Bronze Shrinkage?

How much will a bronze casting shrink?. It will be a sand casting, so
this is strictly about the metal itself, and the difference in size
between poured/hot state and cooled state. What I have is basically
an oval shape the size of a big belt buckle, think of it as a fat
ring, about 1.5" high and about 1/2" thick, with a large, open
center.

Thanks,
Dar

Hello Dar,

How much will a bronze casting shrink?. It will be a sand casting, 

I cast a cross from a 48 inch model and the casting as about 47
inches. This is 0.75 inches thick and cast in Evrdur silicon bronze.
Based on that experience I would say about 2%, but I am pretty sure
that thickness and casting temperature are factors. I would bet your
buckle would shrink less than that.

Stephen Walker

Looking at my shrink rule, I just happen to have handy, about 0.1
mm, not sure how to say that in American inches.

Regards Charles A.

Bronze has about 2% in each dimension.

BTW - for all the bronze casters out there - I create about 3000 lbs
of nice clean chopped bronze scrap a year. Alloy 510 (95% copper, 5%
tin, bit of phosphorus). Melting point 1750F.

I’ve been selling to some local casters at $3/lb, and the local
scrap yard at $2.65/lb.

Jon Daniels
The Ring Lord Chainmail