I have limited experience with "stick" welding. I have 220 Volts 50 Amps available. Having no TIG or MIG experience, I think a decent used stick machine would be best for my home & hobby use. I see used AC transformer welders advertised on Craigs List. Would I be better off holding out for an AC/DC machine?
Would it be practical to add a rectifier to an AC welder an an attempt to make it into a DC welder?
I have done some reading in this group and other sources. At the moment I am searching for a Miller Thunderbolt AC/DC, but am open to your advice and suggestions.
I am located in the San Diego, CA area.
Thanks in advance.
DC is much better, but AC can work.
A low end AC/DC machine costs so little is just not worth the trouble.
Good choice, but also look at the comparable Lincoln units.
If you want portability get a Miller Maxstar 150S for around $650.
Your benchmark for this class of machine is the 225 amp Lincoln 'Tombstone' welder http://www.mylincolnelectric.com/Catalog/equipmentdatasheet.asp?p$93 These can be had for around $250 brand new The AC/DC version http://www.mylincolnelectric.com/Catalog/equipmentdatasheet.asp?p$94 can be had for around $350 new The Miller 'Thunderbolt' are similar, just not as many out there at the hobbist/homeowner/farmer level
Lots of farm and hobbist welders using the AC versions, the DC version allows smoother welds, a few extra rod types. For a hobbist buying new, it's a tossup between AC only or AC/DC If you get a bit more advanced, want to run lo hydrogen rods or hardsurfacing, rods, get the DC option.
Used equipment is commonly avaialable. My local Craigslist has a constant stream of 180 to 225 amp stick welders in the $50 to $150 range. Most are AC only, many are old, most work fine. I would not be afraid to pick up a Craftsman or Airco welder if the price was right. Don't even think about the 120 volt versions.
Several of the guys have built diode stacks to convert the AC to DC. If you want a project, go ahead. Usually the cost of the 4 diodes and the reactor start pushing close to the difference in cost between the AC and and AC/DC machines. If you have an AC machine or get one cheap, it might be worth the time to build the diode bridge, heatsink, reactor, and cooling fan.
My personal preference is to find a used 180 to 225 amp 240 volt AC unit for around $100 with the cables, holder, and helmet. Try it out, learn to use it, buy something with more features later IF you need it. I see there was a Lincoln listed on your local craigslist under tools.
Ive got a nice Hobart 250 AC/DC machine, located in Costa Mesa (Newport Beach). True industrial machine. You will need to put some leads and a stinger and ground clamp on it though $200 Works just hunky dory. Might be able to dicker a bit on the price.
I believe its 200 amps at 60% duty cycle. Copper transformer.
Rule #35 "That which does not kill you, has made a huge tactical error"
Although there's nothing wrong with the "tombstone" welders by Lincoln and the equivalent Miller machines, they are limited to a 20% duty cycle.
If you're patient and persistent I'll wager you'll be able to find a deal on a Lincoln 250 amp "Ideal Arc" machine. The one you want is the AC/DC "round top" welder. Be careful because all kinds of machines were sold under the name "Idealarc".
These were legendary machines. There's a tremendous difference between the quality of a 150 amp and a 250 amp machine. The round top idealarc machines were built for heavy duty industrial / institutional use.
I own several stick welders. And this is my personal favorite.
IMHO, ALWAYS BUY MORE THAN YOU WILL NEED.
Otherwise, you will outgrow it soon, and be back in the market for a better one soon. I had a Thunderbolt, which I bought new. It was great, but had its limits regarding larger rods, or heavy duty cycle. But it is a good LITTLE machine.
AC welding is good for thicker metals, imho, if I have it right. When I want something to really really hold, I will stick it with 7018 stinger positive and crank up the power. I think it is better for all position welding than AC, or at least that is my experience.
Long story short, there will be times when you purposely want to use one or the other once you get experienced. Have that capability. Even if you buy the Tombstone Lincoln, get the AC/DC. I just don't like the jumps in amperage, but rather an infinitely variable setting. But that being said, the Tombstone is one hell of a machine for general purpose welding for the money. I believe there has been as much welding done with Tombstones as Pipeliners.
Shop around. You can buy a lot of machine for a pretty decent price in the used machine department. I think you will like the Thunderbolt, but will soon outgrow it if you weld much at all. You may have to bump up your electrical service, but that's no biggie.
Just mho based on my experience. Good luck.
Using a lincoln AC-225C stick welder here.
Its about half the size of the tombstone, which I owned several.
The AC225 weighs about 85 pounds.
Reason I got rid of the big tombstones... got real tired of moving them ...each "big real estate deal" then move on to a better home...
I know you can put wheels on them, carts, etc....but man, they are still heavy suckers....
You always want to buy the biggest machine you can afford. But when was the last time a hobbist needed to burn 3/16" rod for hours on end?? That's the only time the 20% duty cycle comes into play. I do the usual trailers, Jeep bumpers, trailer hitches with 1/8" rod and some occasional 5/32"
The OP has "limited experience" wants to do "home and hobby" useage. Point him towards something he can use the first day right out of the box.
Steve B wrote:
You said it all in the first sentence. And for the same amount of money, you can buy a bigger better used machine. Sure, a guy can some machines first day right out of the box. What about second day when he wants to kick it up a notch?
The 'You" in my last post was referring to Steve B as someone who always says buy the biggest and best and most expensive. The OP is a hobbist, get a hobbist grade machine.
I've bought used and helped some newbies get used machines. It's always dicey. My last unit cost $5 but it needed cables, connectors, new jacks, work on the amperage selector, and didn't come with a helmet. It sat in my 'do something with it' pile until it came back to life on a cold winter evening. I'd NEVER tell a newbie to go buy a unit in that shape even if it was a good unit and just needed accessories. They would never get it running.
A friend said he needed a basic buzz box, had missed out on one for $100. I ran across a nice used one with a kart included for $50. My buddy was at work, I just bought it on the spot. For a while it was looking like a would get to have ANOTHER welder around here as he hemmed and hawed that the unit I had was not EXACTLY like he had looked at.
Steve B wrote:
Yeah but once you start pushing that 20% duty cycle it drops off to about 5%. I have a few larger industrial machines, but have a little shoebox wire feed that runs on 115VAC for semi-remote tack jobs. Stick it back together until you can get the job close to a real welder. Even for that, 20% DC gets annoying real fast.
The shoebox cost me $20, and that's about all it's worth. A "real" welder doesn't cost that much more and can do so much more.
I've run my old 180 amp buzz box for hours on end, steady welding with 1/8" rod on custom bumpers made from 1/8" wall tube. Probably running something like 60% to 70% duty cycle at 110 amps. Welder warmed up but not anywhere near it's limit. So where do you get this 20% duty cycle going down to 5%? Granted, the manufactuers used underrated diode assemblies so you can't get decent power out for DC but that is true all the way up the line until you get to 3 phase equipment.
Wasn't necessarily referring to your welder....
Some of these little new welders that have a Duty cycle rating of 20% can barely maintain that. My little Sears shoebox being one of them. After about 2 minutes of welding it drops out. If I don't wait for it to cool back down, it drops out again. Quicker and quicker.
The point really was, as others have made, don't buy a toy. Buy the biggest welder you can afford and pay attention to the DC ratings. Anything that uses a 10-20% DC rating to get 100 amps is going to disappoint and be incredibly frustrating to learn with.
I do most of my welding with either of my Millers or a Thermal Arc, but they aren't very portable for those remote "make it work" jobs. My big welders have 100% DC ratings up to about 250A, which I rarely ever deal with.
I've welded with a Miller Thunderbolt since the 1980s and only a couple of times have I ever run into duty cycle limits. The thing is, when I'm making something, it's not just welding, it's cutting, fitting, clamping, tacking, checking, measureing, correcting, and only THEN welding, usually for a few inches. Then go on to something else. However, one time I had to weld up some 3/4" plate with a full vee. That was a PITA with a 20% duty cycle welder. But one time in 20 years isn't all that bad.
You have to factor in the fact that a home shop welder has to be moved, and it has to be stored. A heavy industrial welder is tough to move, nearly impossible if steps are involved, and requires a lot of storage space. Also, DialArc machines run around $400 used on the West Coast, and buzzbox units are often $75, and the difference can be meaningful for a lot of hobbyists. Arguably you'd get better results in saving the difference and spending it on a real good autodark welding hood, where the visibility would be so improved, your welds would look much better.