Brass mold prep?

[AlaskaMike]

You'd end up having more wrinkled rejects before getting keepers. You can certainly do it that way, but it's quicker and less effort to do the heat cycles as Mal Paso describes.

[Conditor22]

with any new mold you buy!!!!! Ease the leading edge of the sprue plate and check the bottom of the sprue plate for burs!!!!!!!

[mattri]

Interesting

[mfraser264]

No need to smoke the cavities in a brass mold. Brass isn't all that "Sticky" as compared to Aluminum. Having worked in Aluminum foundries, molten Aluminum will stick tightly to bare steal and most any other metal. Smoking Aluminum molds creates a barrier so the two metals cannot come into direct contact eliminating the "Sticking". Brass will naturally oxidize and become dull thanks to the oxygen in the air around us, no worries!!! Leave it on!!! The oxidation is only a tenth of an inch or so thick (.0001"-.0002") yes four places decimals and will not impact the size of the cast bullet. Graphite works well to keep Aluminum from "Sticking". Stay away from the liquid variety. A #2 graphite pencil works great as another member of this forum suggested, my apologies for not remembering who it was. It takes a great deal of time but works very very well. Stay away from the spray on graphite molds preps, it's easy to put too much on and decreace the diameter of the cast bullet and degrade the detail of the casting. Bugger to get off too!

[mattri]

Wouldn't a tenth of an inch be .1"?

[guy_with_boolits]

to smoke or not to smoke is really a meanigless question. you can smoke a mold with a lighter in about 30 seconds so there isnt anything at stake here time wise or difficulty wise. smoke half the cavities and see if it matters.

[rintinglen]

No need to smoke the cavities in a brass mold. Brass isn't all that "Sticky" as compared to Aluminum. Having worked in Aluminum foundries, molten Aluminum will stick tightly to bare steal and most any other metal. Smoking Aluminum molds creates a barrier so the two metals cannot come into direct contact eliminating the "Sticking". Brass will naturally oxidize and become dull thanks to the oxygen in the air around us, no worries!!! Leave it on!!! The oxidation is only a tenth of an inch or so thick (.0001"-.0002") yes four places decimals and will not impact the size of the cast bullet. Graphite works well to keep Aluminum from "Sticking". Stay away from the liquid variety. A #2 graphite pencil works great as another member of this forum suggested, my apologies for not remembering who it was. It takes a great deal of time but works very very well. Stay away from the spray on graphite molds preps, it's easy to put too much on and decreace the diameter of the cast bullet and degrade the detail of the casting. Bugger to get off too!

he meant a 10/th of a thousandth

[mattri]

indeed