San Diego vacuum brazing furnace zinc contamination disaster

$2M brazing furnace contaminated when wrong (Zn-bearing) braze alloy was run. Attempted recovery by raising furnace temperature to vaporize Zn out; instead redistributed Zn from hot zones to cooler water-cooled walls. Recovery attempt destroyed the furnace.

I had a situation where a guy had a two-million-dollar brazing furnace down in San Diego, and someone put the wrong braze alloy in there, ran the brazing system, and contaminated the whole system with zinc. Rather than think about how to do it, they decided they'd just try to heat the whole thing up even hotter — vaporize it out of the furnace. Except the furnace has hot spots and cooler spots. The outside is water-cooled; you can put your hand on the wall of the vacuum furnace when it's running. So all they did was move the zinc into the cooler regions. By the time they screwed up trying to fix it the quick and dirty way, they ended up destroying the whole furnace.