TIG welding copper tube...

admin

Hey guys,I have customer who is into artistic taxidermy & uses a lot of copper for his setups for added & enhancing aesthetics. He called yesterday & was in dire need of a repair that had to be done for today. He said the copper tube mount frame I sil-soldered in Jan had (2) holes from him drilling carelessly to remove some epoxy filler he added to the inside. He brought it over yesterday & showed me the damage & if it could be salvaged. The area was extremely thin from his inside grinding as the tubing was only .040 thickness to start. I told him I could make a copper plug to put inside & then add filler to close them up. The only issue would be the epoxy inside as it would probably create a lot of impurities with the copper.I took my pencil die-grinder to grind some of the epoxy to see if it could be removed easily. Nope....a pia. I then took a propane torch with light feathering flame & heated it to soften it. Wow.....the black smoke was acrid as I had to open both doors of the shop, although the epoxy plug fell out. Whew!  I took a piece of 1/2" copper tube, split it with a cutoff wheel, chucked a mandrel in the lathe & peaned a bit under the ID size. It fit good so I could add filler from the inside to the outside as the tube was so thin.I took another piece of the copper tube I had, hammered it flat, & SS wire wheeled it to a bright surface to use as a setup piece for the TIG. I didn't have any copper TIG rod, so I stripped 2' of #10 copper wire & cleaned it with Scotch pad & acetone. It was then I remembered it had been over 15 yrs since I Tigged copper.....had to refresh cobwebbed memory. Setup was easy as the filler worked well. I set it up on the weld table & started the arc on the inside plug adding filler.....just a small dab at a time to keep the tubing from melting. Took (6) passes, cleaning between passes & filled in nicely. I had a little over an hour total time. He came over this morning to pick it up & was quite pleased with the repair & no complaints with the $100 fee. Here's some pics of the project. Gonna need (2) posts, so give me a couple xtra minutes to get them on. Thanks....Denny Attached ImagesComplete Welding/Machine/Fab. ShopMobile UnitFinally retired*Moderator*"A man's word is his honor...without honor there is nothing.""Words are like bullets.... Once they leave your muzzle, you cannot get them back."
Reply:Here's the 2nd group. BTW, #10 copper wire is de-oxidized pure copper & does TIG weld nicely. His tubing was "L" grade tube.Denny Attached ImagesComplete Welding/Machine/Fab. ShopMobile UnitFinally retired*Moderator*"A man's word is his honor...without honor there is nothing.""Words are like bullets.... Once they leave your muzzle, you cannot get them back."
Reply:great repair!
Reply:Good job "Mr. Artiste".  Maybe you should be doing the art around there!  Wonder which job Weldor or Artist gets paid better?BTW, I have used copper electrical wire to tig up the contacts in a Toyota starter solenoid that I had to get running overnight.  You are right, it works just great.Miller Syncrowave 350Millermatic 252/ 30A spoolgunMiller Bobcat 225g w/ 3545 spoolgunLincoln PowerArc4000Lincoln 175 Mig  Lincoln 135 Mig Everlast 250EX TigCentury ac/dc 230 amp stickVictor O/AHypertherm 1000 plasma
Reply:You have MORE patients than me Yorkiepap........I would have beat it to death with a hammer and had a Miller...  Miller Dynasty 350Twenty Six HammersThree Crow BarsBig Rock
Reply:do the welds turn out pretty good on the inside? i heard the hardest part of copper tube welding is getting the inside to turn out right... is this true? is it like TIG welding aluminum more or stainless steel?EDIT: would you use silicon bronze or copper filler for a tig weld like this? would you do anything different if you knew water would be going through the pipe?Last edited by lozoot; 02-28-2011 at 01:55 AM.
Reply:Hey guys,B_C:  Naw.....the fellow is a good customer & really does some fantastic artistic taxidermy. He showed me a lot of pictures of his work & the design of the mountings to enhance the visual effect. He really wants to win 1st place this year.lozoot:  Like I posted, it has been quite a while since I Tigged copper, so this was kinda a refresher. Copper is soft, & like aluminum, has to be clean & you really have to pay attention to the arc controlling the heat with pedal manipulation. That's why I did a setup piece, the 1st pic, to refresh the "feel" of arc/puddle control. Copper does weld beautifully. If you look at all the pics/postings of B_C's jobs, you can see the absolute control he maintains that produces such superb aesthetics & strength. That's the goal.When doing a repair like this, the purpose of the tube will dictate if the repair is feasible. This particular project is simply a tubing assembly to support a deer head mounting. His adding a reinforcing filler inside was to keep the tubing from bending from the weight of the deer head. His issue was too much filler that impeded the deer head support rod that goes inside the tube & trying to remove some, caused his drill bit to wander & pierce the tube wall. This particular repair had to be with copper as the finish had to be the same color so as not to present a discoloration that would not have been appropriate for the judging of the customers' entry. Each flaw reduces points when grading the entry. He will be doing the external polishing & then adding a solution to effect a patina finish.If this was going to have water going thru it, the simple solution would have been to cut the tube, remove the damaged area, & add a coupler.....plumbers' do this all the time. The inside plug & filler I added was to strengthen the tube & have material to TIG to. Hope this clears it up for you.DennyComplete Welding/Machine/Fab. ShopMobile UnitFinally retired*Moderator*"A man's word is his honor...without honor there is nothing.""Words are like bullets.... Once they leave your muzzle, you cannot get them back."