Quote:
Originally Posted by RichH
TRUE bronze has nil or trace % zinc ... and is an absolute ROYAL and expensive PITA to machine.
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I don't know of anyone in the marine industry that ever used true bronze with no lead or zinc for machining. Seeing as bronze is a copper alloy I don't even know what a true bronze would be? Perhaps just tin & copper? Considering that nearly every maker of seacocks from Spartan to Apolo, Groco & Buck Algonquin has used 85 three 5 bronze and it is about the most resistant to dezincification we see in the marine world I would have to consider that a good marine bronze. Prop & shafting bronze has a LOT of zinc unless a NiBrAl prop...
As you said very tough stuff even at 85 three 5. I have seen 40 year old bronze seacocks clean up and look like new with no signs of pitting or dezincification and continue on. Well made bronze seacocks will last a long, long time. You can still buy Spartan's but they are getting expensive.
I cringed at the OP discarding those beautiful old seacoks because I have restored ones that looked just like that to near new condition provided there was no dezincification. It is rare that I have seen deszincification on a true 85 three 5 bronze. Verdigris yes, dezincification very rarely...