hi jim,
it’s good to see you here! i took a workshop from you @ revere a
few years ago. i was the second one from the corner, do you
remember me (just kidding!)?
for 18k palladium white i take the flask out at 1200F. depending
how i feel that day it will take about 1.5 or so minutes to
melt my charge. with palladium alloy i think the quicker the
better, i don’t have any scientific back-up for this thought
tho. i use no flux on the crucible or the charge, some suggest
using a wesgo type ‘a’ platinum crucible. it’s ok to use extra
oxygen if your palladium alloy doesn’t have any copper (i use a
propane/oxy torch set at 5-8/30-45 respectively). pay special
attention to spruing. get the gold charge hot enough so the
torch ‘chases’ the metal around in crucible. a little extra kick
start or weight on the centerfuge helps because the
solidification of metal happens more quickly than with other
alloy. let the flask cool for at least 10 min. HTH
best regards,
geo fox