Brass mold prep

[mikedp]

How do I prep a new Mihec brass mold?

[btroj]

Clean it, heat it, use it

[cbrick]

I disassemble it, clean it with denatured alcohol & tooth brush, lube top of blocks & underside of sprue plate & any Cramer HP shafts (not pins) with Bull Plate, assemble & place on hot plate in mold oven. Cast. If you got it up to proper casting temp in the mold oven it will start raining boolits.

Rick

[mikedp]

OK thanks, I was particularly interested in the preheating technique, and does it matter if the sprue plate is left on?

[JonB_in_Glencoe]

I heat cycle my new brass molds as prescribed in the first post. Lots of other good info here too.
http://castboolits.gunloads.com/showthread.php?215409-Brass-Mold-Prepping-Cleaning-Lead-Removal-Patina-amp-Smoking

PS I remove the sprue plate

[dragon813gt]

Spray w/ carb cleaner to remove all residual oils.

Heat cycle three times in toaster oven at 400 degrees for an hour.
http://i198.photobucket.com/albums/aa39/dragon813gt/TimeToMakeAmmo/65F335F0-6F4B-4390-8BDE-423D8A332446-12079-000008F64F3F4754.jpg

I started pulling them completely apart after heat cycling to lube everything. I honestly don't think this is necessary but it takes a couple extra minutes. Heat cycling isn't "needed" either. A few casting sessions will do the same thing. But I've had quite a few molds that you can hear "crying" in the oven. They never do this after the second cycle so the third one is for good measure.

In all honesty you can clean the oils off, lube the sprue plate and cast. Heat cycling starts the patina process w/ no lead present. Water and soap never get anywhere close to my molds. A good solvent like 2+2 will clean the mold in short order.