Cool! (so to speak.) I would have thought more insulation would have
been required, but it sounds like that is sufficient.
Donald.
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On 2020-08-08 6:50 p.m., Jack Brooks wrote:
> Insulation - BINGO! Great thought Donald!
>
> I underestimated copper's heat transmission rate. Using propane, I could not
> get a 1/8 x 1 inch x 8 inch bar to get to glow with the bottom of the bar
> clamped in a vice. I decided to try "Insulating".
>
> I laid a 3 inch long copper bar (typical busbar length) across the teeth of
> two sections of a coarse hack saw blade clamped off to the side of my vice.
> There is almost no contact between the copper bar and these supports, only
> across the tips of the teeth on the two halves of the hack saw blades, so
> maybe a dozen pinheads. With this arrangement and with a partially-dark
> room, I could just barely see the red glow in the copper. After a quench, the
> copper bar was soft!
>
> I now have a method. Now I have to insure that I can clean up the contact
> surfaces well without affecting the flatness and I can go forward with
> softening the real busbars.
>
> Thank you everyone for a fun adventure in learning,
>
> Jack
>
>
> -----Original Message-----
> From: Donald H Locker <dhlocker@comcast.net>
> Sent: Saturday, August 8, 2020 10:14 AM
> To: Jack Brooks <JIBrooks@live.com>
> Cc: shop-talk@autox.team.net
> Subject: Re: [Shop-talk] Annealing Copper bars
>
> The temperature that the copper reaches is controlled by the rate at which
> the heat escapes it vs the rate at which heat is added to it, and finally by
> the temperature of the flame.
>
> An oxy-fuel torch adds heat quickly, so the rate at which it is lost is less
> of a problem. Propane/air is not as hot as oxy/fuel, but they're both plenty
> hot enough.
>
> I would expect a propane torch to do OK as long as your copper bar is
> reasonably well insulated from the outside world - how about [nearly] burying
> it in vermiculite? Add heat in the middle with the rest of the bar pretty
> well buried and it should get reasonably hot throughout. You could use a
> Tempil Stik or an IR thermometer near the ends to see when it has heated
> sufficiently.
>
> It would be easy enough to then pick up the bar with pliers or tongs and dunk
> it.
>
> At least I'd try that before tempting the fates with Mrs. Jack's oven.
> Donald.
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>
> On 2020-08-08 12:06 p.m., Jack Brooks wrote:
>> I disagree to some extent on the water/oil quench vs. air cool, from
>> text and experience. Iâ??ve done both with oil pan drain plug washers
>> and while there may be a difference, itâ??s minor making the two methods
>> interchangeable in my experience, especially if I am trying to go from
>> half hard to a softer condition.  A quench is the ultimate way to
>> soften, but just getting it up to temperature makes a huge difference
>> in hardness.
>>
>> Â
>>
>> https://en.wikipedia.org/wiki/Annealing_(metallurgy)#:~:text=In%20the%20case%20of%20ferrous,quickly%20by%20quenching%20in%20water.
>>
>> https://www.wikihow.com/Anneal-Copper#:~:text=You%20quench%20carbon%20steel%20to,the%20resulting%20crystalline%20structure%20is.&text=So%2C%20to%20anneal%20a%20hardened,heating%20it%20red%20anneals%20it.
>>
>> The question remains, lacking an Oxy torch, thoughts on the clean
>> cycle of a home over or any other suggestions? I may talk with my
>> body guy about using his Oxy torch. That was a good suggestion.
>>
>> Thanks,
>> Jack
>>
>> *From:* Shop-talk <shop-talk-bounces@autox.team.net> *On Behalf Of
>> *Pat Horne
>> *Sent:* Saturday, August 8, 2020 8:44 AM
>> *To:* John Innis <jdinnis@gmail.com>
>> *Cc:* shop-talk <shop-talk@autox.team.net>
>> *Subject:* Re: [Shop-talk] Annealing Copper bars
>>
>> So, referring back to the OP about using the oven to anneal the bars,
>> it WOULDNâ??T be a good choice.
>>
>> Peace,
>> Pat
>> Pat Horne
>> We support Habitat for Humanity
>>
>> On Aug 8, 2020, at 10:03 AM, John Innis <jdinnis@gmail.com
>> <mailto:jdinnis@gmail.com>> wrote:
>>
>> This matches my understanding as well. Brass and copper soften when
>> quenched. Steel and Aluminum harden when quenched.
>>
[snip]
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