Possible issues with brass mold

[asmith80]

I have two brass MP molds that my lovely wife got me for our anniversary. One is solid the other is hollow point. My first casting session with the a couple weeks ago was great, and I had no issues.

I took them out yesterday to cast some more and I kept running into the same problem with both molds. After I cut the sprue, I flip them over to open, but when I try to open them one or more of the boolits stick, preventing me from being able to cleanly open the mold.

Sometimes if I tap them with my mallet before I open them they come open just fine, but not every time.

I'm casting with both molds at the same time, alternating like I do with my aluminum molds, and I had gotten them pretty hot before the first cast with my hot plate. Not sure if the molds are too hot or what.

Any ideas?

[Flailguy]

Have you lubed the alignment pins?

[asmith80]

I did at the beginning of this last casting session

[trapper9260]

You might have to do it after each use. Also did you treat the inside of the mold also.I have there molds and also others makes and alloy use to make the molds.

[44Blam]

I notice that when I get a mold a little too hot, it won't open until the lead cools a little.
I find that it happens more with larger boolits and when I notice the mold doesn't open, I slow down a little and it tends to help.

[asmith80]

I did have the mold hot enough that the first couple that came out were frosted. I'll try working with a little cooler mold

[asmith80]

So I played around with the HP mold some more yesterday and I was a little more successful. Mold wasn't sticking closed as much as before, but it was still sticking. Some of the problem may be that one or two boolits are sticking to the side of the mold opposite where I have the HP pins, and that's causing some of my problems. I was also getting some fins on the boolits which I suspect came from me not holding the mold shut tight enough.

I started holding the mold by one handle and tapping the hinge until it starts to open on its own when I go to dump them out. It may not be a perfect solution, but at least it helps me keep a steady rhythm instead of having to pause every third or fourth cast