[TheForge] Dont put your tongue on a frozen anvil round 2

[Mike Spencer]

> Not enough information.  Depends upon the anvil, depends upon how
> hard you hit it, depends upon where you hit it, depends on how cold
> it is.

Another thought:  Catastrophic crack failures begin at micro-cracks, [1]
whether or not the margin of safety has been reduced greatly by a
combination of hydrogen/sulfur/whatever embrittlement and low temps.
So if you're obliged to use a very cold anvil and are worried, it
might be helpful to have your anvil shotpeened.  This tends to close up
micro-cracks and put a shallow layer of the surface in compression --
sort of pre-stressing in the direction opposite to the tension that
encourages crack propagation.

I don't know just what kind of finish that would leave on the working
face but it would be worth a try.  The only place I've actually seen
this in use was for 6' long aluminum propeller blades but I'm sure
it's a widespread technology.


[1]  I'm not so sure about compression spalling but I think that's more
     complicated and unlikely to happen to anvils used for hand
     hammering.

- Mike

-- 
Michael Spencer                  Nova Scotia, Canada       .~. 
                                                           /V\ 
mspencer at tallships.ca                                     /( )\
http://home.tallships.ca/mspencer/                        ^^-^^

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