Author Topic: Sand cast trigger guard  (Read 1311 times)

Offline Scotts180

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Sand cast trigger guard
« on: May 13, 2022, 03:59:24 AM »
I purchased a German silver sand cast trigger guard recently.  After I had finished polishing I noticed it had a slight “twist” from front to back.  My question is, can this be heated and bent to remove the twist.  It appears that just the front flat would have to be straightened.  I’m worried that it may break.  Any advise is greatly appreciated.

Scott

Offline rich pierce

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Re: Sand cast trigger guard
« Reply #1 on: May 13, 2022, 04:11:56 AM »
Like copper or brass or silver, heating to a very dull red and quenching in water or just allowing to cool will anneal German silver. I never bend “white metals” hot.
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Offline Bill Raby

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Re: Sand cast trigger guard
« Reply #2 on: May 13, 2022, 07:31:49 AM »
   Best to let it air cool unless you know exactly what the alloy is. Many alloys will become brittle with quenching. Just about any alloy containing nickel gets brittle with quenching. Not sure if German silver has nickel or not.

Offline Goo

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Re: Sand cast trigger guard
« Reply #3 on: May 13, 2022, 02:27:17 PM »
German silver falls into the category of metals known as non-ferrous (google ferrous and non-ferrous metals).   My experience has taught me as a rule of thumb Non ferrous metals fail when bent or attempted to be altered when they are hot.  Non-ferrous metals should be bent cold, ferrous metals bent hot   If the casting is good then the nickel (german silver) should be ok if you anneal it by heating to a dull red then allow it to cool and quench when the red goes away.     If the casting breaks when you try to take a slight twist out it I would say that you have a bad casting meaning the metal was contaminated in some way.     There are any number of factors that contribute to contamination of metal during melting.   Some of these factors can occur if there is too much oxygen that binds with the molten metal or it has been overheated or some of the alloys in the metal have been reduced.  During investment casting and possibly sand casting you can get a temperature spike that over heats the investment or the sand, it melts the flask material and causes gas to shoot through the poured metal causing porosity, the phenomenon is known as " gassing off".    If you are concerned call the supplier and inform them of your issue ask them if you can exchange the part if the casting fails or would they prefer to send you another part that is not twisted.     
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Offline Dphariss

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Re: Sand cast trigger guard
« Reply #4 on: May 13, 2022, 04:00:58 PM »
   Best to let it air cool unless you know exactly what the alloy is. Many alloys will become brittle with quenching. Just about any alloy containing nickel gets brittle with quenching. Not sure if German silver has nickel or not.

Another name (there are several) for German Silver is Nickel Silver.

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Offline Mike Brooks

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Re: Sand cast trigger guard
« Reply #5 on: May 13, 2022, 04:18:47 PM »
Just give it a tweek cold, you won't break it.
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Offline D. Taylor Sapergia

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Re: Sand cast trigger guard
« Reply #6 on: May 13, 2022, 07:49:21 PM »
It sounds like you don't have to twist the guard far.  You should have no trouble getting it straight twisting it cold.
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Offline Scotts180

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Re: Sand cast trigger guard
« Reply #7 on: May 13, 2022, 11:00:09 PM »
Thanks to all for your advise

Scott