2 mold issues

[plow]

I'm relatively new to casting and I'm having problems with 2 of my molds. The first is a 311041 that when I open the mold the sprue plat hasn't removed all of the material around the base leaving a wide area of lead over the top of the mold. I'm guessing it is an issue with the sprue plate even though the plate it tight on the mold. |an this be fixed or do I need a new sprue plate? The second is a 357 mold that when opened the top of the mold takes a lot of force to separate. The bottom opens fine but the top sticks. If the mold is empty it opens fine. Any idea what causes this?

[stubshaft]

If you are talking about the base of the boolit being spread out like a thin fin on the base, then it could be a case of a warped Sprue plate. Pics would definitely be helpful here. In the case of the 357 mold it sounds like you have a burr on the cavity. Take or use a loupe or magnifying glass and carefully inspect the parting edges of the mold, a quick pass with an exacto knife will usually be enough to remove the burr. Again Pics would help alot.

[462]

1. The sprue cutter may be too loose, causing lead to flow between it and the top of the mould. There should not be any light visible between the sprue cutter and the top of the mould.

2. The top alignment pin may be extended out too far, causing it to hang up in the hole. Remove the handles, and use a brass drift or punch to lightly tap the pin in toward the mould face. Reinstall the handles and check for proper opening. Repeat the process till the mould opens properly.

[mooman76]

It also may be too tight. Tightening too tight could pull the opposite end up. Try adjusting it and trying it loose, med loose and tight.

[454PB]

I've seen similar things happen when the sprue plate was warped. I recommend you remove it and lay it on a piece of glass (or other flat surface) to see if it's warped. While it's removed, check for burrs or lead build-up.

[MikeS]

How many cavities do the moulds have? If they're either 2 or 4 cavity (or a large block single cavity, having a block size the same as a 2 cavity mould), then sprue plates are available fairly cheap. You can get a mould rebuild kit that has a new sprue plate in it for right around $10.00 or so.