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View Full Version : Casting pewter bell



robertjenkins
15th Jan 2022, 11:43 PM
Hi
I only dabble in casting but I've had a need to produce small pewter bells. By small I mean about 5cm high. They have to be non-ferrous because the application requires them to be non-magnetic, and since I don't have a foundry, only a domestic stove, they have to be low melt. A few years ago I made some using a RTV rubber mold, and they worked fine, sounded good. I can't remember the exact alloy that I used because I had collected a lot of scrap pewter objects from car boot sales etc.
Anyway, I am now trying to make some more. I am using the same mold but the bells just don't ring, they thud. Now I've read quite a lot of internet advice that says you can't make pewter bells because the metal is too soft. On the other hand, I know I did it successfully, and I also know that you can buy commercial pewter hand bells. So either I got lucky with the material I was using, or there is some technique that I once used, but which I have now forgotten. I suspect it's the material. Has anyone got any tips for what low melt alloy might produce the right ringing noise?
Thanks
R

russ57
16th Jan 2022, 09:48 PM
I think you can heat treat to harden.
Perhaps your original casting process inadvertently, or fortuitously, introduced an annealing process?

robertjenkins
16th Jan 2022, 11:59 PM
I think you can heat treat to harden.
Perhaps your original casting process inadvertently, or fortuitously, introduced an annealing process?
Thanks but I don't think so. I've recast one of the original bells in the same mould and in the same way and it rings. So it must be the metal.

clear out
17th Jan 2022, 10:27 AM
You’ve probably thought of this but what about giving your scrap a tap to see what sounds like. I’d imagine cups or tankards even plates would let you know how dead or responsive the metal is.
I have a mate who’s a guitar maker and he’s always tapping any unusual timber to hear the response.
H.

labr@
19th Jan 2022, 11:46 AM
It's possible that the new source of pewter is from Asia where they have a higher tin content at the expense of the antimony content - about 5% Sb in European pewter, about 1.5% in Asian.

If you can find a source of antimony then you could try adding some to a portion of your stock.

Adding more copper is another thing you could try but if you go over about 1 or 2 % it starts to increase the melt point significantly. Antimony does not have this effect. Have a look at some phase diagrams to get an idea of temperature needed.

Bear in mind that whatever alloying elements you add can't be removed, although if you have a large stock of pewter then you could do trials with small quantities and then dilute the resultant alloy back to close to original composition.

Let us know how you get on.

Edit: Went looking at pewter bells for sale on the net and found this on the Woodbury Pewter site: "CONTENTS: Our Pewter is 92% Tin, 6% Antimony & 2% Copper (No Lead).". They have bells in their range so it would appear that this composition works.