Hardening copper

Don Case

Don Case

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I'm making a traveler for the Discovery1789. Once I've silver soldered all the parts together they are very soft because the soldering anneals them. I know that you can work harden copper but it seems contrary to beat this thing with a hammer after all the work I've put into it. Is there another way to harden copper?
 
I have same problems with copper/brass after silver soldering. I try slightly shaping the members with slight moving the members back and forth. The assembly becomes stiffer.
 
Thanks for the pic Jim. It's too bad there is no way to harden copper other than working it. I guess I can try working the ring a bit because it's 26 ga copper and I'm afraid it will deform with just the slightest tension.
 
Don Case said:
Thanks for the pic Jim. It's too bad there is no way to harden copper other than working it. I guess I can try working the ring a bit because it's 26 ga copper and I'm afraid it will deform with just the slightest tension.
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well..., why not use the brass instead of the copper? Yes, that means a re-do, but it will solve the problem. Also, you can use the soldering iron and lead-based solder instead of the torch. Steel is also another alternative, after annealing it will not be as soft as copper.
 
Jimsky said:
why not use the brass instead of the copper?
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Brass becomes same soft as copper after silver soldering.
My experience with solder iron was very upsetting. I was not able soldering anything as I wanted. Main problem was to secure 3 micro small parts so they do not move wen I touch them with iron. This is why I started with silver solder and torch.
If steel can be soldered, the hardness will not be a problem. Could steel be silver soldered? A negative property of steel - it will rust.
 
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Y.T. said:
My experience with a solder iron was very upsetting. This is why I started with silver solder and torch.
If steel can be soldered, the hardness will not be a problem. Could steel be silver soldered? A negative property of steel - it will rust.
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Brass soldering with a soldering iron could be a pain, but... it is all about the proper heat temperature for the given job, and the super-clean surface. Also, there shouldn't be any gaps between parts (even the smallest).

Yes, you can solder the steel (not stainless) with silver solder. Personally, I've done this in the past. The only caveat is to blacken the soldered spot. For blackening metal (steel) I use Perma black, for silver and brass I use Brass black. Perma black will not be blacking silver soldering spots.
 
I suppose that if you dropped it directly from soldering into a pot of water it would get quite hard. Assuming I started with good steel. Piano wire or fishing wire.
 
Don Case said:
I suppose that if you dropped it directly from soldering into a pot of water it would get quite hard. Assuming I started with good steel. Piano wire or fishing wire.
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No...no...it is just as simple as Dark Annealed wire made by Hillman or Tuff Stuff as an example. Any basic wire will do. Why would you need a piano wire? I am not sure how much tension you expect from the rigging.
 
Well. the steel wire will still get annealed from the soldering so it will be soft(ish). Probably nowhere near as soft as copper though. Guess I'm over thinking again.
 
Steel is hardened by quenching it while hot. The opposite effect occurs with copper and its alloys (brass, bronze). The traditional way to harden copper and its alloys is by mechanically work hardening it. That means forming or bending and peening. Silver soldering small copper parts will anneal them almost as much as quenching them because they are small and lose heat quickly to the air by conduction and radiation. There is no practical way of cooling small parts at a rate slow enough to have them retain their hardness, unless you have a kiln with a timer.

You could try carefully bending the small copper parts gently back and forth until the desired hardness in the bend areas is achieved. The softness of copper is the main reason why brass is used instead in ship modeling. In most cases, though, you can get away with using copper.
 
As Kurt touched on, non ferrous metals can only be hardened by "work hardening". How slow you cool will have no effect on their hardness, once they have been reached a certain temperature, the hardness has gone unless you beat or bend the living daylights out of the piece, with the exception of Stainless steel
 
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