Welding Copper

[Hillbillysmith]

Anyone here ever welded copper?? Did you use a special copper filler wire/rod? I also know you can use a SS filler rod. I believe it's 318, but don't quote me on that. Did you TIG weld it? MIG weld it? O/A weld it? But I highly doubt SMAW was used, but if so, did you use that??

Since you can weld copper with a SS filler, has anyone ever welded copper to stainless or visa versa? Anyone ever thought of doing this? I think it would look kinda cool on those repousee's that I see people making. Anybody????

[welder19]

never welded it per say just soldered it but I would imagine it could be welded.

welder19

[irnsrgn]

It's tig welded often for extending buss bars in large electrical applications. In Thailand when I was in the SeaBees, we ran out of bronzing rod and I used stripped copper electric wire with brazing flux as a substitute till we finally got some.

[LDW]

The Nobility of Common Metals


1. Aluminum
2. Zinc
3. Steel
4. Iron
5. Stainless Steel - Active
6. Tin
7. Lead
8. Copper
9. Stainless Steel - Passive


When dissimilar metals are in contact with one another in the presence of an electrolyte, galvanic action occurs, resulting in the deterioration of the metal with the lower galvanic number. The electrolyte may be rain water running from one surface to another, or moisture from the air containing enough acid to cause it to act as an electrolyte.

The company I work for made some large copper sailboats one time that had stainless rods welded to them representing the ropes running down each mass. After a while the galvanic reaction caused the stainless rods to start falling off, I had to replace the stainless rods with copper rods. The rods were attached to the copper with phos- copper brazing rods.

[John B]

By SS, did you mean Silver Solder or Stainless Steel?

Copper can be silver soldered to join pieces, and the silver solder can also be used as an inlay to provide decoration on other materials also.

[ThomasPowers]

You can tig weld copper, using a piece of the original is suggested for the filler to get good colour match.

[Thomas Dean]

I used to weld 316L S/S strips, 2"x 1/8", to 11ga. 4'x8' copper sheets. Used "dioxide copper" bare wire with BayState 13 flux using the TIG process. There were 20 sheets of this to line an alcohol reactor. The stainless strips were then welded to the inside wall and the long seams were welded. (We made 200proof ethal alcohol). This and 99.997% pure silver was used to protect the inside of the reactor walls. The reactor was 7" thick. The acid used in this process was so hot that it would attack every metal except the copper and silver. (all the S/S was covered with copper). If you are welding thick, 1/4" and up, it will save you a lot of heartache by using 100% Helium as you purge gas. Doing so you will be able to cut your welding amperage to less than 1/2 when using argon. BTW, we never had the stainless turn loose from the copper. The grade of copper and stainles may attribute to this. This process, alcohol, was run at 1250psi with 750*F, this was the reason the acid would attach so vicious. (at least that is what the engineers told me)

[evfreek]

Last night I tried welding copper with TIG. I did not use any flux. Would brazing flux help? The project was the one on Ron Reil's www pages:

Gallery
Making Copper Wire Bracelets

The process was not very controllable, and I was successful only by striking an arc, then immediately stopping as soon as I saw a shimmer. The welds ended up looking pretty clean, but the copper dripping off got oxidized pretty badly.

Does one commonly use a paste flux? My welding books don't seem to cover copper. Only steel, stainless, aluminum and titanium. No flux.

[Joe H]

I've TIG'ed copper several times. It welds nice. It fuses well with no filler, if you need filler a strip of the base material or a piece of copper wire works well.

I wouldn't think brazing flux would help, probably just make lots of nasty smoke. The argon shield should be all you need.

[agsolder]

james gonzalez posted a picture of a nifty copper garden vessel that he made as a first raising project in the coppersmithing section here just a few days ago, said it had involved some welding. I queried asking him how he had welded it, and he replied: with his Lincoln 300 TIG. Perhaps james could amplify.

[james gonzalez]

As far as the copper welding goes, I just went down to the welding shop and bought copper filler rod.
I am sure I could have used bits of scrap but I like visiting the welding shop. They might have to special order it in your area.
I did not particularly like the way it flowed, But the final weld held up well during the raising process despite the fact that I am a fair to middling tig welder at best.
I did have to do a little pinhole filling at the end there.
Maybe try using a thick sacrificial plate next to where you want to make the weld. You can start the arc there and have time to look around and adjust the heat with the pedal before moving over to the thin stuff.

[evfreek]

Hi James. Thanks for the tip. And others about the flux. The copper fused well without flux. I like the idea about the nearby plate, or just a sacrificial welding table like HWooldridge's (I just bought one of those; if it gets goofed up, I will just get another.) I used scrap Romex as filler. It seems to work. The key for me was to keep the bundle of strands together (with another copper wire). If one gets loose, it is like the weak animal which falls behind. It gets eaten by the mountain lion

My welder does not have a foot pedal. I really need to get one. Maybe that's my next project. Or is it a guillotine tool. Or is it a new slitter, or shear or ... :D

[evfreek]

Here are some pics of the bracelet:

[Dr Dean]

Hey Evfreak looking good. What do you have for a welder? I might be able to help you out with the foot pedal issue.

[evfreek]

Hi Dr. Dean. Thanks for the compliment. My buddy who is into small stuff turned me on to this design. He swore off the big stuff after I passed off a 7/8" S-7 bar to him to break down into a knife.

The welder I used to do the ends of the bracelet is my homemade microwave oven welder. It uses the frame, rewound transformer, bypass capacitor, fan and plug from the oven. I "borrowed" an arc starter from a real TIG welder.

I have a paper bag containing a high current isolated triac, a diac, and a sheet aluminum heatsink. I need to fab up a foot pedal. Right now, I am working out the bang-bang to make sure I don't skip cycle or glitch. Also, I need to size the potentiometer, since a lot of these designs sink a lot of power (like the Miller pedal).

[Dr Dean]

Wow man you are way more ambitious than I am. Cool to hear about something like that working out for you. How about some pictures?
I have a fingertip control with my tig torch. One thing that I noticed is it's very difficult to actually change the amperage setting when welding. I'm saving for a foot pedal.

[evfreek]

Hi Dr. Dean. Here are the pics you requested . The arc starter is not homemade, but the welder is made out of an old microwave oven. GE Spacesaver, I believe :cool:

[Dr Dean]

Oh my, that makes me wonder if Dr Suess was on the design team.

[evfreek]

Hi Dr. Dean. Dr. Seuss is pretty funny, but I wouldn't trust him for building electronics equipment

I guess that I need to put a front panel and terminal block on that thing. But, if you are looking at it and trying to decide, decent panel or copper bracelet, the bracelet wins. I think that the next thing it is calling out for is a foot pedal. I just bought a bench shear. It works great and I look forward to using it. Maybe this will be good for fabbing a foot pedal. Just some string and a little slide. Weld it up with the homemade TIG. Should be good. I really miss the foot pedal on thin stuff, so that might come before the lugs and decent cables. Good thing I'm in no hurry ;)