How do you clean a old mold?

[powhs]

I bought a used lyman 44 mold off ebay. It came in today so I loaded a few to see how it would do. I boolits were pitted so I checked closer and found little pieces of lead and trash in it. I cleaned it with steel wool and a brass brush but it still makes boolits with a couple pitts. There is no rust or pitts.

[excess650]

I generally try dishwashing liquid and a toothbrush first. It the crud is really stubborn, I'll try a Brillo pad, but be careful on the edges of the cavities. Sometimes it might be necessary to scrape the bottoms of the frooves with a sharpened nail or some such, but just enough to scrape away, or loosen crud. Follow this with the Brillo pad, dishwashing liquid/toothbrush, and a good, hot rinse.

On aluminum molds I'll just use the toothbrush and dishwashing liquid for cleaning.

Cleanser with the toothbrush might work, and lapping with previously cast bullets and some JB bore cleaner should get anything that remains.

[462]

Scrub it well with Dawn dishwashing soap, hot water, and a toothbrush if it's just crud. Lead specks are easily removed with a brass wire brush, after the mould has been warmed up. Spray brake parts cleaner works extremely well, too.

[MtGun44]

Comet or Ajax with a toothbrush will remove stubborn deposits.

Bill

[geargnasher]

You say pits in the cast boolits' surface? Mould looks clean now? How about little bits of dirt in your alloy causing tiny surface inclusions in your boolits?

Gear

[Mk42gunner]

I have removed light rust from molds by rubbing with a pencil eraser. If you could still find them a typing eraser would probably work better.

Robert

[94Doug]

That's funny, a typing eraser. I remember those. Almost had grit in them. Kind of like the ink eraser on some pens that were marketed. I suppose those are a thing of the past.....

Doug

[462]

...along with carbon paper and flimseys.

[shotman]

Kroil Is all you need

[Suo Gan]

Your using OLD molds??? Everyone knows they don't work for beans...you will need to send them to me so that I can dispose of them properly! Har, Har! You were probably expecting one of those so I chimed in.

I just put them in a pot of boiling water with a little detergent, scrub with a toothbrush and get ready to cast! Er, that is when it gets a tad cooler in the shop anyway.

If you are scrubbing the cavities with steel wool...shame on you sir, you need to be beaten with a wet noodle.

[casterofboolits]

I'm in the process of cleaning a batch of Lee, Lyman, RCBS and NEI moulds that I intend to put up for sale. The cleaning method varies depending on the material the mould blocks are made of. Aluminum or iron.

The Lees were the first molds I purchased in the early 70's and have not used for many moons. I scrub them with a diluted solution of Dawn and a tooth brush. If the stains from smoking or mould prep are a bit stubborn, I then use Comet and a tooth brush and do a final scrub with Dawn to remove the Comet residue.

To remove smeared lead on the sprue plates I use a single edged razor blade and finish with a purple scrub pad from the auto store. Then I stone the bottom of the sprue plate with a hard Arkansas stone. Don't use the razor blade on the aluminum blocks, only the steel sprue cutter.

Lee moulds present a couple of problems particular to Lee. The stamped sprue plates are not deburred and have burrs that can damage the tops of the mould blocks, also the counter sunk holes in the sprue plates have burrs around the holes that also cause damage to the blocks. All Lee sprue plates should be removed , deburred and stoned flat prior to use. The second problem is the self tapping screw used to attach the sprue plate to the mould block which causes a ring of raised aluminum around the screw which will not allow the the sprue plate to lie flat on the mould block. This ring of metal must be carefully filed flat with a fine cut file. Once this is done the sprue cutter will lie flat and make the movement of the sprue plate much smoother.

To remove the screw, I file flats on the head of the aluminum screws and use a wrench to remove the screw. However some of the early single cavity Lee's have hardened steel screws. :groner:[smilie=b:

The razor blade was a suggestion from Hensley & Gibbs to remove lead build up on iron moulds. Make sure to work towards the edges of the cavities so as not damage the cavity edges. Do not use a brass or bronze brush on aluminum mould blocks.

NEI mould prep is particularly hard to remove, but does help to prevent lead build up on the top of the mould blocks and the bottom of the sprue plates.

Use etreme caution when cleaning moulds and always clean lead build up on sprue plates as the mould block will be damaged if you don't. And yes, I learned this the hard way! :oops:

[Mal Paso]

For Iron Molds hobby shops and hardware stores often have displays from K&S Engineering with all kinds of Brass Stock in 12" lengths. I have a 1/4" x 1/32" piece of flat stock that's great on flat surfaces, the edge cleans the vent grooves. I use a 1/16" round filed at an angle to get into tight spots. Brownells has bronze wool and somewhere I found a chunk of brass screen which is a great scrubber. I know this because I've had to scrape inexperience off my molds.