[Shop-talk] Fwd: Annealing Copper bars

[Donald H Locker]

[Oops; failed to copy shop-talk.]

-------- Forwarded Message --------
Subject: Re: [Shop-talk] Annealing Copper bars
Date: Sat, 8 Aug 2020 10:57:35 -0400
From: Donald H Locker <dhlocker at comcast.net>
To: Bob Spidell <bspidell at comcast.net>

Hardening steel requires quenching to freeze in the carbide crystal
structure. Annealing steel requires slow cooling.

Copper (and Aluminum and others, but I don't have a list handy) will
annealed by heating and can be cooled quickly or slowly. They harden
with strain (bending or hammering or whatever.)

Donald.
--
*Plain Text* email -- it's an accessibility issue
() no proprietary attachments; no html mail
/\ <https://www.georgedillon.com/web/html_email_is_evil.shtml>

On 2020-08-08 10:18 a.m., Bob Spidell wrote:
> Question for the List: Is it proper to quench--in water, presumably, or
> oil maybe--copper to achieve softness after it's been heated 'cherry red?'
> 
> Bob
> 
> On 8/8/2020 6:43 AM, old dirtbeard wrote:
>> I sort of like your idea about the self-cleaning oven cycle. It would
>> be very even heat, the right temperature, should not hurt the oven. 
>>
>> Maybe just wait to do it while the wife is away for an hour or so...  :-)
>>
>> best,
>>
>> doug
>>
>> On Sat, Aug 8, 2020 at 5:37 AM Pat Horne <patintexas at icloud.com
>> <mailto:patintexas at icloud.com>> wrote:
>>
>>     Pay a local shop with an oxy/acetylene rig to heat them? Muffler
>>     shop, body shop, A/C contractor? A/C contractor sometimes use
>>     air/acetylene. Will that get hot enough?
>>
>>     Peace,
>>     Pat
>>
>>     Pat Horne 
>>     We support Habitat for Humanity
>>
>>
>>     On Aug 7, 2020, at 11:25 PM, Jack Brooks <JIBrooks at live.com
>>     <mailto:JIBrooks at live.com>> wrote:
>>
>>     
>>
>>     I have fabricated a number of 1/8 and 3/16^th inch thick busbars
>>     for an Van RV build electrical system which I am assembling in my
>>     shop.  The busbars are already bent to shape, but I’d like to
>>     anneal them, because the copper was purchased in the  “Half-Hard”
>>     state and making them “Dead-Soft” will insure that they lay
>>     completely flat to maximize the conductivity when I final assemble
>>     the system.
>>
>>      
>>
>>     I usually anneal copper by getting it hot enough to glow with a
>>     propane torch and then allow it to cool.  With the mass of these
>>     busbars, I can’t get them up to a temperature to where they glow
>>     with propane.  An Oxy/Acetylene torch would work, but I don’t have
>>     one.  MAPP gas is hotter, but I don’t think it’s a lot hotter.
>>
>>      
>>
>>     I am considering running them through the cleaning cycle in the
>>     self-cleaning over, as a self-cleaning oven will typically runs up
>>     to around 900°F.  Copper needs 700-1,200°F to anneal, so it should
>>     be fine.
>>
>>      
>>
>>     I’d prefer almost any other solution.  Thoughts?  The last time I
>>     used our oven for a shop project, it was to cure the paint on the
>>     jugs (cylinders) of my ’74 Norton motorcycle.  Mrs. Jack was not
>>     happy.  Copper bars should be fine as they won’t stink up the house.
>>
>>      
>>
>>     Thanks in advance,
>>
>>      
>>
>>     Jack
>>
>>