tig copper?

Date 08-07-2012 22:30

It has a lot of thermal conductivity so it can be a challenge for welding. It would be easier to TIG braze with a silicon bronze filler wire. One brand is called Everdure.

OB

By Cumminsguy71 (*****)

Date 08-07-2012 23:16

Do a search on here lucky, I think there is another thread on this if I remember right. I have not tried tig'n copper but have done some tig brazing with the silicone bronze.

By OBEWAN

Date 08-08-2012 01:20

Yes there is another thread. This question comes up often. I have used silicon bronze to join copper to stainless. It is not too difficult.

By Tommyjoking (****)

Date 08-08-2012 01:39 Edited 08-08-2012 01:42

It can also be joined using SS filler 308/321/347 But remember the joint is only as strong as the copper itself...after all that heating most all coppers become excruciatingly soft....like it isn't already. Using the bronze is definitely a better bet because of the melting temps, the bronze melts at a lower temp then the copper where as SS melts at a much higher temp. Tig welding with the bronze will produce some smoke and some funny colors but it is definitely doable. The SS will weld very cleanly but you will might be shocked at the amperage required to make it go. With the bronze you can simply heat the copper and make it suck into your joints just like your brazing...if it is a lap weld it will be very strong. Good luck with it.

By 803056

Date 08-08-2012 03:13

You need to purchase deoxidized copper if you want a weld that isn't full of porosity.

Tough pitch copper will look like sponge if you try to weld it due to the high level of oxygen in solution.

High preheat and high amperage is required. The high preheat will increase the width of the base metal that will be "annealed" if the copper is cold worked for increased strength.

As can be expected, the end use will influence the decision to weld, braze, or solder the joint.

Best regards - Al

By welderbrent (*****)

Date 08-08-2012 14:42

I was trying all night (well, maybe not ALL night) to remember what I used on a job back about 16 years ago. Seems like it was as Al suggested and was an actual copper filler. We also experimented with all settings to see rather we preferred AC or DC to run. But my memory just isn't that good.

But Al hit it on the head saying "the end use will influence the decision to weld, braze, or solder the joint". There are advantages and disadvantages to each method/process combination. You and your customer's usage will be the determining factor.

Have a Great Day, Brent

By TAC

Date 08-08-2012 15:31

Used to reweld ~1/4" copper backing strips onto vise grips frequently. We'd strip some copper wire as filler. If memory serves DCEN works best, although it can be done AC. Be patient, it will take a while to heat the copper sufficiently.

Good luck.

By lucky1

Date 08-08-2012 17:47

thanks for all the info guys, i did do a search, i had thaught that i saw it befor too but i couldn't find it. thanks again, now its off to see if i can make a mess :grin:

By TRC

Date 08-09-2012 13:24

Deox copper, straight helium, dcen, 2% thor, big water cooled torch

By Stringer (***)

Date 08-10-2012 16:41

+1 TRC

By welderbrent (*****)

Date 08-10-2012 18:11

TRC,

Everything sounds familiar as to what we may have done years ago except one thing...So, a question. Why the Helium instead of pure Argon? Seems like we used Argon but I can't swear to it. What would the difference be in penetration? Arc characteristics? and other considerations.

Have a Great Day, Brent

By 46.00

Date 08-10-2012 20:11

For most thin section copper welds, Argon shielding gas is perfectly adequate. However, when trying to weld thicker sections or joints with difficult geometry, the advantage of the increased heat input of Helium when trying to fuse copper will become evident. Penetration would be offset by the increased thickness of the joint and arc characteristics would not be really different to be noticed,cost would prop be the most noticeable consideration!

By welderbrent (*****)

Date 08-10-2012 20:24

Thanks 46.00,

That's what I wanted to know. No more than I would use it in my circles I will probably forget it before I get to use it but it is still good to know and maybe someone reading this can make quick and good application of the information.

Have a Great Day, Brent

By Lawrence (*****)

Date 08-10-2012 23:04

46 makes a strong point.

Helium is an advantage.

But that advantage may or may not be reasonable, depending on things like thickness and number of welds required.

If I were making hundreds/thousands of welds, Helium could be worth the trouble, even on sheet or gauge thicknesses. Also there are thicker sections or complex castings where a GTAW weld just might not be made without He. That little punch He gives can make a big difference sometimes.

On the other hand if I have a short run or just a couple of welds that are non-critical.. GTAW with Argon is perfectly fine.

By DaveBoyer (*****)

Date 08-11-2012 01:46 Edited 08-11-2012 01:49

Since HELIUM has been mentioned, what is the availability situation for all of You in various arieas ?

My friend with the garden center is the area FTD florist, and sells helium balloons & cards as well as flowers as part of the deal.

He got a letter from Airgas stating that they will not be able to supply helium to non contract customers, and some other information explaning the present helium shortage.

He recieved similar notice a few years ago in a previous helium shortage.