Subject: Re: Plating

From: Russell McCrackin <[email-masked]>
Date: Wed, 3 Apr 1996 17:27:33 -0800

At 09:47 AM 4/3/96 MST, you wrote:
>> > I have been making a few candle drip pans from salvaged door kick-plate
>> > brass/bronze?  I anneal them by heating in the forge and dunking in the
>> > slack tub in order to raise them cold.  When I quench them, they come
out of
>> > the tub copper plated.
>> 
>> 	This is not a plate as you might think of it.  What has happened is
>> 	that the zinc (and perhaps other metals) has burned off from the
>> 	surface of the material, leaving the copper behind.  This happens,
>> 	e.g., when hard soldering sterling silver.  The copper oxidizes away,
>> 	leaving a very thin layer of fine silver behind.  To me this indicates
>> 	you have used too high a heat.  The dullest red should anneal your
>> 	brass just fine.  in any case you always stand to have some degree
>> 	of this effect manifest itself with brasses.  Buffing should take care
>> 	of it.
>
>I disagree. I think that this is indeed a plating situation. Caveat:
>I'm riding on my high school chemistry, which was awhile back.
>
>   (Snip)
>--
>Steve Smith
>[email-masked]
>
>
Hi Steve.  You can find out for sure.  Just heat a piece of brass to a nice
red heat, but don't quench it.  Just let it air cool.  I did to harden some,
and guess what - it looked like it was copper plated.  

When you heat brass, you can sometimes see a white "smoke" coming off.  Heat
some galvanized nails, you get the same white "smoke."  I have a call for
some "old fashioned" lag screws to fasten some of my forged goods to walls.
I heat and lightly bash the heads to make them look "not manufactured."
I quench them afterwards to keep them hard, but the galvanizing, if there,
burns off with a white "smoke" that I would NOT want to breath!!

Rusty

at Rusty Forge

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