Copper welding

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Hi guys, this is my first post here.I'm joining some copperplates with TIG-welding. The plates are roughly 300 mm long, and 2 mm thick. I'll put up a picture later.The welding must be grinded away to get a smooth surface. The problem is, there are holes in the welding*, which must be repaired to pass the quality control. It takes us too long time to repair, so if anyone can point me in the right direction, to get rid of the holes, it will be great * I don't know the English term for the holes. It looks like when you weld without gas.The welding looks great, and no holes to see, until we grind the welding away.Hope to get some imputs.
Reply:The holes sound like porosity. Maybe not enough gas or maybe filler? What are you usingfor fillerHTP Invertig 201Lincoln Idealarc SP250Miller 180 AC StickBy farmall:They should have held the seagull closer to the work, squeezing evenly for best deposition.
Reply:Yes, it is porosity..They are formed like a cap, we have tried both Argon and 70/30 Argon/Helium as rear-shielding gas?, and weldinggas.Argon/Helium is much warmer, and is easier to weld with. It also gives more penetration.The filler = Rod? is DIN1733 CuSn W2.1006We have tried DIN1733 CuSn6 W2.1022 - It is more "thin-liquid", but makes all worse.
Reply:try tigging it with silicon-bronze rod.
Reply:im frist to admit i dont know schittt.but that rod you are using is copper tin which sounds like solder to me....is it tiggable? or does it require flux?
Reply:A common source of porosity in TIG welding copper is the copper alloy itself.  Alloy 122 makes it look easy and Alloy 110 will give you problems all day long.  The difference is the balance (0.1%) phosphorous in the 122 that is not present in the 110.Additionally, welding with a 10° uphill can aid in the reduction of porosity formation.
Reply:Originally Posted by FegenbushAdditionally, welding with a 10° uphill can aid in the reduction of porosity formation.
Reply:Originally Posted by weldbeadim frist to admit i dont know schittt.but that rod you are using is copper tin which sounds like solder to me....is it tiggable? or does it require flux?
Reply:Originally Posted by FegenbushA common source of porosity in TIG welding copper is the copper alloy itself.  Alloy 122 makes it look easy and Alloy 110 will give you problems all day long.  The difference is the balance (0.1%) phosphorous in the 122 that is not present in the 110.Additionally, welding with a 10° uphill can aid in the reduction of porosity formation.
Reply:As Fegenbush states, I also recall reading that the type of copper, how it is produced, and/or the composition, will greatly affect the weld quality, porosity/etc.  I have not researched this subject, but I have made a few welds on common copper pipe joints which are normally soldered, just to see what it would take to make a copper TIG weld.  This a link to the original posting I did on copper TIG.http://weldingweb.com/vbb/showthread.php...ght=copper+TIGFirst, as I presume you have already pursued, ensure that the base metal is absolutely free of any contaminates/oxides/hydrocarbons/moisture, and that your shielding gas is quality is consistent and free of any leaks throughout the entire delivery plumbing, and that the shelding at the weld is adequate with regard to gas lens diameter/flow rate/etc.I am interested to learn what you determine to be the cause of your issue.Thanks.
Reply:Originally Posted by 4sfedYou have my attention.  Can you explain why welding uphill will reduce porosity?
Reply:i am no tig guru and have no experience (besides plumbing) with copper   but have read a lil on the subject because its interesting and i do remember  some used thin strips of the parent copper for filler would this be something worth a try ???350P 30A spool gun cut master 51  syncro 250 other stuff " take a dog off the street and make him prosper and he will not bite you sad the same cannot be said for man" i didnt use punctuation just to piss you off
Reply:Originally Posted by FegenbushTo be honest, I don't have a clue why it works.  I can only presume that the angle allows the "slag" (oxides from the flux and various sundry crap) to flow away from the weld pool as opposed to falling in front of it to get trapped, causing porosity.
Reply:Originally Posted by pulserAs Fegenbush states, I also recall reading that the type of copper, how it is produced, and/or the composition, will greatly affect the weld quality, porosity/etc.  I have not researched this subject, but I have made a few welds on common copper pipe joints which are normally soldered, just to see what it would take to make a copper TIG weld.  This a link to the original posting I did on copper TIG.http://weldingweb.com/vbb/showthread.php...ght=copper+TIGFirst, as I presume you have already pursued, ensure that the base metal is absolutely free of any contaminates/oxides/hydrocarbons/moisture, and that your shielding gas is quality is consistent and free of any leaks throughout the entire delivery plumbing, and that the shelding at the weld is adequate with regard to gas lens diameter/flow rate/etc.I am interested to learn what you determine to be the cause of your issue.Thanks.
Reply:Good catch on the back cap o-ring.  Many people don"t realize that a leak or a pressurized system can allow air to enter.
Reply:glad you got it fixed post some more pics of the copper work if ya get a chance love that stuff 350P 30A spool gun cut master 51  syncro 250 other stuff " take a dog off the street and make him prosper and he will not bite you sad the same cannot be said for man" i didnt use punctuation just to piss you off
Reply:I use a copper tig rod that I get from my LWS.......DC - with a good grade of helium...  Miller Dynasty 350Twenty Six HammersThree Crow BarsBig Rock
Reply:Originally Posted by pulserGood catch on the back cap o-ring.  Many people don"t realize that a leak or a pressurized system can allow air to enter.
Reply:Looks really good, B_C