Cleaning a Lee mold

[AZPaul]

I started molding .40s with my Lee Micro Ban molds and was doing fine until about 1 hour in to it, then my bullets would not release from the mold with out a sharp smack from my wooden hammer and these aluminum molds can only take so much of that.
What should I do to keep them releasing smoothly?

[MtGun44]

Drill the base of a boolit and screw in a self tapping screw as straight as you can.
Chuck it in a drill and add VERY fine abrasive, spin boolit in cavities with
mold closed to smooth and polish.

Search on Leementing for more and better info.

Bill

[462]

Make sure they are thoroughly clean, remove any burrs that may be present in the cavity areas, and use Kroil (there is a stickie). In addition, you may want to lap the cavities with a mild abrasive, like Bon-Ami.

Ignore Lee's recommendation of smoking the mould...it's not necessary.

[AZPaul]

Should I clean them with MEK or alcohol?
I treated them the first time with Frankfort arsenal mold treatment.

[markinalpine]

Don't ever hit the mould halves directly, especially when they are hot. Only hit the handle pivot bolt. I do have one Lee 6-banger that needs the occasional whack on the side, but I only hit the steel handle, never the aluminum mould itself.
I've always cleaned my Lee moulds with brake cleaner in the outdoors when I got them, carefully de-burred them under an illuminated magnifier with toothpick, sharpened pencils, or other fairly soft tools. Any burrs were near the cavity edges, and could be broken loose with soft implements. I then "polish" the mould faces with a piece of brown paper bag wrapped around a flat piece of wood.
Next, I carefully apply a little bit of Bullplate to the alignment pins, and to the sprue plate hinge.
I pre-heat the mould on a hot plate while the lead is melting in the melter, and apply Bullplate to the top of the mould per the Bullshop instructions.
I haven't needed to smoke or use any other release agent on the moulds.
Maybe I've just been lucky. :bigsmyl2:
After a casting session, I scrub the mould half faces with an all cotton denim rag. I also keep the same all cotton rag handy during the casting session to wipe off any lead that might stick to the mould half faces.
Hope this helps,
Mark :coffeecom

[462]

I use brake parts cleaner to get rid of most of the junk, followed by a toothbrush and Dawn dish soap and hot water, blow dry using a compressor, then a bit of Kroil. One member soaks his moulds for two days in mineral spirits. The bottom line is you probably can't clean them enough.

Lee moulds perform better when the alloy is very hot. I turn the thermostat all the way up and cast until the boolits start to get frosty, then go to a lower setting until the frostiness disappears.

Edit added: markinalpine makes an excellent point about Bullplate. I do the same thing, but use Permatex Anti-Sieze, instead.

[stubshaft]

???? Why did the mould give him problems after 1 hour???

I have a numbr of Lee moulds as do most other members here. I don't remember any of them giving me problems after the fact.

[dromia]

Probably after an hour the temp had increased and there was better fill out making the boolit grip any burrs more?

I boil my moulds for 10 minutes or so with a couple of drops of detergent in the water.

[Bret4207]

First off, I don't like the various "mold release" type products or smoking. It insulates the mould from needed heat and reduces the diameter of the boolit. The Frankford stuff is useless IMO, but it does make a fair lube for sliding surfaces that you don;t mind being covered in black goo.

A couple things come to mind-

#1- Could be you have some lead build up in the cavities that is holding the boolits from releasing.

#2- Could be some buildup on the mating surfaces causing the blocks to misalign and making the boolits stick.

I would give the blocks a good scrubbing with a stiff brush, like a fingernail brush or maybe a brass brush like comes in the welding kits, in good soapy, hot water. Then I'd go over the mould using a magnifier of some type looking for flashing or lead build up. Many times this stuff can be scrapped off with a small stick like a tongue depressor or popsicle stick or a pencil. Something is causing the problem and usually once you find it it will be obvious.

[AZPaul]

Now that I think about it, the lead just fell off the out side but yet the bullet would not release.
They probably need a good cleaning.

[DEVERS454]

Removing burs is key if the mold is rather warm.

Another thing to look at is to clean it with Acetone and then wipe it down with rubbing or other denatured alcohol.

Acetone will remove any of the slag that might have gotten stuck to the walls w/o corroding the mold.

[stephen perry]

Paul alcohol is a beginning and finishing rinse. More needs to be done in the middle to clean a
mold. I clean a new or new to me mold once in the beginning.
After I start casting with a mold I brush it off as needed but that's it.

All the info on LEE molds here is good. I like 462's approach it is similar to mine.

Stephen Perry
Angeles BR :brokenima