The Home Machinist!

I had a real scare today. I thought I was running into the consequences of buying Chinese. The welder would not shut down when I let go of the pedal. Turned out I had it set for a hand trigger. I didn't know a TIG trigger was different from a MIG trigger, which shuts down instantly when you release it. For other noobs, a TIG trigger stays on after you push it. To stop, you have to push it a second time.

I took my pedal apart and everything.

I finally got the machine figured out, and I worked on aluminum. I wanted to do steel, but when I asked my supplier if he had pickled and oiled, he said they could ORDER it. Man. This must be the worst town on earth for people who use tools. I bought seven feet of 1/8" x 2" aluminum and cut it in small pieces for lap welds.

Here is my best aluminum effort yet. I finally got a handle on torch angle and arc length. They were causing tremendous problems. I did a lot better this time, and I only jammed the electrode into the puddle once. On this particular weld.

I can't believe how fast I have to go on aluminum. It flies. If I hesitate at all, it blows out.

I could not deal with the ends of the welds. With a trigger, it was impossible to weld them without blowing out. With the pedal, it was better, but not good.

I figure my aluminum will run out after one more day.

I discovered a good way to get rid of mill scale. You let the steel rust. The rust knocks the scale off, and then you use a flap wheel or something to get rid of the rust. The rust is way easier to remove than scale.

I welded my hand a couple of times today. I did not know that was possible. Didn't die or anything.

Wow, I envy you. I've been trying to make time to refamiliarize myself with TIG for a year now. I thought it would be an ideal thing to fool with while I recuperated from my new knees, but that didn't happen either. From the looks of your latest welds, you are at or nearing the skill range I was when I stopped ~30 years ago (only MIG since). I never could do very well on aluminum, results of a simple lap would have looked maybe a little better (in my perhaps over generous memory), but not much. I could make nice welds in steel, but nothing like most of my family (career welders, boilermakers, pipe fitters, etc). But I got my TIG about a year or so ago and quickly discovered that not only had I lost whatever skill I had, but just can't seem to get the coordination back, so looks like I'm going to have to start over from base principals to get my issues sorted. I'm thinking I should see if my local supplier has suitable coupon stock on hand. Maybe if I get it in here so I can just sit down and play I'll finally get it done. All my structural steel requires cleaning, and that combined with too many projects and not enough time is usually enough to make me put it off for another day.

Anyway, full props to ya' for getting down to business and sticking with it. Keep at it, and maybe you'll encourage me to follow in you steps...

Thanks, and for God's sake, don't start with aluminum. Not unless it's thick, anyway. This thin stuff is treacherous.

The forum at Weldingtipsandtricks.com is fantastic. I recommend it. It's the opposite of PM. Nobody will give you a hard time.

One of the things they taught me was to practice rod-feeding in my spare time. I have extended that. I practice all of the welding motions with the machine turned off. I don't do it enough, but I think it's a good idea.

I think I'm good enough to do simple steel welds on real parts, but I would be nervous about welds over two inches long in visible areas.

BTW, my LED sewing light from China works great for welding.

Oh, I well know (remember) the perils of aluminum. It seemed I could never really "see" the puddle, or more or less just a change in reflective gloss. So I never could do thin aluminum with any confidence, I doubt I could do it at all now (currently too bad to even be worth a try).

I think that's likely the core of my problem, lack of practice. I keep stabbing my filler into the edge of the puddle and sticking it, or getting it too close to the electrode, or even getting too focused on the filler and getting the electrode into the puddle. I think if I could just sit down and spend an hour or so, most of the basic skills would come back. But I'm not sure how much more I may have forgotten, or never known (largely self taught in spite of family skills), so I've been thinking about taking a welding class at the local CC. Problem is, the only way they teach it is with an initial class on all the theory followed by a broad survey of all common processes. I'm sure there are important things for me to learn, but that's a lot of time spent on things I already know (enough for my needs) and processes I'm not interested in learning. So back to short on time and long on projects, another thing not pursued...

That cheap light made a world of difference in what I could see.

That's a pretty good run you had going there!

Thanks. I think next time I'll try to get thicker aluminum that doesn't melt as fast.

One man's thin is another man's thick...

Most of my aluminum welding is .032" to .063".

Stick with the 1/8", as you are doing fine with it.

SteveHGraham wrote:That cheap light made a world of difference in what I could see.

Tell us more about the light?

Look up my post about puck lights. I talked about it there. It was about $11, I think. Not all that bright, but it worked for me today.

SteveHGraham wrote:...The welder would not shut down when I let go of the pedal. Turned out I had it set for a hand trigger. I didn't know a TIG trigger was different from a MIG trigger, which shuts down instantly when you release it. For other noobs, a TIG trigger stays on after you push it. To stop, you have to push it a second time.

Sounds like you have the welder in 4-touch (4T) mode. When using a trigger switch, instead of a foot pedal, it can be either 2-touch or 4-touch mode (depending on the machine). The 2T mode starts the arc when you press the trigger and stops the arc when you release. 4T starts the arc with the first press and release, stops the arc on the second press/release. This is usually programmable on the newer machine as the 2T or 4T option.

If you can program 4T mode, it can be used to approximate a foot pedal. So, for example, you could set up the machine so that in 4T the first press starts the arc, quickly ramping up to 120A for your initial puddling. When you release the switch it drops back to 90A and you proceed down your weld. At the end of the weld you press the switch again and the arc ramps down to 15A over several seconds, and then the arc completely stops when yon release the switch again.

In 2T mode it is just on/off. Without ramping or active current management with a pedal, blowouts and end cratering can be a problem, particularly in lighter gauge materials. If your doing the same welds over and over, 4T gives you a way to repeat the same current profile over and over, once you have figured out the optimal setup.

I figure my aluminum will run out after one more day.

Eh, take two welded plates and place them in a tee joint. That gives you another set of fillet joints to practice. Then take two tees and put them together to form a box, that gives you a couple outside joints.

I discovered a good way to get rid of mill scale. You let the steel rust. The rust knocks the scale off, and then you use a flap wheel or something to get rid of the rust. The rust is way easier to remove than scale.

I recently heard another method, haven't tried it yet. Supposedly, if you soak the parts in vinegar overnight, the scale when loosen and come right off with a sander or flap wheel.

choprboy wrote:I recently heard another method, haven't tried it yet. Supposedly, if you soak the parts in vinegar overnight, the scale when loosen and come right off with a sander or flap wheel.

It works, and works even faster if you add some common rock salt.

Harold