pot metal ?? welding???

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Anyone here have any experence welding pot metal? I have a part that i thought was allum. but to my suprise it wasn't when I tried to TIG weld it. The material seems to puddle up with the TIG, but... then it seems to flow away more so than allum. and not fuse.Material seems to be a little heavier than allum. maybe lead some content?? The part is a feed dog on a line boring machine. Any help would be appreiciated!! THANKS
Reply:The actual name of the numerous types of 'pot metal' referred to as such escapes me right now,but this site  http://www.muggyweld.com/potmetal.html  might help.There are all sorts of sites listed under pot metal repair/welding,but whichever way you go it's not going to be easy. That stuff melts like candle wax.. as you no doubt found out. (lot of zinc/aluminum in all forms of it,but it's made like a sweep the kitchen mixture of metals)Can't offer much more than that....Anyone remember the correct name for the slang term 'pot metal' ? It's been years since I even thought about that stuff....starts with a 'Z' I think.Last edited by mudbugone; 03-07-2009 at 11:03 PM.
Reply:One of the alloys, or groups of alloys, is called Zamak. The zinc-based alloys are hard to work with and it may be easier to stick the part together with adhesive and use it as a model for getting a new one cast. Or machine one from bronze on a computer-run system which can optically scan the part in 3-D.
Reply:That's It--  I was pretty sure it started with a "Z"   Thank You...that would have driven me nuts for days..
Reply:Thanks for the quick replies Is  their some way to identify what type of metal it is???    Thanks, quinq
Reply:You can determine the density by figuring out how much water it displaces and also weighing it but that will only give you an idea of what group it's in. There is no way except with fancy lab equipment to determine which alloy within a group it is; they vary both in what metals are blended and in the amounts of each used.Some zinc alloys which were used  to make parts like magnetos in the 1920's and 1930's were 'unstable'  and over time as they recrystallized, the parts would grow. It might also have due, at least partly, to reaction with water or CO2 from the air, but in any case the parts eventually disintegrated.I assume that trying to weld or braze zinc alloys could cause a similar problem someday if the wrong filler metal were used. Since it might take years, or happen in just a short time. Seems to me not to be something to guess about for important parts or  repairs.
Reply:good luck with that crap! seems to be the toughest thing ive ever tried to weld. 0% success.only thing worse than an ugly woman is an ugly weld
Reply:Cronatron Welding Systems markets a product called Cronabraze 53.  Must be used with Cronasolv 53 flux.  Flux is temperature indicating.  Looks like honey, when heat is applied turns to white powder, then when it turns to wet it's ready to accept the rod, O/A.  Made for "white metal", and VERY expensive.  I am not affiliated with Cronatron, was a saleman with them back in the 80's."Pot Metal" is something I won't repair, unless it's a do-dad.  Once repaired, it easily breaks again.  Ain't worth the time or money.
Reply:one of my students broke his factory truck step support (nissan i believe) when he and his friend both stepped on it together (by accident). it was also some crazy aluminum based pot metal, very porous stuff. we tried everything we had at school on this mess but nothing even came close. long story short, he read up on this do it all filler rods that i wasn't sure about. well, he bought it off ebay, but it was still expensive and brought it to school. we beveled the edged just a little and fired up the oxy-fuel torch and low and behold, this stuff brazed it right up. easiest, smoothest flowing stuff i ever saw, and grinds just as easy. he finished it out, put it on and it held! he's still at school in machine shop and this was done a year ago and still holding, no problems.the stuff was Alumaloy, you can still get it on ebay, still pricey for filler rods, but it worked on this project. might work on yours.johnjohnwelding instructorwww.williamrmoore.orgMooreTech College of Technologywelder/fabricatorJGWilson, Inc.www.jgwilson.com
Reply:hmmm im gonna have to get some of this stuff. never heard of it. a guy i work with said you could braze it but i thought he was fos!only thing worse than an ugly woman is an ugly weld
Reply:Posted by john.mooretechit was also some crazy aluminum based pot metal, very porous stuff.
Reply:el lloydeo, until i had seen it and tried i also thought it was fos! but that stuff worked perfectly for his step but that's all i have personally used it for. if i remember i think they say it can used for all kinds of cast material. unreal how easily it flowed!oldiron2 - we tried to find out what his step support was made from, we found it listed as cast aluminum, but bottom line, nobody knew what all was mixed in it. it was very light and very porous, thru off bright silver sparks as i recall. i had thought i'd seen alot of crazy metals in my time but this was a new one on me. wish i had taken pics to show just how porous this support was. but you're right, not technically pot metal. bad habit of lumping all these wild cast mixes in the ol pot metal catagory.johnjohnwelding instructorwww.williamrmoore.orgMooreTech College of Technologywelder/fabricatorJGWilson, Inc.www.jgwilson.com
Reply:Zamak, run into it alot with lock hardware, I think alot of it may be replaced with Delrin now.A possiblity could be if you absolutely cannot find a peice perhaps sand cast a new one.Sorry.
Reply:Well Thanks for the responses, I've got it repaired. Found it to be zinc alum. I used UTP  U-Al filler rod  with TIG, seemed to do  fairly well, even built up wore down area with it.Welco 52 was also recomended for zinc alum. but not avail. in my area. Time will tell...  THANKS again, quinq
Reply:Is there a number for that UTP alloy?  I found a list of its products but didn't see that designation in it.The Welco  52 has 3.5 to 4% Aluminum and a few percent Copper, the rest being Zinc.Here is the site:http://www.btwusa.com/english/570_ENG_HTML.htm