tig welding copper

   / tig welding copper #1  

muddstopper

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I am wanting to try to tig weld some copper pipe. It will be polished so i dont want to use anything like silver solder, or any of the other lead free solders or the phosphorous bronze rods. I am sort of new to tig and have been searching the internet for videos. What I have learned so far is that it should be done DCEN using de=oxyenated filler rods and pretty high heat. But no one seems to give anything as to a proper starting point for how much amperage to run. Pipe will be 3in type L pumbing pipe. Exact thickness is around 16gauge. Have to go back and look again to make sure exact thickness. Anyways, for those that have experience in tig welding copper, I could use a few tips on how to start. I have a lincoln 250/250 amp stick tig machine with foot controls and plenty of 100%argon for a gas. I wil be practicing on 1/2copper tube before I try the expensive 3in pipe.
 
   / tig welding copper #2  
Always thought it was soldered or brazed.
 
   / tig welding copper #3  
I've never done it myself, but have read where guys use DCEN, 2% thoriated tungsten, and 100% helium. Supposedly it welds some what like steel, but has a wetter more flowing puddle. And takes a lot of amps!
 
   / tig welding copper #4  
I miss ordered for a job at work once and we were doing the job on a Sunday with 2" Copper

I had to fasten 2 1 1/2 fittings together and didn't have any tube cleaned them and clamped them together uses pure tungsten reverse polarity and heilum and used solid electrical wire as filler.

I practiced on some 3/4 fittings to get my heat and to check the rod (solid electric wire ~ 12 gauge) the rod melted at a little lower melting point than the copper.

Back to the 1 1/2" tacked in 4 places just by fusing it no extra rod. removed the clamps and did 1/8 of one side rotated it 180 did another 1/8 back to first side back and forth till it was all the way around polished up with some scotchbrite the other guys were running the other pipe while I was doing this when I brought it back they were amazed because they didn't know you could tig copper (I didn't tell them I didn't know it could be done either until I tried)


tom
 
   / tig welding copper
  • Thread Starter
#5  
Tom, what kind of amp setting did you have to use. Everybody says high, but what is high. Is helium really necessary, Everything I have read suggest 100%argon.
 
   / tig welding copper #6  
Miller - TIG Welding Calculator

Select copper and go from there! There is a mobile friendly site for this too, and you can buy the old cardboard sliders for a nominal fee too. Get the set of all 3 (MIG, TIG, Stick) if you buy them as it is dirt cheap.
 
   / tig welding copper #7  
A couple of keys - you should have an AC welder just like for aluminum. The high conductivity metals weld better with this. Also, it depends on the rod. you can use electrical wire but there are some bronze rods that diffuse better and are easier to weld with.
 
   / tig welding copper #8  
If you have a foot control or hand amptrol you can set the high at about 200 and run from what ever the low output is up to 200 amps. This will get you from cold to way hot with no problem.. You definately want to use de-ox copper filler for sure. If I remember from the old days, The 250/250 does not turn down very low and is a transformer machine so you need to be careful. All tig I have ever done was electrode negative and this application will work good with Argon. It's all in the filler metal. It has to be de-ox copper. ( deoxidized copper ) Available in small qty. From Harris or a distributor. I did some de-ox copper on a stick of cleaned and capped tubing. Just be sure to melt the filler at the same time or before the base melts. Flows like honey but goes away as fast as bronze or aluminum...
 
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   / tig welding copper
  • Thread Starter
#9  
I guess I will just hook it up and see what she does. I will probalby start with just copper wire and a few copper fittings until I get the feel of it and then move up to the de-ox wire. No use in spending money on high dollar rods until I find out if I can do it.
 
   / tig welding copper #10  
I guess I will just hook it up and see what she does. I will probalby start with just copper wire and a few copper fittings until I get the feel of it and then move up to the de-ox wire. No use in spending money on high dollar rods until I find out if I can do it.

You can do it. It seems to work well, I just used Argon, DCEN and copper wire for filler... It seemed easy to me. I did not try to weld anything critical, just junk copper.

James K0UA
 

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