Ive a friend that is making a replica of the Iron age Battersea shield,
found in the river Thames in Victorian times.
Now he and I have been discussing his problem . That is the original
alloy used was copper tin 90/10. by percentage anlysis.
In other words 9 parts of copper to 1 part of tin by volume
Now he made up his alloy by weight . ie say 18 0z of copper to 2 0z
of tin.
He carefully melted the copper and added the tin, cast his ingot,
cleaned it up and proceeded to hammer it out into sheet.
It always cracked, despite repeated annealing.
So I said because tin is lighter than copper your in fact adding more
tin than 10%.
If you want a 90/10 to finish up with, you have to do the alloying by
parts. Ie volume .
I said you need say 9 1in cubes of copper to 1 1in cube of copper to get
the 90/10 result. He couldnt see that.
Now I put this to the scientific minds on REc. Crafts. Metalworking to
resolve, one way or another which is the right way to make this alloy.
This is not a scam or a troll.
What eventually happened as he had a deadline to finish it I gave him
som 70.30 brass sheet that was the same colour and was ductile enough to
do the replica.
Ted
Frater
Dorset
UK.