Get lead film out of inside of mold faces

[hoppy]

I just got a new Paul Jones mold for a 45-70 410 gr boolit. I have other molds including another PJ mold in a 45-70 540 gr boolit. All my molds have produced great results and the inside faces of the molds are always clean. When using this new mold I got a good amount of lead film on the inside bottom halves of the mold(not in the cavity)!! The boolits came out very nice. I cast with a 20:1 alloy and at 750 to 800 degrees. My question: What is a good way to get the lead out of the inside faces of the mold? Thanks in advance.

[ku4hx]

I've always just gotten the mold good and hot and wiped the face with a folded heavy cloth. Something rough like Crocus Cloth for my ferrous molds. For my AL molds, I use an old wash cloth. But really, this is rare for me.

But I'd question why this keeps happening. If the mold is new, call the maker and see what they have to say. You may have a defect.

[41 mag fan]

750-800 degrees is pretty hot..How hot was your mold?
Is your mold closing correctly or are you having to place it on a board to close like you would a Lee mold?

I had this problem with a Lee and a Miha brass mold I got too hot and my melt was too hot, I used on the Lee a propane torch and a small sharpened dowell rod to remove excess lead

[williamwaco]

These are all good advice and I have personally used all these methods with success.

20:1 is A LOT of tin. ( 4.76% ) I know that is a classic alloy but that tin really makes it flow like water. And you are 150 to 200 degrees too hot. I suspect your alloy is leaking out the bottom of the cavity and flowing between the mold halves. Clean them as clean as possible and cut your temperature down to around 600 and try again.

Also be very sure there is not a tiny imprefection holding the faces apart.


I have never seen or heard of this before so it is a complete guess.


.

[runfiverun]

nice hard to add anything to the above.
hold the mold up t the light and make sure one of the alignment pins isn't holding it open a titch.

[40Super]

I've used a rectagular wooden stick and rubbed the mold faces to get any specks of lead off,then a quick blast with an airhose to get the dust out.

[John Boy]

With a mold up to temperature, rub the inside halves with paraffin which will break the adhesion. Cast a couple of ugly bullets. The paraffin will dissipate and the sticking lead will be gone

Paraffin is also an excellent pin lube and on the sprue plate also. It leaves no hard to remove residue like beeswax does