whats this material?

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a customer got this old bar top and wants me to do things to it.I dont know what it is.He calls it zinc.think it was made in france (so he says)somehow i feel that there is a lot of magnesium in it.any suggestions? Attached ImagesG
Reply:Find a hidden area where a small piece can be cut off and then test that to determine its composition.  If pure zinc, it will quickly dissolve in HCL and give off hydrogen, then the resulting solution can be further tested if needed. Also, if zinc, the melting point  can be determined by someone with the proper means. The melting range is a good indication of purity.Any chance it's nickle-plated copper or brass? Should be obvious if stainless, which, if it's very old, is unlikely.
Reply:HCl (hydrochloric acid) will dissolve  a lot of metals.  Zinc and magnesium included.Just what does the customer want you to do to that and just how 'critical' is knowing the composition of the metal to said bar top?  If 'critical' or even you just don't know or can't seem to figure out what the metal/alloy is, then have it 'tested'.  http://www.spectro.com/pages/e/p0105.htm  The best laid schemes ... Gang oft agley ...
Reply:gordfraser  -  From its look and origin I think it's Nickel Silver, an alloy of copper, nickel and zinc.  Search the Web for particulars.    Opus
Reply:thanks members.especially opus. Nckel silver,  that looks very likely i was asked to cut some of the top off and fill in some holes. Holes that pipes went through. (ie not pin holes)  some of the repairs wil be seen so it needs to match up well.G
Reply:I am going to cut off a lot of the lower parts on the inside.should be able to use that parts to make filler rods.assuming it is nickel silver what tig process? AC or DC?argon should be fine i hope?im going to cut some of it off soon, so i can try out settings on the off cuts, but it would be nice to be informed before hand.Last edited by gordfraser; 05-25-2012 at 10:42 PM.G
Reply:Start by putting a magnet to it. then it could rule out a few metals.
Reply:gordfraser  -  If in deed this is Nickel /Silver, explain to your clientthat this is a 'lost-metal' artifact, and you should do nothing to jeopardized it current integrity and value.  Consider blind flanging [fixturing] the holes with S/S instead of attempting to plug weld them.  Anyone who has tried to plug holes in sheet metal knows the results are tenuous.  This may be a welding instance that the 'do nothing' option is the higher value.        Opus
Reply:Originally Posted by MoonRise... If 'critical' or even you just don't know or can't seem to figure out what the metal/alloy is, then have it 'tested'.  http://www.spectro.com/pages/e/p0105.htm
Reply:If it is Nickel Silver, I would silver solder it with O/A rather than TIG. Nickel Silver contains a fair amount of Zinc, which messes with the TIG arc.If you are cutting large parts of it away, you can make some discs that just fit inside the holes,and Silver solder them.Since this is for a bar, make sure to use an NSF-approved Silver solder (no Cadmium).OTOH, as Opus Ferro implied, welding thin sheet can be "problematic". There was a thread in the Projects section recently regarding welding on stainless counter-tops and why this should be avoided when possible. JohnA few weldersA lot of hammersA whole lot of C-clamps
Reply:Originally Posted by Silicon-basedIf it is Nickel Silver, I would silver solder it with O/A rather than TIG. Nickel Silver contains a fair amount of Zinc, which messes with the TIG arc.If you are cutting large parts of it away, you can make some discs that just fit inside the holes,and Silver solder them.Since this is for a bar, make sure to use an NSF-approved Silver solder (no Cadmium).OTOH, as Opus Ferro implied, welding thin sheet can be "problematic". There was a thread in the Projects section recently regarding welding on stainless counter-tops and why this should be avoided when possible. John
Reply:Thanks guy'sI am going to try tigging on a hidden area, with an offcut as a filler.see what happens.the customer will not be concerned about loosing any value of the top. he is very rich and determined.ill let you all know what evolvesG
Reply:update.tried to tig it.melted way before i thought it would. I can weld beer cans together at 20 to 30 amps.this puddle fell out at 9 to 15 amps.not that i saw the puddle. as i started and leaned on the pedal. once the arc stabalised, i stepped a little more.  then the arc went wild, running arount all over the place. So i stopped.there was nothing there. dime sized area had gone. I hadnt even seen a puddle!the pics show an area that was a rip before.pics are bad phone pics.i can get moreafter thinking a little.can this thing be made from solder?even cast with solder?its the closest thing that i can associate it with.the work wasnt even warm 2 mins after the experiment!intriguedG
Reply:and some pics Attached ImagesG
Reply:If, as I suspect, the material has a high percentage of zinc, the zinc is vaporizing from the heat of the tig arc.With a melting point of less than 800 deg F, the zinc is going to give problems even with silver solder.The only time I've encountered similar material was in a bank we were restoring in Petersburg, VA back in the early 60's.  The bank had been built well before the civil war.  The material had been "hammered" to a pattern and was used in the ceiling and as a crown moulding.Think I'd be googling "tin smiths" if it were me looking at this job.Syncro 250 DX Dynasty 200 DXMM 251 w/30A SG XMT 304 w/714 Feeder & Optima PulserHH187Dialarc 250 AC/DCHypertherm PM 1250Smith, Harris, Victor O/ASmith and Thermco Gas MixersAccess to a full fab shop with CNC Plasma, Water Jet, etc.
Reply:Break out the JB Weld!
Reply:How 'stiff' is it, meaning how easily is it bent? Does it make any sound if you put one side of a piece in a vise and, using a ViseGrip, quickly bend it 90*?Take a small piece, set it on a fire brick or something similar and heat it slowly with a propane (or a small OA ) torch. How does it behave? Does it quickly ball up and/or does it start 'smoking' if you continue heating? How does the resulting bead act if you hit it with a small hammer?You might try alloying a small bead with a similar sized bit of lead-tin solder.I haven't heard any of the other responders (who suggested the handheld tester) offer to do any tests for you yet!
Reply:as stated it is most likely ZINC they do make counter tops out of it, Videos on how to do zinc counter tops,  http://www.rotometals.com/Zinc-Sheet-Videos-s/55.htmflux and solder and so on as well as zinc sheets http://www.rotometals.com/ZINC-SHEETS-s/29.htmI have not bought Zinc sheets from the company but have bought some things from them in the past and had no problmes.Last edited by Farmerboy; 05-29-2012 at 11:19 PM.
Reply:gordfraser  -  When you select a gun, you have to know what you are hunting.  Identify the material first, other wise you are wasting your time.  Striking an arc is not material testing.  Given that, if you had searched the web, "for the particulars" you would have discovered that TIG was not appropriate for any zinc alloy.  Compare your sample with TIG/ed brass, center section, not on the edge.  Note the porosity, zinc vaporization, out of the copper, in both samples.  Reduce your temperature by going to a torch, and research for appropriate solders/fillers; if none, fixture a blind face.    Opus