No one is immune

[Mark Daiute]

I've been casting a lot lately.

I think I've come to understand the need for leementing. My Lyman molds have a set screw so I can adjust the sprue plate. The sprue plates on some of My Lee molds have become pretty loose.

ON THE OTHER HAND none of my Lee molds produce fins. My 311299 and 314299's are both making finned boolits. The faces of the mold blocks look fine. I'm wondering now..... I painted the faces with mold prep and I'm wondering if that has lead to the fin problem. I'm going to wash the Lyman molds clean and try it again, see if the problem abates.

In the meantime I'm open to comments.

[Casting Timmy]

Even with my Lyman molds I soot them up just like a Lee mold before casting. You might give that a try and see how you like it.

[mooman76]

Finning comes from the mould not closing all the way.

[longbow]

When you say you painted the faces of the mould blocks do you mean the mating faces or the cavities?

If you painted the mating faces then that may be your problem. The mould prep may be enough to hold the faces apart.

Also, take a look with a magnifying glass (if you haven't already) to check for any small burrs on the edges of the mould blocks or cavities that could keep them from closing. A small machining burr can be enough.

I have had to lap and/or remove small burrs from the faces of several moulds from "big name" companies by using a diamond hone or a piece of fine silicone carbide paper on a flat surface and running the mould over it very gently.

Longbow

[Dale53]

Slamming moulds closed when using can cause burrs around the alighnment pins. Carefully remove the burrs and do NOT slam moulds closed. They must be closed gently. Even iron moulds are relatively soft when hot and the pins slamming into the sides of the alignment holes will damage them.

Dale53

[Mark Daiute]

Slamming moulds closed when using can cause burrs around the alighnment pins. Carefully remove the burrs and do NOT slam moulds closed. They must be closed gently. Even iron moulds are relatively soft when hot and the pins slamming into the sides of the alignment holes will damage them.

Dale53

I would say that this is the culprit. It would appear from careful examination of the molds that they are "hanging up" at the alignment pins. LESSON LEARNED. Now, how do I work, remove any burrs around the pins without ruining the molds.....

And oh yes, it was the mating faces I painted, not the mold portion of the blocks.

Thanks, everyone.

[Dale53]

Mark;
Take a Swiss needle file, fine cut, and CAREFULLY remove JUST the burr.

I was teaching a new caster, one time, went to the basement for a tool, and by the time I got back (3 minutes, tops) he had burred the alignment holesl This was just after I told him to treat a bullet mould like the insides of a Swiss watch.:veryconfu

However, I was able to rescue the mould as described, and he learned a good lesson. He still casts bullets and does NOT slam his moulds shut.

FWIW
Dale53

[Buckshot]

Now, how do I work, remove any burrs around the pins without ruining the molds.....
Thanks, everyone.

..........In addition to what Dale53 mentioned, if the raised metal is right around the perimeter of the hole you can use a 90º countersink (handheld), or if powered be lighthanded with it as cast iron and leaded steel moulds (Lyman) cut easily.

.............Buckshot

[Calamity Jake]

..........In addition to what Dale53 mentioned, if the raised metal is right around the perimeter of the hole you can use a 90º countersink (handheld), or if powered be lighthanded with it as cast iron and leaded steel moulds (Lyman) cut easily.

.............Buckshot

I use a sharp pointed X acto knife to carefully remove the burr