carbon arc torch questions

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Hi, BACKGROUND: I recently built a carbon arc torch which I have been using with my WWII-era Marquette stick machine that weights 300 something pounds. Here's a vid on first tryout, I've made some additional improvements:2 QUESTIONS:1: I've seen a number of videos on folks making spot welders from old microwave ovens like this dude:So is my carbon arc torch basically doing what his spot welder is doing? Or does the microwave put out DC volts and my carbon arc AC?2. I've also seen a number of folks building solder resistance stations using car chargers and stuff like that. This pdf seems to be the most popular one visited:http://www.nmia.com/~vrbass/models/solderer.pdfSo can my carbon arc torch be used for resistance soldering for brass and copper or will I need to build a separate resistance soldering station?I have so many projects planned that I don't want to create a redundant device.Thanks much in advance for your info/suggestionsDaveDave VUSMC '74-'95South Bend 9A lathe 1942Marquette stick welder, oxy/acy, FCAWBuild 7/8 scale trains
Reply:A proper spot welder puts out a very high current at low voltage. They can be AC or DC.  My Dayton (Miller) spot welder puts out around 6,000 Amps.  It's AC.A welder transformer is designed to limit short-circuit current, so it's not suitable for spot welding. (Unless you want to spot weld a rod to your workpiece )  The modified microwave transformers have the current limiting shunts removed.For resistance soldering, I would stick with a DC battery charger like the article you posted."USMCPOP" First-born son: KIA  Iraq 1/26/05Syncrowave 250 w/ Coolmate 3Dialarc 250, Idealarc 250SP-175 +Firepower TIG 160S (gave the TA 161 STL to the son)Lincwelder AC180C (1952)Victor & Smith O/A torchesMiller spot welder
Reply:thanks, so just lowering the amps on the stick welder/carbon arc torch attached won't do what a microwave transformer can do for the fellow who posted the video of his homemade spot welder.Dave VUSMC '74-'95South Bend 9A lathe 1942Marquette stick welder, oxy/acy, FCAWBuild 7/8 scale trains
Reply:I have an original Lincoln carbon arc unit. It has two electrodes that are brought together to make an arc. That way you have a constant arc. I have used mine to braze, silver solder and to heat metal for bending. I don't think that you could steel weld with one since the arc is not small enough. They were very economical since no gas is needed. I've never seen one with only one electrode. I built a resistance soldering unit that I have used  for soldering brass model railroad parts and it has only one electrode but it doesn't generate a flame, only heat when touched to grounded metal. Here's a picture of the Lincoln carbon arc torch. They run very nicely on 80 amps and the size of the flame is easily adjustable depending on how far apart you set the electrodes. Lincoln quit making them about ten years ago and they always get snapped up on eBay. Miller Millermatic 252Miller Syncrowave 200Liincoln AC-DC 225Victor O-A Set
Reply:Originally Posted by SE18... so just lowering the amps on the stick welder/carbon arc torch attached won't do what a microwave transformer can do ...
Reply:Thanks for explanation oldendum, your'e always helpfulgnm, nice set you got there. I made mine b/c every time I went on eBay to buy one, someone with the right software would snap em up at last second, so yeah, guess they're still in high demand. I'll do some brazing this weekend with mineDave VUSMC '74-'95South Bend 9A lathe 1942Marquette stick welder, oxy/acy, FCAWBuild 7/8 scale trains
Reply:Dave,  keep an eye open for old AC welders for sale in your area.  Sometimes you'll see an old Forney or Marquette or Wards welder that has a carbon arc torch.  Maybe you can buy just the torch.\Also be on the lookout for a spot welder.  I stumbled on a little-used Dayton badged welder that is actually a Miller LMSW-52.  Gave $75. for it.  They sell for $650. + new.Last edited by Oldendum; 11-14-2013 at 09:18 AM."USMCPOP" First-born son: KIA  Iraq 1/26/05Syncrowave 250 w/ Coolmate 3Dialarc 250, Idealarc 250SP-175 +Firepower TIG 160S (gave the TA 161 STL to the son)Lincwelder AC180C (1952)Victor & Smith O/A torchesMiller spot welder
Reply:Three more days on this one.......http://www.ebay.com/itm/LINCOLN-CARB...item19e4d1413bor.............make your own. http://www.instructables.com/id/Make...volt-stick-we/Here's one in action. Last edited by gnm109; 11-14-2013 at 10:32 AM.Miller Millermatic 252Miller Syncrowave 200Liincoln AC-DC 225Victor O-A Set