Tig copper

bb1127 · Mon Mar 10, 2014 11:43 pm

Can anyone tell me why I'm getting craters when welding copper
It looks like I don't have the gas on but I do! Thanks in advance

NYWELDERJim · Mon Mar 10, 2014 11:51 pm

Hello, how does the molten puddle looks while welding? Is the puddle spitting when you melt it? IWhat type of parts are you welding: new copper bar stock or parts which has seen use and/or possible contamination? What are your welding conditions: gas type, flow, electrode type, AC or DC, etc.?

Jim

bb1127 · Tue Mar 11, 2014 12:04 am

The puddle looks like crap and it is spitting! I'm welding copper sheet that is new
I'm using helium and 1/8 tungsten dc and a flow of about 40cfh

Braehill · Tue Mar 11, 2014 1:08 am

I would be lying if I told you I knew anything about welding Copper but, it sounds like too low of a flow rate on your gas. Helium wants to rise out of the weld instead of blanketing it, so I'm thinking 60 cfh might be better. You might try adding 10-25% Argon to the Helium to stabilize the arc some, Argon ionizes better than Helium. You can do this with a wye fitting from a cylinder of each and it's best to use the ones with valves. The blend doesn't have to be perfect.

A lot of cylinder fill places will blend custom cylinders at a premium price if you choose to go that route. Since you've already bought Helium, you know it's not cheap. One more thing to note on Helium is that some cylinders are filled for filling balloons and have some Oxygen added for the nit wits that want to sound like Alvin the Chipmunk. That will wreak havoc on your welds.

Len

WerkSpace · Tue Mar 11, 2014 2:12 am

I'm going to have to try this with my plasma welder.
Apparently it works well on copper, but I've never tried it.
The plasma is 14400 degrees F versus acetylene's 6000 degrees F.
https://www.youtube.com/watch?v=xxhkqZ4a-e0

BTW - Watch out for those nasty fumes. (Metal Fume Fever)
http://www.aws.org/technical/facts/FACT-25.pdf
http://humanservices.alberta.ca/documen ... _ch032.pdf

coldman · Tue Mar 11, 2014 2:44 am

I have only fusion welded copper with argon. Never heard of helium being used. Puddle should be shiny and run quick in direction of torch travel. Pulsing is good too. Why are you using helium?

bb1127 · Tue Mar 11, 2014 8:25 am

The reason I'm using helium is bc I was told
If I was using argon I would be fighting a battle I couldn't win

coldman · Tue Mar 11, 2014 8:41 am

I can't say whether helium works on copper because I've never heard of it being used on copper. I can say that argon does work well because I have done it on sheet copper up to 3mm thick - outside corner, lap joint and tee. Also on thick bus bars for motor rewinders at high amps ( I can't remember how thick at least 1/4" and maybe 3/8". Flat bars together, TIG specified for deep penetration.)

I suggest you try with argon if you have access to it and compare results. DC is OK, Thoriated is OK (sharp point).

Maybe you got the recommendation based on the current capacity of your power source. What machine are you using?

bb1127 · Tue Mar 11, 2014 9:04 am

I'm using a dynasty 350

Bill Beauregard · Tue Mar 11, 2014 7:41 pm

I have only welded copper as an experiment. Metals and How To Weld Them from the James F. Lincoln Arc Welding Foundation, printed in 1954 and 1962 says that basic copper includes .05% oxygen in the form of copper oxide. at high temperature this oxygen separates from copper and combines with hydrogen, and carbon monoxide to form CO2 and water vapor, causing bubbles. as copper oxide melts at lower temperature, it migrates to the joint causing embrittlement.
De oxidized copper is suggested. The book recommends high amperage and high speed cooling again before much embrittlement can develop.

I'm anxious to know how you do, I want a copper top for my kitchen island.

Oscar · Tue Mar 11, 2014 8:50 pm

I just TIG'd some tiny copper tubes, ~1/8" OD, about ~0.020" wall. Argon works just fine for me. Granted there will be discoloration due to the heat sinking capability around the weld joint, but a quick brushing will take care of it. Pulse works great for this.

Wiredwelder · Wed Mar 12, 2014 11:27 am

I'm sure you have already done this, but are you using a ton of amps at startup? I welded a bunch of ground clamps together, (like 30 )that were 3/16 . On full power for my dynasty 200, the whole time! I was using 30% helium. Once it would puddle! it ran like butter!

Superiorwelding · Wed Mar 12, 2014 11:43 pm

bb1127,
This thread on TIG welding copper and the one on MIG welding copper has allowed me to dive deep into how this is done. For now I wanted to comment on the use of Helium and Argon. First, how thick is the material you are welding? This will determine what gas you should be using. Instead of copying out what AWS says, start on page 25-Welding Copper, and that should show you when you should/shouldn't use argon or helium.
http://www.copper.org/publications/pub_ ... /a1050.pdf
-Jonathan

Oscar · Thu Mar 13, 2014 11:47 am

Superiorwelding wrote:bb1127,
This thread on TIG welding copper and the one on MIG welding copper has allowed me to dive deep into how this is done. For now I wanted to comment on the use of Helium and Argon. First, how thick is the material you are welding? This will determine what gas you should be using. Instead of copying out what AWS says, start on page 25-Welding Copper, and that should show you when you should/shouldn't use argon or helium.
http://www.copper.org/publications/pub_ ... /a1050.pdf
-Jonathan

WOW, thank you very much for posting that link to that pdf file. I have only skimmed through half of it, and have learned a LOT about copper!

rahtreelimbs · Thu Mar 13, 2014 9:02 pm

I welded a small open corner joint on 1/8" copper plate. Used the same settings on the flow meter on the argon as I do on steel. I used some household copper wire as filler rod.

Don't know if this is the right way to go about this but it welded fine for me!!!