I've been lurking here for a while and just signed up to throw my 2 cents in recently. So now that I'm here (and to head off any ideas that I don't learn something new every day), I have a question for some of the more experienced welders.
I'm sure that almost all of us have encountered broken die-castings. Not unusual since some have a ductile-brittle transition temperature not far below room temp. Has anyone got any tips/tricks for welding die-castings of high zinc content alloys like Zamac (ZAMAK)? I tried once some time ago... TIG welding/argon/various tungstens/polarities/etc and all I got was a crappy weld because it would pop and spit out metal before I could even develop a real puddle.
I assume it was the zinc vaporizing before the other stuff (Al/Mg/Cu) was even halfway to their melting point. Being unable to weld inside of an atmosphere of 20 tons per square inch to keep the zinc from volatizing, I gave up. But I revisited this question last week when someone brought a GM tilt steering column to me that cracked when the 4 bolts deep inside backed out and let the wheel thump back and forth.
I know this stuff used to get soldered with a special Cadmium alloy solder (EXTREMELY dangerous/toxic) but that's out of the question. Anyone recommend different gas, particular tungsten, AC squarewave, AC sinusoidal, particular balance, glovebox atmospere?
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Thread: Welding Die-Cast Zinc Alloys?
02-28-2008, 02:15 AM #1
Welding Die-Cast Zinc Alloys?
02-28-2008, 10:35 AM #2Member
- Join Date
- Nov 2007
- Jackson, MI
I've always been told it can't be done.
02-28-2008, 05:43 PM #3
http://www.crownalloys.com makes a torch repair rod for zinc aka potmetal. I have some and its Royal Kirkrod and it works pretty good. You see those guys at the flea markets/swap meets repairing junk and selling their brand of rod and they do a good job of fixing non critical parts. Royal Kirkrod 18" & 36" For Torch or Tig to Repair Zinc Based Metals..Bob
Last edited by aametalmaster; 02-28-2008 at 05:45 PM.Bob Wright, Grandson of Tee Nee Boat Trailer Founder
Metal Master Fab Salem, Oh 44460
Birthplace of the Silver & Deming Drill
1999 MM185 w/185 Spoolgun,1986 Thunderbolt AC/DC
02-28-2008, 06:10 PM #4
Die Cast Welding
It was commonly done years ago. I myself have welded up a few of the older carb castings.I have a page scanned from one of my old welding books, but I cant get the file size small enough to post. If anyone wants it PM me with your address. In short you can use the aladdin filler rods with a OA torch, about a 3x carburizing flame and working the oxides out as you go. It can also be soldered usually with aluminum solders such as the ones sold by Brazing Technologies Group.
-Aaron"Better Metalworking Through Research"
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