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Casting 925 silver in a cold room?

I have a studio that I use to cast all my jewelry. It is roughly 45 degrees in there and no heater on a 120 circuit is going to warm the room during the winter. Lately I’ve noticed that the thinner rings can become brittle and that maybe the metal is cooling too quickly as I pour from my electromelt. Normally I cast Silver at 1760 degrees (bought from Rio Grande and that is the suggested temperature.)

Is it ok to take it up to 1800 degrees in the winter?

Thanks in advance.

Are you using a casting machine? or just pouring a mold. If you have a furnace you can look into age hardening silver after it’s cast to align the silver molecules and harden the piece

I’m using the ARBE Kaya Cast. What is the age hardening solution? How do I look into it?

I’m using an ARBE Kayacast

Age hardening, otherwise known as precipitation hardening, is a method of using a furnace/kiln to bring the metal to a specific temperature to cause the various components that make up the alloy to fuse in a manner that enhances the Vickers hardness of the metal.

For example, you can precipitation harden Stuller’s Sterlium sterling silver by raising the piece to 600°F and holding it for 30 minutes, then allowing it to air cool. If you search online, you can find various instructions on how to do it for standard sterling. Some require you to anneal the metal first, then precipitation harden it for maximum effect.

Regards,
Ron

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I see. I don’t think that’s my problem. My problem is getting the metal to fill correctly when casting. I may be suspecting that I am not casting it right on my vacuum casting machine. How long should I be pulling vacuum when casting? I don’t leave it on for long. Maybe 10-30 seconds. Should I be holding vacuum longer? I’ve seen some say 2 minutes - 5 minutes which 5 minutes seems extreme.

You can start by increasing your flask temp. I cast silver at 1000F flask temp with no problems. You want to keep the vacuum pressure on until you notice the glow starting to fade in your button.