09-05-2014, 02:25 PM
As PixMan said Nickel Aluminum Bronze, it a bearing bronze thats toughs as nails. But it also have a really high shrinkage rate which is the reason for the hot tear.
OldGoaly, the web is already thicker then what its suppose to be by .062, the tear came from hopefully the gate where the metal entered the cavity cooling off too fast. The first one I poured (actually second one) had a big shrink hole in it in the same spot. The actual first one the mold didn't even fill due to the gate being way too small, but I did end up with a nice round 2 inch long hunk of bronze out of it from the riser that I had in the mold.
DA
OldGoaly, the web is already thicker then what its suppose to be by .062, the tear came from hopefully the gate where the metal entered the cavity cooling off too fast. The first one I poured (actually second one) had a big shrink hole in it in the same spot. The actual first one the mold didn't even fill due to the gate being way too small, but I did end up with a nice round 2 inch long hunk of bronze out of it from the riser that I had in the mold.
DA
dallen, proud to be a member of MetalworkingFun Forum since Apr 2012.
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