Mould deburring

[Cleve Branch]

I have a Lyman mould I bought used here. Tried casting and one side would not release the boolit. After some research here, someone mentioned having bur. That is what I found.
How do I remove it?

Cleve

[Maven]

You can use a jeweler's file or a new #11 Facto knife blade, Cleve, but those require a great deal of dexterity. (You don't want to slip!) I, however, prefer to use a new copper bore brush of the proper diameter, chucked in an electric drill, and spun for ~30 seconds in each direction. Btw, a plug of 000 or 0000 steel wool on a warn bore brush will also work (just read about this on the CBA Forum). You'll need to degrease and smoke the mold afterwards though.

[country gent]

Try a pencil eraser. Rub over burr like trying to erase it. Most times this will remove burr with no additional metal removed. A piece of hardwood dowel can do this also. You only want to remove the burr not any actual metal.

[Bent Ramrod]

A copper penny or a piece of sheet copper works too. Rub the edge, not too hard. The copper snags the burr without rounding over the sharp edge of the cavity.

[country gent]

On die segments that had to have a sharp edge remaining we work the edges with a piece of yellow brass to remove burrs and not dull edge. The sharp edge remained but now burrs to cut and break out edge. I question steel wool being spun or brush or dowel as it may round corners and details of the moulds form. Steel wool can be harder than the mould blocks are.

[Cleve Branch]

Thanks every one I will try the penny or brass then maybe an eraser.
Cleve

[Gtek]

I would imagine one would spin wool with blocks closed and held tight. And the following statement of smoking I think is due to taking the surface to the white removing the oxidized finish making sticky. Cold blue vs. smoking also speeds up this process in my experience. I have taken a Q-tip and rub, you will usually find snag area. Very carefully and very lightly rub razor edge at correct angle on area and check with another Q-tip. Being a Lyman with a burr do some research on lapping, might fix a couple things.