TIG metal has to be cleaner. You have to get every trace of rust and scale off, and you have to wipe it down with a powerful solvent like acetone. If you stop welding and come back the next day, you will have to clean it again before you start. If you weld aluminum, you even have to worry about the invisible layer of oxide that forms the instant you expose new metal to the air.

I decided to use a crappy old piece of angle iron, which is a lumpy product that comes covered with scale that seems as hard as rubies. I had to use the belt grinder to get it clean.

I put all my protective junk on and started TIGing. It was so easy! I was liquifying the metal and pulling the torch along, and it was almost like I knew what I was doing. I figured I would be a TIG prodigy. Then I saw the bright light coming in under my helmet.

With all the neurotic effort to protect myself, I had still forgotten to close the helmet tightly against my chest, so reflected UV was bouncing off of my shirt. And of course, I looked right at it, which was pretty dumb.

I stopped TIGing instantly, went and sat on the couch, and whimpered a lot. I wondered if I had burned my corneas.

When you let welding UV hit your eyeballs, even if the UV is reflected off of walls and such, you may burn your eyes. It doesn’t cause permanent damage, but for a day or so, you feel like someone threw sand in your eyes. This is something I dread. I have never “flashed myself,” as the expression goes, but I’m absent-minded, so I live in fear of the day when I start to weld without closing my helmet.

If you flash yourself, you start to feel it after a few hours. I never felt anything. Maybe the safety glasses saved me. Maybe the light wasn’t that intense. Anyway, I was really happy about that.

Today I started over. I prepared two pieces of angle iron and clamped them at 90 degrees to each other so I could do a couple of fillet welds. A fillet weld unites two pieces of metal which are perpendicular to each other. You have to weld down in the corner.

I had high hopes, based on my success with the puddle, but things went very badly. When you TIG into a corner (I now know), it can be hard to get the arc to go where you need it to go. Both pieces of metal try to pull the arc toward them and away from the corner. I think. Anyhow, the arc kept moving around. When I concentrated on the arc, I forgot the pedal, and the amps dropped off to where I was just tickling the steel. When I thought about the arc and the pedal, I forgot about the filler and rammed it into the tungsten (part of the torch that makes the arc).

In about fifteen minutes of welding, I had to grind a new tip on the tungsten three times, so now I’m an expert at that.

The welds were horrific. I’ll post a photo. It looks like a string of poops from a steel mouse with dysentery.

Since creating this masterpiece, I’ve realized you don’t begin your TIG efforts with fillet welds. I’ll try a butt or lap weld next time. Or an autogenous (no filler) fillet weld. That’s supposed to be good for beginners. And I won’t use angle iron. I’ll find something better somewhere.

I quit after a short time because I wanted to see how the protective gear had worked. I think I was protected well enough, but if not, I would rather have 15 minutes’ worth of burns than an hour’s worth.

In spite of this disaster, I’m very upbeat about TIG. Once I can control all three parts of the apparatus at once, I’ll be able to do welding which is much more precise than MIG. Also, for reasons I do not understand, I can see what I’m doing much better than I do when I MIG. With MIG, all I see is a giant red blob.

I like the machine a lot. It looks very nice by Chinese standards, and everything (except me) works. I should be able to get years of use out of it.

Here’s my guess: if you want to weld fast, get stick or MIG, but if you want to weld really well, get a TIG. But get ready for a learning curve.

I’ll keep the world posted on my bad welding. I should be back at it tomorrow or Tuesday.

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