My First Brass Mold

[Bonz]

Just received my first brass mold, it was built by Mihec. Its looks fantastic and I would hate to screw it up.

Can someone advise me on what I should do with this brand new brass mold before I fill it with molten lead for the first time ?

[rockshooter]

I just cleaned my NOE brass mold before using it, same as any other mold. Make sure you have a mold guide or you will have forearms like Popeye after a while- brass molds are heavy!
Loren

[rintinglen]

It is wise to clean the mold thoroughly, I recommend submersing it in boiling water, then run it through a heat cyle or two before applying lead to it. they are heavy, but boy do they make good boolits. I recently got my 32 ACP hp mold from Mihec, it is a delight to cast with.
I hope yours works as well for you.

[Bonz]

you aren't kidding about the weight, all my other molds are aluminum. Do the brass molds need to be seasoned/smoked like the aluminum molds ? do I need to use mold release ?

[KCcactus]

I don't smoke or season my Mihec molds. If you don't have a hot plate, I would suggest one. I made an "oven" to go on top of my hot plate using a 3lb coffee can, aluminum foil and some wire. When you get the mold to the temperature it likes, you will be smiling from ear to ear.

[Shuz]

Like others have said, just make sure it is clean. I have not seen the need to spray my MP brass moulds with anything. Pin release of boolits can be an issue; but I fixed that by applying a small, real small, dab of the sprue plate lube Miha sends with his moulds, on the pins.

[Teddy (punchie)]

Read more about the Brass molds. What caliber? I had a 227- 75 That was a pain.

So much so that it will be a long time before I buy any brass molds. Some love brass molds, for me I will

use what I have. They all have pro's and con's.

[longbow]

You will definitely need to pre-heat that mould so a hot plate is handy. I cast over a propane stove so use a piece of 3/6" steel plate over a burner as a hot plate. You do not want to over heat a brass mould because they can warp. Not sure if a two cavity is a problem that way but a 4 cavity certainly could be.

I pre-heat mine until the sprue pate lube just starts to smoke. That puts the mould a bit too hot and the first few castings have a molten sprue puddle for a few seconds, once I get going the sprue puddles harden faster and I get into my casting rhythm.

Brass moulds like to be run hot so get into a steady casting rhythm to keep mould temperature up and you should get good boolits. Don't inspect boolits between pours. My Mihec brass moulds cast about the best of anything I own and my Accurate brass mould is right there too.

Some people have reported tinning on brass moulds and it turns out that if you add tin to your alloy you can get tin oxides building up on the mould. There are at least a couple of threads on that and creating an artificial patina to prevent it. I use mostly straight wheelweights or range scrap and have never had a problem but it could happen.

Also, as you are probably aware, brass is softer than iron so can be damaged if roughly handled. Not as soft as aluminum but not as tough as iron.

Is yours a solid boolit or HP Cramer style? If Cramer style there is a bit of a learning curve and some styles of pin tend to have stickers so pins my need to be polished a bit and/or a wipe of sprue plate lube put on them.

Mihec moulds are a class act and I am sure you will like it.

Longbow

[Beagle333]

If it's a 4 cav HP (didn't you get the 9mm?).... you'll prolly notice the blocks don't close completely and you can see light between them after you assemble and install the pins. The guide pins should be screwed into the HP pin finger tight and backed out just a little, to where you can easily spin it back and forth with your fingers. You want a little bit of "wiggle" in the joint, and the blocks will close nicely then. After a good bit of use, they will "seat" and wear the guide holes a bit and then you can tighten them down more, however I have never tightened any MiHec pins all the way and surely don't use the little allen wrench unless they are sticky to remove for cleaning. Happy Casting!


p.s. No smoke.

[Bonz]

You will definitely need to pre-heat that mould so a hot plate is handy. I cast over a propane stove so use a piece of 3/6" steel plate over a burner as a hot plate. You do not want to over heat a brass mould because they can warp. Not sure if a two cavity is a problem that way but a 4 cavity certainly could be.

I pre-heat mine until the sprue pate lube just starts to smoke. That puts the mould a bit too hot and the first few castings have a molten sprue puddle for a few seconds, once I get going the sprue puddles harden faster and I get into my casting rhythm.

Brass moulds like to be run hot so get into a steady casting rhythm to keep mould temperature up and you should get good boolits. Don't inspect boolits between pours. My Mihec brass moulds cast about the best of anything I own and my Accurate brass mould is right there too.

Some people have reported tinning on brass moulds and it turns out that if you add tin to your alloy you can get tin oxides building up on the mould. There are at least a couple of threads on that and creating an artificial patina to prevent it. I use mostly straight wheelweights or range scrap and have never had a problem but it could happen.

Also, as you are probably aware, brass is softer than iron so can be damaged if roughly handled. Not as soft as aluminum but not as tough as iron.

Is yours a solid boolit or HP Cramer style? If Cramer style there is a bit of a learning curve and some styles of pin tend to have stickers so pins my need to be polished a bit and/or a wipe of sprue plate lube put on them.

Mihec moulds are a class act and I am sure you will like it.

Longbow

LOL, actually also my first HP mold - MiHec 9mm 125 gr. brass four cavity HP

[Bonz]

If it's a 4 cav HP (didn't you get the 9mm?).... you'll prolly notice the blocks don't close completely and you can see light between them after you assemble and install the pins. The guide pins should be screwed into the HP pin finger tight and backed out just a little, to where you can easily spin it back and forth with your fingers. You want a little bit of "wiggle" in the joint, and the blocks will close nicely then. After a good bit of use, they will "seat" and wear the guide holes a bit and then you can tighten them down more, however I have never tightened any MiHec pins all the way and surely don't use the little allen wrench unless they are sticky to remove for cleaning. Happy Casting!


p.s. No smoke.

Yep, the MiHec 9mm 125 gr. brass four cavity HP Thanks Beagle333, that was spot on ! But, the mold halves do not have a gap, I can not see light between them. But I will definitely keep an eye out for that.

[Beagle333]

LOL, actually also my first HP mold - MiHec 9mm 125 gr. brass four cavity HP

Uh oh...... you're just now starting your collection? 'Better start saving! Since you only got the one, there's a bazillion others waiting. Join the MiHec "Mold-of-the-month" Club! :mrgreen: