Cart for PA160-STH
Once I got my PA160-STH, I decided that I really needed a dedicated welding cart, so that I could keep the welder attached to the argon cylinder when I moved it around. I do all my welding on my back carport, but it's not covered, so I have to move my equipment back into the basement when I'm done. So I'm constantly moving the welder in and out.
Here, you can see the basic design of the cart. Three shelves with wheels in back and casters in front. I also put two pieces of 2" tubing on, to hold containers of TIG filler wire. I built the cart out of 1" square tubing, more because I like the way square tubing looks than anything else. It certainly would have been strong enough if the shelves had been built out of angle iron. Tubing is also pretty easy to weld up.
When I first started planning the build, I decided to stick-weld the whole thing, because I didn't have very much TIG experience under my belt--having just bought the PA160. But after I got the material home, I couldn't resist firing up the TIG torch. I realize that, for a more experienced welder, 1" square by 1/8" thick tubing would be no big deal to weld up with stick, but I find it a little challenging, especially because there are such short runs to make your welds, so if you start or end the bead just 1/8" short, you actually lose a significant portion of your weld. I really appreciated the ability to have more control of the weld with TIG, especially because I was just a few inches from the weldment, instead of 14" away on the end of a stick electrode.
Here are a couple of my first TIG welds. Nothing to write home about, but not bird-poop either! I had trouble feeding enough filler, and you can see the weld is a little concave as a result. I was using 1/16" filler, and since then I have gotten better at feeding it more quickly, but I recently also just got some 3/32" filler that I'm going to give a try. Especially as a beginner, I can get more consistent results with the lay-wire technique, but of course I have to have the right size filler.
When I was shopping for the welder, I was a little torn between the PA160-STH and the PA200. I wasn't sure whether the TIG pedal would make that much of a difference. Now that I have it, I'm sure glad I got it. Obviously, people make good welds with fixed-output, scratch-start TIG all the time, but the ability to roll onto and off of the heat is pretty nice. It's a good learning tool to see how the different heat inputs affect the puddle and the resulting weld in real time.
As careful as I was with my fitup, I had a lot of problems with warpage to deal with. To make matters worse, I don't own a heating torch, so the best methods of correcting the warpage aren't available to me. I had a small issue with the bottom "cupping" up where I welded the uprights on. The uprights themselves cupped when I welded the middle shelf on. And, as you can see, the middle shelf was all sorts of wonky. I tried using clamps and a hydraulic bottle jack to straighten the material cold, but it didn't really work. I would have had to do a lot more bending than I was comfortable with.
I ended up correcting most of the warpage by welding U-shaped beads onto the back of the tubing with my TIG torch. It was important to weld up the corners as well as across the face, or it didn't straighten much. Someone suggested spraying down the piece with a mister bottle after welding, to increase the effect of the weld. I do NOT recommend this. The entire piece rusted to heck, and I had to spend about an hour grinding it clean, which is why it is so shiny in this photo. What a dumb idea. If I had had a torch, I could have dried the piece thoroughly after misting it, but if I had had a torch, I wouldn't be doing this in the first place.
As you can see in the photos above, the middle shelf is still a bit crooked, but overall things are much better than they were. I decided to leave well enough alone.
Finishing the project was delayed because I had to go to the steel supplier and pick up a sheet of expanded metal. I used expanded metal for the shelves, as well as the bottom of the TIG filler tubes. I didn't put solid bottoms on the TIG filler tubes because I didn't want them to collect dirt, and I also didn't have any thin scrap, and didn't want to spend a bunch of time and effort cutting out a piece of thicker scrap. The hole saw worked fine on the expanded metal once I clamped it to a piece of wood as a backer-plate. I was really thankful for my PA160-STH when I was welding the expanded metal to the 16-gauge tubing. No way I could have done that with stick!
... and now I am out of photos for this post, so I am going to continue in another post.
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