Mold Lessons

[BJung]

I've noticed that if my Lee 6 Cavity mold sticks and doesn't close well, I can tap the part of the handle that connects to the mold and the parts will align.

I've noticed that a hot plate helps keep the mold hot.

I've noticed that if I squeeze the handle end too much there is a light gap between my mold halves and my cast bullets can be thicker.

Are there any unique quirks about molds to share?

[Winger Ed.]

Like any precision tool there is a learning curve, and you have to get used to it, or more nearly learn what it likes.
Once you develop the muscle memory about holding clamped together, pouring, and get a rythm going,
you can really crank out a bunch of boolits in a hurry.

[JonB_in_Glencoe]

I've noticed that if I lube key parts of a mold (with sprue plate lube), that the mold works 100 times better.

Regarding lubing Lee 6 cav molds:
lube the alignment pins, lube the sprue plate bottom, lube the cam (where it contacts the mold) on the sprue plate handle, lube the sprue plate where it contacts the non-hinge bolt, lube the sprue plate hinge bolt, Lube the top of the mold.

Most other molds don't need such intensive lubing, just lube under the sprue plate.

[kevin c]

If you have aluminum gang molds for pistol weight bullets, they can get hotter on one end from always starting the pour on the same cavity. I’ve actually gotten frosting differences one end vs the other, but more common is lead smearing on one end. Learn to alternate the end cavity you start from.

In managing mold temp in an aluminum mold knowing a few different techniques is useful. Besides alternating ends, altering the cadence, the size of the sprue, using active cooling like a wet rag, a fan or a heat sink, leaving the mold open, etc. are all worth knowing about.

[jsizemore]

Every once in a while the mold needs a tune up. Remove the handles and check for any stray alloy that may be on the handles or in the mold slot. I like to use a little antisieze to lube the screws that hold the mold to the handles and in the mold slot. It'll dry out and still provide lubrication. Makes removing the screws easy in the future. A little antisieze on the alignment pins and holes helps too. You just need a little. Same for any screw or setscrew. More is not better. A little on a toothpick goes a long way. A drop of 2 cycle oil to coat the bottom of the sprue plate and top of the mold blocks up to temp and cavities full also helps. Those bullets for the next 3-4 cast and dump cycles need to be recycled back in the pot. I usually do this at the end of a casting session to be ready to go for the next. When it gets warmed up on the hot plate the fresh applied lubes will smoke a bit. By the time your alloy is ready to pour your mold will be ready to go.

I've discovered over time that your grip just has to be just strong enough to keep the mold held and not dangling from your hand.

[Apple Man]

Good timing for this topic.

Two days ago I took my 3 new Lee molds to my buddies house for time on his "healing bench". The molds will throw a log of good boolits in a very short amount of time.

But................The molds need to be worked on some first. If I buy any more they will be disassembled and honed prior to casting a single boolit.

1. The edges of the sprue plate invariably have burs on them and when this is dragged across the top of of the molds, bad things happen.
2. There are burs around the holes drilled in the top of the blocks, carefully remove these with a hone too.
3. Always have some steel wool on the casting bench to remove any minute amounts of lead as soon as it appears.
4. For me anti-sieze made a mess, a SMALL amount of beeswax works well.
5. If the blocks aren't closing check to make sure there isn't a build up. The slightest pressure on the cam handle will have the effects of opening the molds too.

The 6 cavity molds are super cheap and readily available, and crank out crazy amounts in a short time, but they require more care than steel molds too.

[Lion2017]

I've noticed that if my Lee 6 Cavity mold sticks and doesn't close well, I can tap the part of the handle that connects to the mold and the parts will align.

I've noticed that a hot plate helps keep the mold hot.

I've noticed that if I squeeze the handle end too much there is a light gap between my mold halves and my cast bullets can be thicker.

Are there any unique quirks about molds to share?

I had the same isue with my 6 cav. moulds. I had solved it, by drilling 2 holes in the handle, more to the end en closer to the inner side of the mould. (Sorry, no pics) So that the mould can move more in the handle.