Hi Paul. Will you answer a few questions for me please? I think
we need to know a few basic facts before advising. 45 mins sounds
like an enormous length of time. You see, with my oxy-propane
torch I melt 30 grams of brass in a matter of 30 seconds, using
an easiflo dry flux, an open 65mm crucible. I successfully cast
melted brass screws in a gravity sand mold.
Here come the questions.
How much brass (grams) are you trying to melt?
What are you melting it in - describe the shape and size.
What flux are you using?
Is your flame oxygen-assisted, compressed air, or plain room
What shape is the brass in? Are they brass screws? Wire?
Sheet? How small? How uniform in size?
Melting point: the liquidus is when the metal is fully
liquid, and the solidus is when it’s fully solid on cooling down.
Regarding temps, I’d say:
metal solidus liquidus
copper 1083C 1083C (1981F)
90/10 brass (gilding metal) 1055C 1070C (1931F)
70/30 brass 920C 955C (1750F)
90/10 bronze 930C 1010C (1850F)
Brass is copper with zinc, and sheet brass is usually 70% copper
and 30% zinc. The zinc boils at 900C so that’s the white stuff
coming off the melting metal and flying round the place. Bronze
is copper alloyed with tin.
Looking forward to your reply.
B r i a n A d a m J e w e l l e r y E y e w e a r
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