View Single Post
  #21  
Old 11-22-2018, 11:13 AM
crystallographic crystallographic is offline
MetalShaper of the Month October '14 , April '16, July 2020, Jan 2023
 
Join Date: Dec 2010
Location: Western Sierra Nevadas, Badger Hill, CA
Posts: 4,388
Default

Fine-tuning bits of Will's fine commentary on the Metal Camp:


Annealing temp of 5052 and 6061 is 650F - fine for black marker.
3003 is 750F and that 100F higher makes for harder results, when only annealing the 3003 using the black marker, and getting a "partial" anneal instead of a "full anneal."
(Personally, I use the color of the flame "ricochet" or bounce as my temp indication.)
By the way, 5052 is very hot sensitive, and the dark gray spots that result from over-heating usually always show signs of fatigue, before cracking during subsequent working.

Nomenclature has always been a source of confusion. After WW2 thousands of war-workers returned to "normal" jobs, taking with them rudimentary understanding of terms and procedures in other industries. This did not help established accepted terminology, and in fact brought about change/confusion that older craftsmen had issues with. However the numbers of returning workers far outnumbered the skilled oldtimers and the odd lingo persisted, even today.
One example: "hammer welding" - a misnomer used when a blacksmith is "forge welding" two pieces of metal together.

Further aberrations apply when a craftsman is "hot planishing" a gas weld on steel sheet - and that is now "hammer welding???" However, when that same hot planishing is done one inch away from the gas welded seam the term is not used. Misuse of terms makes for such awful confusion when trying to communicate what is going on.

2nd example (of many) "Silver soldering" and silver brazing" and "hard soldering" and "soft soldering" - American terms being mixed with UK terms. Silver-bearing solder with 2-3.5% silver melts at 435F, below the 850F cutoff for American solders. "Silver solder" in the UK is divided between "soft" - below 850F and "hard" - above 850F and is therefore a "brazing alloy" by American standards, above 850F.

I gave a student a Robert Mondavi uncorking tool when he asked for a "corking" tool during a recent workshop ...



Working this terminology out may help, and writing it down and getting it out in public may also help - but stuff just persists, and it takes younger generations being taught to displace the older folks holding on ... sigh, and that is just the way it is.


- end -
__________________
Kent

http://www.tinmantech.com

"All it takes is a little practical experience to blow the he!! out of a perfectly good theory." --- Lloyd Rosenquist, charter member AWS, 1919.

Last edited by crystallographic; 11-22-2018 at 01:55 PM.
Reply With Quote