AC vs DC Welder question

[EdK]

Now oxy acetylene is the one piece of welding gear I do have and have had for 25 years. I really like gas welding which is probably why I've always been attracted to tig - even if I've no legitimate purpose for it!

 

[jimg]

Hi Ed,
If you take the class youll be miles ahead b/c you start out gas welding. I enjoyed gas welding and like you am drawn to TIG b/c its a cleaner finer process. Its also very versatile. I think TIG can be just as all purpose as stick just not as fast. If speed doesnt matter then I would pick TIG. The results are far better. Theres no slag to chip or contaminate over welds and it doesnt put off all the smoke, fumes and spatters.

LOL! Our intro class had a one night TIG overview. Of all things the instructor chose Al to weld. Needless to say he spent a lot of time changing electrodes. Almost everyone drew Al up on the Tungsten...only a little touch down would do it too.

 

[SPIKER]

I prefer welding SS and AL with the TIG for sure, different tungstens , ever try SS with an AL tungenstin? lol. one was in the mach, all ready ground down so I thought it was SS red tungesten. needless to say it didn't hold up too long. anyhwo way my hands shake anymore I'm using the tungsten for filler material as much as I am for welding! /forums/images/graemlins/frown.gif

it is almost caulming welding SS with tig though, as long as you're back don't cramp up from some ackward setting postion!
Mark M /forums/images/graemlins/cool.gif

 

[Yankee]

I like TIG too, and agree that if you don't need speed it can be regarded as all-purpose for fabrication. For repair, though, it has one drawback in that you need clean metal. Fortunately, CC power supplies can run stick for dirty and rusty metal.

Yankee Bill

 

[jimg]

Hey, theres always a bright side to everything...Id look at that shake as the door way to a distinctive weave. /forums/images/graemlins/smile.gif

 

[jimg]

Right, TIG needs a clean start, However, many stick rods need the same. Only those rated for greasy, rusty, dirty parts will really give a good weld. I think the flux on them is designed to float out the garbage that wasnt cleaned up and to dig thru it as well. I suppose you could set the dig up on your welder but I wouldnt trust the resulting weld exc for noncritical joints. In all the repairs Ive done theres not been a time I havent been able to clean it up prior to welding. Ive always had the luxury of not being under a time dead line. /forums/images/graemlins/smile.gif

 

[EdK]

I noticed Rat came to prefer the Lincoln after thoroughly checking out the Miller Trailblazer and Legend. Mind filling me in on what it was that won you over to Red?

You other guys are inspiring me to hold out for TIG!

Ed

 

[jimg]

If you decide to go w/ a generator and welder (separate pieces of equip) have a look at the inverter boxes. The Miller Maxstar family is pretty slick. You get stick and TIG in the same box, portability and loads of control.

 

[EdK]

The only thing that has me a bit worried about the inverters is the reliability issue. It is a pretty expensive thing to start with and I'm hearing typical repair costs on the order of 50% of the purchase price. /forums/images/graemlins/shocked.gif

I know they're efficient with respect to power consumption however I already am set up with pretty heavy service in my garage to support a transformer unit. So the only downside to one of them would be the ongoing cost of the juice. Given my hobby orientation I don't suppose that would really be a factor as is quoted for inverters in production shop environments.

Do you find the Maxstar heavy enough for tractor attachment type welding?

I suppose reasoning this out fundamentally would permit me to get a generator-only unit now, saving the fine details of the welder issue for later - perhaps even after I've had the opportunity to taker a class or two. If that's the case then so much for the kill two birds with one stone aspect of the welder/generator.

Thanks, Ed

 

[jimg]

Hi Ed,
Understood about repair cost. They (Millers) do come w/ a 2yr parts/labor warranty. I think this should cover you pretty well b/c anything thats going to let go will likely happen in the warranty period....well usually. That said I asked my instructors and it was their view that todays inverters are very robust. In fact the Linde, Miller and Lincoln inverters at the school have required as much repair as the old transformer types....nearly none. So, the technology and design must be pretty good by now. Those units at school are heavily used too. During the normal yr theyre running between 8:00 and 9:00 (day and night classes) every day. If youre really interested to know you can give Jack (dept head) a call some time and ask him. He's a really nice guy and is very willing to answer questions.

Given your intended use I agree that power consumption wont be an issue. However, portability might be. If you can get your tractor/implements close enough to your shop w/o moving the welder then go w/ something less expensive (than an inverter). However, if you think you'll need it in the field or you want better controls (arc, gas, etc) the inverter might be what you want.

Yes, my Maxstar is plenty. Its a 200a welder but a 300a model is also avilable. I *think* the spec on the 200 is something like 3/8" plate in a single pass. However, thicker bits can be welded nicely multipass.

I dont want to come off sounding like inverters are the only solution. A good engine driven welder would certainly be portable (in a truck or trailer) and most larger units are multiprocess. I suppose it really comes down more to what you want to do w/ it and where. I'd drop by a MaineOxy or Merriam-Graves and grab the Miller/Lincoln catalogs. They contain lots good info. Probably the best source of info is the sci.engr.joining.welding news group.

Taking the intro class will help greatly in making an informed choice. The knowledge and hands on w/ differing brands and machines is invaluable. The experience you gain can't be replaced by any amt of reading.

jimg