Easy way to deburr a Lee 6 cav

[MtGun44]

I have purchased a number of Lee 6 cavity molds, mostly through the
group buys, but some standard designs, too. Generally, with BullPlate
lube I have had very good results, but the deburring so the boolits will
drop easily has been a PITA. Last week at a gun show I picked up a
brass wire brush for a dremel tool, the disk type with the wires in a radial
direction. I used this fine wire brass brush to gently polish and deburr the
edge of the cavities where the cutting tool (boring bar) leaves the burr
when they are machined. The burr takes magnification for me to see in
most cases, but the little dremel wire brush just smooths these burrs off
with a couple of very light passes and no damage to the soft aluminum
mold. I could see that overdoing it would be bad, but the brass is fairly
soft and I chose the finer wire size for less aggressive deburring. I also have
a variable speed controller and ran the dremel at about half speed.

I cast with two of the new molds today - also trying the first time ever without
the soot recommended by Lee. I did scrub them with a toothbrush and Comet,
as per normal procedure.

They both dropped the boolits very easily and showed no ill effects from the
power deburring. YMMV, be careful with those rare GB molds, but it worked
great for me and took maybe 1-2 minutes per mold. :drinks:

Bill

[dubber123]

Sounds like it works well. I have been using a small hand held bronze brush, and brush the edges of the cavities, from the cavity outwards. As you noted, it really seems to help. +1 on the Comet cleanser for cleaning up the moulds. I find no desire to soot up the cavities at all, if they are truly clean, and deburred well.

[Boomer Mikey]

Standard practice with me is to brush all new molds with a soft brass brush to remove the wire edges left in the boring process. I work the cavities both ways from the inside - out, outside - in and across the cavities in both directions to remove the wire edges.

Some of the molds will still stick bullets due to rough edges in the grease grooves. These will eventually work out with use but a little lapping with your choice of abrasive will speed the process up.

Comet cleanser and a toothbrush does a great job of removing the oil and grime.

A standard 82 degree countersink turned by hand in the sprue plate holes will provide the holes with a sharp edge to cut the sprues easily and a file is used to provide a small chamfer on the perimeter of the sprue plate before placing the sprue plate on a flat surface with a sheet of 320 - 600 grit abrasive paper for a few strokes to remove any surface imperfections. The mold blocks get the same treatment... just a few strokes to provide a flat surface for the sprue plate to ride on.

I also take a file to the outside rough edges of the mold blocks to remove the wire edges and inside the mold handle slots to remove the burs on the drilled thru holes.

I use an artist graphite stick to coat the sprue plate and mold top surfaces so lead won't stick to them.

Boomer :Fire: