tig welding copper

[muddstopper]

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.

 

[Morning Wood]

Always thought it was soldered or brazed.

 

[Shield Arc]

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!

 

[tommu56]

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

 

[muddstopper]

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.

 

[dstig1]

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.

 

[Creamer]

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.

 

[yomax4]

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...

 

[muddstopper]

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.

 

[k0ua]

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

 

[yomax4]

Sure..Regular copper wire will work it just contains oxides that copper generally doesn't like as far as for high pressure, x-ray, corrosives etc. I have used electrical wire in a pinch as well but if you do any large amounts you will appreciate the de-ox.

 

[tommu56]

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.

We were set up to do aluminum I didn't even look to see were it was just adjusted it to work It was a miller sincrowave 250XD so it was less than 250 :laughing:but I use scratch start and the foot pedal for control. so it is hard to say.

tom

 

[dstig1]

A couple of keys - you should have an AC welder just like for aluminum. The high conductivity metals weld better with this.

Ummm, no. Read the Miller link. DCEN with 100% Argon. AC is generally only for alum and mag, AFAIK.

I have head electrical wire is fine filler for most work, though I am only repeating what I've read....never tried it, though I would like to.

 

[weldermike]

I recently welded up some copper, it was strictly ornamental and needed to be ground, blended and polished with colors matching. It was 28gauge and the only filler I had on hand was some #6 house wire. I took some real focus but I was able to pull it off. I used dcen straight argon, and dont hold me to it, but I think I had the machine over 100amps, copper can take some heat! Merry Christmas guys!

 

[muddstopper]

Mike, I had seen your post before about welding the copper. Its kind of what has given me the ideal to try it. A question I have for you, I have read that when welding copper that you concentrate the heat on the rod more than the piece to be welded. Did you find this to be true,

 

[weldermike]

Yes, in a way I did find it to be true. The instant that I would start my arc I had that filler right on it in the argon flow and instantly balling up and using the arc to break off that molten ball so to speak, then I would just stay with it like that, just breaking off one molten ball after the next. What took so much focus was trying to keep my giant filler as close to my tungsten as possible while still maintaining the tiniest closest arc as possible and keep repeating the balling and breaking off. If my base metal was thicker and I was a little more prepared with correct tungsten and filler I think it would have been just like using silicon bronze, that was kind of like the feel it had. I would say tho that my method was definately not textbook, and I was just winging it, LOL. Hope that helped a little bud!

 

[muddstopper]

I believe you said you used #6 wire, I am wondering if a smaller gauge such as #12 or #14 would be easier to work with. I have a truck project in my shop right now thats taking up all my room. As soon as the truck is out I plan on playing around with some copper fittings for practice before starting the real thing. My project is a solar water heater. Yea, I know I can use solder for this, but I am wanting to do this with the tig because my next project will require more skill than I currently have, and copper is pretty expensive to be screwing up. Practice, practice, practice. I appreciate all and any advice given.

 

[TxDoc]

Jody at weldingtipsandtricks.com posted some info on tig welding copper with some helpful tips:

TIG Copper Welding



And, Kevin Caron posted a copper tig welding video recently:

How to TIG Weld Copper - Kevin Caron - YouTube

Just to throw in, Jody did a video on tig welding brass, never seen that before.

How to Tig Weld Brass - A Tig Welding Brass Repair Job - YouTube
Hope that helps

 

[Danno1]

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I TIG welded some Monel (Cu-Ni alloy) eyeglass frames once. I cut phosphor bronze sheet into strips to use as a filler rod (since that's what I had). I was pleasantly surprised at how good it came out. Saved money on new frames!


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