Cleaning a used mold

[calaloo]

I recently purchased an old Ideal mold. The kind with integral handles. It is in very good shape with an excellent cavity. I have cleaned it with brake cleaner, different types of soap (detergent) soaked it in acetone and even heated it pretty hot with a propane torch. It still molds a boolet with wrinkles and poorly defined driving bands. I am beginning to tkink it was maybe treated with silicone or some other such thing. Does anyone have any suggestions?
Bill

[Rockchucker]

You don't mention what temp your alloy is, and some pictures would help also. Try Getting your mold up to temperature, you could be dealing with a cold mold.

[calaloo]

The mold is not cold. Alloy temperature is 800 degrees F. I have molded enough boolets several times for the mold to get plenty hot. Sprue takes 4,5,6 seconds to freeze. Wrinkles are always in the same place. driving bands are rounded instead of square. I am not a novice caster but I have no answer for this.
Bill

[cuzinbruce]

800 degrees is more than hot enough. Too hot maybe. Are you are measuring it with a thermometer? The dial on the side of the pot might not be accurate or calibrated. With the metal that hot, are you getting frosted bullets! Does the metal you are casting with work good in other molds? I have an old Lyman SC that was giving me a hard time. .30 caliber, maybe 200 grains. Long and thin. I found smoking it with a butane lighter helped. I think the carbon holds in the heat and lets it fill out. The acetone you mention should have taken care of any grease, or just about anything else. But rounded bands and wrinkles sounds like temperature. Good Luck!

[LUBEDUDE]

It is not always about temperature.

Sometimes after severe cleaning, you have to run an EXTREME amout of bullets through the mold to "reseason" it for lack of a better word. Maybe someone with better chemistry/science background can explain.

I have done the same thing myself. Hang in there, all of a sudden, good bullets will start coming out.
It once took me 8 hours of straight casting with the same mold after severe cleaning at the same temp before I got good bullets.

I talked to an old commercial caster, and he said I "over cleaned " the mold and had to "reseason" them.
Why this does not have to happen with new molds, I do not know.
Sounds crazy I know.

Good Luck

[Beekeeper]

Calaloo,
I think you are in the right ball park with the silicone in the mold!
I recently bought a couple of old lyman molds that had something in the way of mold release in them.
Took almost 2 weeks of scrubbing to finally get them to cast good.

Finally just put them in my mold oven and turned it on to max and went and watched TV.
Came back several hours later and removed them and let them cool.
Have worked good ever since.
Maybe a good cleaning with barkeepers friend and a good bake off will help.
Hope this helps.


beekeeper

[calaloo]

I tried 750 degrees and 800. The pot is a Waage that I calibrate with my Lee 20 pounder that is PID controlled. Also checked with a thermometer which is 30 degrees low at ~ 800 degrees. The temperature is very close to correct. The boolits are not frosted. Other boolits that I cast are perfect and not frosted either. Alloy is 20:1.

I don't know what Bartender's Friend is even though I am friends with several bartenders. I'm going to buy a hotplate tomorrow and make a mold heater. Been needing one for awhile. Thanks for all the suggestions. Keep'em coming.

[Dan Cash]

calaloo, sell that blasted mould to someone you don't like and stop tearing your hair.

[calaloo]

Dan Cash. Good plan except it is a very hard to find mold that I need. I need to get that sucker to drop a good boolit.

[runfiverun]

it most likely does not have vent lines, and will require a different mindset to casting.
try pressure pouring.
try swirling the alloy in slower.
try shooting it straight in the sprue hole quickly.
try loosening the sprue plate.

[mooman76]

I got a mould like that from someone here. An old Ideal with the handles that don't come off. I have to run the lead with the heat up all the way to get good boolits. Only mould I have that is like that.

[blackbike]

Lap it,
BB

[Sasquatch-1]

Try a thin wood dowel, a piece of cloth and a drill and see what happens. I findthat when I over lube the sprue plate the lube gets down in the mold. I usually just set it in the lead and let it smoke for a while.

Swaging solved that problem. :twisted:

[MtGun44]

Scrub the cavity well with Comet and a toothbrush. This will absolutely get it
clean, and not harm it if rinsed and dried promply. I use max hot water to make
it dry faster.

Bill

[Iowa Fox]

Scrub the cavity well with Comet and a toothbrush. This will absolutely get it
clean, and not harm it if rinsed and dried promply. I use max hot water to make
it dry faster.

Bill

For old stubborn molds I use Zud (same as Comet) and an old tooth brush. You can scrub the heck out of them and not hurt a thing. After the Zud I scub and scrub with hot tap water. Next I scrub with Dawn and the tooth brush followed by clear as hot as it will get tap water with the tooth brush. I then dry with a lint free paper towel.

I think some of the brake cleaners and other solvents actually leave a counter productive residue.

[ShooterAZ]

Scrub the cavity well with Comet and a toothbrush. This will absolutely get it
clean, and not harm it if rinsed and dried promply. I use max hot water to make
it dry faster.

Bill

+1

I aquired a bunch of old molds from a friend who gave up casting. Some had a little bit of rust, and all of them were really, really dirty. Comet and a toothbrush with hot water brought them back to nearly new condition with minimal effort.