Anyone here have a preference on what type of current limiting their AC welding machines use, or the open circuit voltage that it has?
This is my first post on this group. Let me explain why I am posting this.
My primary welding box around home was a cheep cambel hausafeld 50/70A stick welder. It uses a current limiting transformer with an open circuit voltage of around 33V What relation it's rated current settings on the switch had to the actual current on the electrode is anyone's guess..... I have cussed at it many a time. Striking and holding an arc with it is very hard. Almost impossible if you don't have nice dry rod......... But I have to admit that there is a lot of stuff running around that is still in one piece because of it.
I had hoped that a higher end stick welding machine would be easer to use. Those hopes were dashed when I used a miller thunderbird XL at a neighbor's garage. I hoped that it would hold a better arc with a 80V open circuit voltage. Needless to say...... I did plenty of cussing at many a stuck electrode and lost arc with it. It didn't handle much better than my little old CH 50/70 welder. Unless the rod is right out of a freshly opend pack, you are in for a lot of agony. You have a lot more current, but that is about it.
About a week ago I was helping another neighbor with a track loader. he ask me to check out his welder because it quit working. I followed him into the shed to take a look. There was two welders there. I ask him which one. He said that he wanted me to check out the new one. The other one in the corner was an old one that he was going to throw out, but he just hadn't got to it yet.
The cover was off the old welder and I could see down inside it. It had a massive transformer inductor setup. A lot of heavy iron.
I said "No no no, don't throw it away, I'll take it, just load it up in the van"
Checked the new welder and got it working again. Loaded up the old one in the van. He told me that the reason he was throwing away the old one is he couldn't find cable plugs that would fit it. So he was just wanting rid of it.
It is an old forney CBBT. It weighs over 200 pounds. It has welding current settings from 5 to 250A. What fascinated me was it's method of current limiting. It uses a big multi tap inductor/reactor across the top for current limiting. you select welding current by what tap you connect to on the inductor (socket on the front panel) The OCV is 80V I made up some new cables. I home made the cable plugs with some 3/8 copper pipe. The home made plugs fit nice and tight.
I hade an idea that it may hold an arc better because it uses a series inductor for current limiting instead of a current limiting transformer.
When I played with it for the first time I was just using an assortment of old damp welding rods. I figured I would see how badly it would do with the worst rod I had. I was astonished!!!!!!!! An old rod with mildew on it struck on the first tap and burnt without break from start to end!!!!!
I found that I could stretch out the arc to lengths I could only dream about with the miller. One rod I used had the coating broke off the top half. I was just planning on burning off the bottom half and throw it away when the arc died after the last of the coating burnt away. The point came where the last of the coating disappeared, but I kept on laying bead. Welding with a bare electrode on an AC welder was a new one for me. I haven't tried using a completely bare electrode to see if I can start and hold an arc with one. That is something I will have to try tomorrow.
With new rod the only problem I should have if falling asleep while laying bead. :-)
Am I in a alternate reality, or is a machine with an inductor/reactor for current limiting really that much better at holding an arc than one with a constant current transformer (transformer with magnetic shunts)?
What other machines out there use a multitap inductor or variable inductor (in series with the transformer output) for current limiting?
Why don't I see modern AC machines with that type of setup? One reason I can think of is the cost of a separate 80V at 250A transformer and a large series inductor. Did a mention that the thing weighs over 200 pounds? Over twice the weight of a Hobart stickmate 235A welder.
Needless to say, I don't think I am going to be getting rid of it any time soon! Now if I can just find other welders that are easy to use as it is.
Am I nuts or is there anything to what I am seeing?
Or is there welders with current limiting transformers that can hold a solid reliable arc even with old and damp rod?