Size Welder To Tig 3/16" Copper ???

admin

Please help on this guys!  What amp TIG welder I need to join 3/16" copper sheet? Any Lincoln or Miller model in mind?
Reply:I think you're not getting any responses to your question because this is a very unusual and difficult task that no one here has experience with.  Copper is tough to weld because the heat conducts to radically fast, and the thicker it is the tougher.First, I suggest you reconsider full up welding.  Do you have long joints that need to be fully welded?  Can you just apply short weld segments in a few strategic places?  Do you have to fully grind and smooth the welded joints?  Could the joints be brazed, either TIG or Torch?  Or soldered?  How about some artfully placed stainless steel bolts for the main strength you need?If you can configure the weld joints to be tight fitting outside corner joints, it may not be too difficult to fusion weld, without adding filler, and consistently get about 1/2 thickness penetration.  If I had this situation, with really consistent fitup corner joints, I would think about a 300 to 500 amp pulsed TIG power supply and radical pulse parameters to produce a really pretty "stack of dimes" type weld that would be part of the beauty of the sculpture.  Different joint, but something like this:  http://www.weldingweb.com/vbb/showthread...ght=copper+tigBut if you need full penetration, or have a square butt, this will be much more difficult.  And if there are fillet or groove joints that require added filler, very difficult as well.  Plus, not sure where you buy copper filler, you may have to shear diller "rods" from your base metal.Now, TIG brazing with Everdur (silicon bronze), should not be as difficult as actual welding, since the base metal does not need to be melted.  But you may need to consider a color difference between the copper and the Everdur joint.So, whadda u think?
Reply:I agree with pulser that brazing is easier and may be a better choice, but if you need to weld (my experience with copper is up to about 3/32" or 1/8", other than things like tacking contacts and making up copper gasket rings):Any DC source with sufficient current capability will do the job. If have done copper with a Maxstar, a Synchrowave, a Lincoln SAE150, and a few others. A good remote current control is real nice. DCEN (straight polarity). Straight Argon is suitable, but many people prefer to use a helium blend, as it is  hotter. For an unbevelled butt joint, you will need 200 to 300A to run from one side, and 150 to 200A to go from both with complete fusion, depending on joint details. (http://www.aws.org/educators/Library/0000/000062.ppt slide 5)If you can bevel and can run several passes, you should be fine with a machine in the 150A category, especially if you can weld from both sides. (same PPT, slide 6--left is single Vee, right is double Vee, weldable from both sides)The Vee groove welds are easier to do manually, as the added filler helps control the puddle. For filler, you can contact your weld supplier (they should be able to get it) or you can buy deoxidized copper rod from McMaster-Carr, MSC, etc., which is usable for pure copper. If the copper is an alloy, then you may need to use cuts from your material as filler or get a specialty filler from a supplier.There are a few people here that do exotics regularly, and I'm sure that some of them will give more thorough advice.
Reply:http://www.weldingweb.com/vbb/showthread...ght=copper+tigThose are some nice welds Pulsar.
Reply:I have tig welded a fair amount of copper. Its actually pretty easy- but it really sucks up the amps.I did a piece a while ago that was mostly 1/8" plate and schedule 40 pipe- and it took every amp my syncrowave 250 had- and, turned up all the way, thats around 300 amps.I dont think multiple passes with a little machine is gonna cut it- it just sucks the heat away too fast.And when you put all that amperage into the metal, it gets very hot.Copper conducts heat really well- so we had to step weld, and then let it cool for quite a while in between steps, as the copper got so hot that even with the really thick aluminized gloves, it was radiating so much heat you couldnt get within six inches of it to hold a filler rod.The welding itself turned out really nice though, easy to do and it looked great.
Reply:Mass amounts of preheat. Just like welding thick [1"] aluminum with my Dynasty200 DX. With the correct preheat a small amp machine can do a lot. Jimmy
Reply:Originally Posted by worldsgreatestwelderMass amounts of preheat. Just like welding thick [1"] aluminum with my Dynasty200 DX. With the correct preheat a small amp machine can do a lot. Jimmy
Reply:Another issue could be if it is deoxidized copper or not. Could make a difference in the weld.  Also your gas proportions could affect it too.
Reply:One more note on welding copper.  When you heat it that hot it will get (and stay) very soft, so depending on what it is being used for welding may not always be a good thing.Me!
Reply:hi Pulser: Let`s say I go down to 1/8" copper sheet instead of 3/16", and need to do long but and mostly overlap welds. Do I go TIG or Mig? To me that is a key question I`d better get an answer before I go nuts on this. I gotta give an estimate for the work so I`m concern about MIG wire cost. Have any idea the consumption rate: lbs Cu wire/hr to weld 1/8" sheet? The bronze color I`d like to avoid, so do you think I could use copper filler rod with TIG? Some people have told that MIG is a big mess. is it that messy ? In regards to messy equipment I`ve been told hand plasma cutters suck. Is that so, and what could I use to cut sheet and make ends meet? is disk cutting my best choice? As you see, all I got is questions in my mind, and a lot of confusion. I there is Cu wire to MIG weld, I believe this might be a good shot to maintain Cu color. This an sculpture project and asthetics is very important. Well buddy, needless to say how greatful I am for your just taking the time to help me . baculus.
Reply:hi Pulser: Let`s say I go down to 1/8" copper sheet instead of 3/16", and need to do long but and mostly overlap welds. Do I go TIG or Mig? To me that is a key question I`d better get an answer before I go nuts on this. I gotta give an estimate for the work so I`m concern about MIG wire cost. Have any idea the consumption rate: lbs Cu wire/hr to weld 1/8" sheet? The bronze color I`d like to avoid, so do you think I could use copper filler rod with TIG? Some people have told that MIG is a big mess. is it that messy ? In regards to messy equipment I`ve been told hand plasma cutters suck. Is that so, and what could I use to cut sheet and make ends meet? is disk cutting my best choice? As you see, all I got is questions in my mind, and a lot of confusion. I there is Cu wire to MIG weld, I believe this might be a good shot to maintain Cu color. This an sculpture project and asthetics is very important. Well buddy, needless to say how greatful I am for your just taking the time to help me . baculus.
Reply:Excuses, it took me so long to answer. I`ve had problems loggin in, and when I did, then I double post a reply. great huh! Enlpck,thanks for tips.  One more question: I want to buy a LINCOLN TIG welder that will weld 1/8" with ease. What model or amp machine you recomend? And any experience with a hand plasma metal cutter? I wonder if it`d be okay to cut copper sheet. Baculus
Reply:Ries you`ve done a lot of TIG, how many pounds of filler rod /hr, foot  to weld 1/8 " sheet , just a guess!  Thank you much for advice. I`m starting to see the light at the end of the tunnel ! baculus
Reply:A plasma will cut just about anything you want to stick under it, but the copper will probably be about like aluminum. Most plasma cutters will only handle half the thickness in AL that they will in steel. Meaning 1/4" steel equals 1/8"aluminum. You do realize they make silver solders that match copper, and that might be a better, faster, and much more cost effective solution for you. Try Rio Grande in Albuquerque, NM. http://www.riogrande.com/Without knowing any specifics about your sculpture it is hard to say. Some copper alloys don't weld well, others not at all by any process. You can find that info out at Lincoln Electrics website. Any weld you make on the copper will be dead soft as those temps are far beyond those needed for annealing. That needs to be taken into account in any joint design. Is this small scale, large scale, freestanding, armatured, wallhanging, etc? It sounds as though you may be in way over your head.The difference between art and craft is the quality of the workmanship. I am an artist.
Reply:baculus--as you have repeatedly indicated and other posters have stated--There's a whole slew of variables, choices, methods, materials, material conditions (annealed, half hard, oxidized, de-oxidized) involved in this project. This is not a cut & dried, been dun 10,000 times before, kinda deal.This project consists of 3 major phases: 1-Design and prototype as needed 2-Quote the design, from experience gained on the prototype 3-Fabricate the designSince this is a one off, one time only--artistic sculpture--somebody, somewhere is going to be doing proto work.  The aesthetic aspect alone--dictates doing proto work, plus all the other variables.You can start by breaking the main design parts into the areas of question, etc., then determining (and guessing!) just what kind of items you'll need to proto.It's up to you to aprise the client-- that the design/development/prototyping will cost and is required--for anybody to quote this job--fairly and intelligently, for the benefit of all parties concerned.      Prototyping before the quote, is the prudent way to avoid big problem$ on the other end.                                      'R & D--ain't 4 free!'Blackbird
Reply:I am an artist myself, but I pay the bills welding. Having been in the community for awhile as well as getting my bachelors in art (long after I was a pro class welder) you need to understand that most artists getting involved in metal sculpture really don't have a good understanding of the materials and processes involved. I have seen them take 6 months to complete work that would take me two weeks from concept to completion. Many are in way over their heads and don't understand that sometimes some things should be turned over to a pro. One of the metal sculptors in a group I belonged to before coming to LA was killed a few months back because the sculpture he was working on fell on him. He forgot about balance, and didn't have it supported. I have to admit I sometimes get ideas that require tremendous amounts of research just to reach the point of being able to consider beginning. Without the many years in fabrication they would be almost impossible for me to complete. With that said I also feel an artist shouldn't undertake a commission that he doesn't already have the proven skills to accomplish. I know several who use metal components in their work who never do any of the actual fab and welding work. When asked why most say because I don't know what I am doing. A couple of the guys are incredibly successful. All you are going to get here baculus is advice and options, not the skill needed to complete the project.The difference between art and craft is the quality of the workmanship. I am an artist.
Reply:First- mig versus tig- Tig is going to be a better choice for a sculpture- its more controllable, gives a better looking weld that will require less cleanup.Also, although you can buy deoxidised copper wire for mig, its really expensive, and you have to buy an entire roll- whereas, with tig, you buy rod by the pound, as you need it.I have never migged copper- but my guess is that it, too, would require a big machine to do right.I cant tell you consumption or hourly rate of welding- me, I build a lot of sculpture as well, and we just dont worry about how many pounds per hour of weld- instead, we worry about getting it absolutely right- and that takes a lot more time, and fussing, than if we were building some industrial product, where the way it looks is not as important as how much it costs.So its very hard to bid based on pounds or hours- bidding to build a sculpture is a very hard target, and the only people I know who are somewhat accurate in their bids have been doing it for 20 years or more. Figure it will take longer, and cost more. Thats always true.As for plasma- I have found its not very good for copper or bronze alloys. It will work, but it is messy. My advice, before buying a plasma, is to take a sample of the actual alloy you want to cut down to the local welding supply store, and try it out. Of course, you cant do that online. Which is why buying machines from welding supply stores is still a good idea. Copper cuts easily with saws, shears, and can be waterjet cut quite nicely as well. Not sure what you mean by "disc cutting" but if you are talking about using a 4 1/2" grinder with a cut disc- well, that would be my last choice. For copper sheet, in 1/8", I use a Bosch jigsaw, plasma, a bandsaw, and my ironworker to cut it.  As for buying a tig- if it must be Lincoln, I would be looking at a precision tig 275, or maybe an invertec 205- I would not want to do a job like you describe with anything smaller. I would definitely want a water cooled torch, foot pedal, and high freq start. You will weld this DC, but most of the machines that will make this an easier job are AC/DC, and its certainly nicer down the road to have an AC/DC  welder. However, if you KNOW you will never need AC to weld aluminum, a nice DC inverter would do a great job on this- we do stuff like this with my Miller 304XMT, with a high freq unit and radiator hooked up- not a cheap setup, but killer for high amperage DC tig welding.Making stuff out of expensive alloys is always a lot pricier than working with mild steel. Bid high.
Reply:Hello,I weld copper parts (brush holders)for large motors (1000 Hp and bigger).  Most of the stuff is rolled 1.5" wide X 1/4" or 1/2" thick (bar rolled to a radius).  The joints are vertical up or flat.Aside from the preheat (you must preheat until the joint is cherry red), I run anywhere from 200 amps (DC straight polity) to about 300 amps.  The difficulty arrises when too much heat builds up in the joint, and everything falls away.  The best techniques I have used require using magnifying lenses (I use 2.75 to a 4.0 diopter), as you really need to read the puddle.  The other thing is that using a "hot pickle" - to clean the joints is beneficial.  (It can also behave like a flux - if you can handle the "bright orange flames" when re-heating a cluster to get to subsequent joints.  The real difficulty is in getting the joint pre-heated (hot enough) and quickly getting on it with the tig torch.  It can be quite a challange.  (I've got probably 7,000 hrs. or more behind a torch, and I'm not pulling your leg).  Also, I use a Helium-Argon mix (25-75), but feel that straight argon would be just as good at these preheat levels.  The other challange is that since copper is not alloyed, it all melts at one temperature, so you really don't have any liquation (mushy stage in alloys).  Good luck, and practice, followed up with "destructive testing" to verify that you're not just making pretty welds which lack the proper mixing of base metal with weld rod.Pat
Reply:Hello,I weld copper parts (brush holders)for large motors (1000 Hp and bigger).  Most of the stuff is rolled 1.5" wide X 1/4" or 1/2" thick (bar rolled to a radius).  The joints are vertical up or flat.Aside from the preheat (you must preheat until the joint is cherry red), I run anywhere from 200 amps (DC straight polity) to about 300 amps.  The difficulty arrises when too much heat builds up in the joint, and everything falls away.  The best techniques I have used require using magnifying lenses (I use 2.75 to a 4.0 diopter), as you really need to read the puddle.  The other thing is that using a "hot pickle" - to clean the joints is beneficial).  (It can also behave like a flux - if you can handle the "bright orange flames" when re-heating a cluster to get to subsequent joints.  The real difficulty is in getting the joint pre-heated (hot enough) and quickly getting on it with the tig torch.  It can be quite a challange.  (I've got probably 7,000 hrs. or more behind a torch, and I'm not pulling your leg).  Also, I use a Helium-Argon mix (25-75), but feel that straight argon would be just as good at these preheat levels.  The other challange is that since copper is not alloyed, it all melts at one temperature, so you really don't have any liquation (mushy stage in alloys).  Good luck, and practice, followed up with "destructive testing" to verify that you're not just making pretty welds which lack the proper mixing of base metal with weld rod.Pat
Reply:That is why I asked all the questions regarding what type sculpture it is because depending on the type there might be a better option than welding or even solid copper for that matter. I am really concerned with skill level because asking what type and size machine is needed is a dead giveaway of inexperience. If it's a large scale freestanding sculpture and it falls or self destructs and someone is hurt or killed then a career just went down the sewer pipes. Industrial components all get top quality welding at this shop. That could be why the competition is disappearing while I am getting further behind (currently 6 months). Artwork on the other hand is a different story depending on the appearance desired. On one project it was specifically requested that the cutting be rough, out of square, crooked lines as opposed to straight and that it be beat up and rusty. As the customer put it he wanted it to appear that someone did it in their back yard. Salt water and a jackhammer took care of the rusty and beat up. The cutting was a bit more difficult as I am used to doing everything smooth and square. When I am going for a rustic look I don't necessarily want nice smooth pretty beads. That doesn't mean it isn't first class welding, it just appears otherwise.The difference between art and craft is the quality of the workmanship. I am an artist.
Reply:Hi Jolly: I`m an sculptor and do iron,wood,and cement work,and will attempt any artistic work once I`m sure about tecnical details I truly ignore now.If you had your shop here in venezuela where the work will be done,there`s no doubt in my mind you might be doing the sculpture and not me,or we may be doing it together,probably.The multiple question matter is what welding process`d be the more efficient to acomplish the structural strength,and the asthetics of the sculpture.The structure design is taken care of,but eventhough the client has 3/16" Cu sheet,the massive amounts of heat required to TIG weld,as the weight of the sculpture would be massive and increase costs,risks,etc.,I`m telling him let`s get 1/8 sheet! Although I can stick weld well(artistically) and O/A brace, I considered other processes,and that`s what brings me to this forum.You`re quite right about the inexperience give away,but believe me that I have learned so much in the last two weeks chatting with guys like you who really know well their particular abilities in one process or another.I will not attempt building a skyscraper for a start,but a one to three story house I will build it.It may take me a little longer... but that ain`t a problem if the house turns out structurally sound, beautifull,and I can pay bills. I`ve done some heavy projects,and usually I tend to over estimate materials for safety purposes.Nevertheless,it must be understood the relationships between total weight,strength of materials,foundation,balance of high structures, and the asthetics in the case of a sculpture.On the other hand,there are parts in the sculpture I don`t wish to overestimate at all, for they may increase the costs to much.You sure understand the point. Now Jolly,I`ve talk the client into getting 1/8 Cu sheet so to make things easier. So I believe a 300 amp TIG welder would suffice.Nevertheless, I just talked to an artist that O/A welded a beutifull tree using O Phos copper rod (I`m not sure if I`m getting the name right).The reason being that we don`t want the yellow color of bronce bracing. Someone else mentioned soldering with copper color silver, but I`m concerned about the strength of such alloy and how it would weather compared to the copper sheet soldered to.The tree will be about 20 ft tall and the Cu sheet will be heat forged over the shaped structure. I do have good experience forging,just want a fairly strong weld/brace that looks like or close to copper.Dat`s it! That`s the detail I need to get down before I run to buy a TIG welder. Another thing Jolly, I went to college in the U.S.,more precisely in Davis and in Sacramento, California.Worked in the state for two years,there are big diferences between places.So I tell you  and believe me that artists here do not readily have access to tecnology, so I have to find economical options. For an artist here to have plasma cutter,a power hammer, TIG, MIG, and so many other gadgets readily available in other countries, is not easy! There are heavy industries  that can afford any tecnology they required,but we`re talking from and artist and artisian level.Gadgets are very expensive here,and sometimes you don`t even find them. Let me tell you though that the only cheap thing here is gasoline: about  US 5cents/gal  LOL ! Jolly, I truly appreciate your having taking the time for providing input, and you surely understand the situation better. What would be your advice on this darn copper sheet welding issue? Thanks so much to you and all again. baculus