I keep leading my mold!!??

[Timberland]

I keep leading my mold, what am I doing wrong? its a lee, i sprayed it down with Graphite, I guess it wore off. Right now I have some stuck in the lube groove, before I had it stuck in the joints causing it not to close. I got most off by leaving it in a pot of lead and letting it get real hot, then scrubbing it with a copper brush. I got o propane tourch, it seems to be only good for lighting my cigs. What can I do/doing wrong?

[jdgabbard]

If I were guessing, I would say you had a few rough spots in the mold try the following.

First I would clean your mold REALLY well with some soap and a plastic bristled brush. Try and cast a few more without smoking the mold (I've had issues doing this and found a bare mold works better for me). If your still getting the leading you might try to turn the heat down just a bit. But if it is still leading your mold after that I would go ahead and Leement your mold to remove the rough spots.

[hoosierlogger]

Are the pins are lubed good? My Lee's do that when the lube wears off of them.

[jack19512]

i sprayed it down with Graphite









Why did you spray it down with graphite for? Myself, I have not had to lube my Lee molds at all and they work great. When new I use an old tooth brush and some dish detergent and scrub them good in hot water, that is all I do to them as far as cleaning them. I'm not sure if scrubbing it with a copper brush was a good idea either. Could be just something wrong with the mold but sounds like you went overboard with the prep a little.

[Willbird]

I have only leaded a Lee mold once, and that was by pre heating it too much I think.

[Heavy lead]

If you are scrubbing it with a copper or brass brush you probably are getting copper or brass (small amounts granted) inbedded in the aluminum mould and the lead is attaching it to this as you have essentially fluxing the metal as you are cleaning it so the lead is acting like solder. Myself I hate the darn graphite, I don't let any mould release come within 20 feet of my moulds anymore, if they won't drop right I fix them.

[docone31]

Aluminum is soft, it scratches easily.
It sounds like the graphite, which acts as an anti-oxidant in the mold is clumping allowing the molten metal to "bead" to it. Pushing it off with something makes micro scratches which will allow the molten metal to imbed under it.
It sounds like it has happened a lot. I am guessing there are micro scratches all over the mold.
I did that to one of mine. I use only Lee molds, gotten pretty good at them now.
My reccomendation, slide the sprue plate way off to the side, this is with a preheated mold, place a non-galvanized nut over the cavity, pour through it and let it freeze. Do this to both cavities. Remove intact. Smear some fine valve lapping compound on the casting, just a little, and slowly close the mold, turning with a wrench the casting untill it closes completely. Keep turning the model. Do this with both cavities. Then switch the models untill they spin easily.
You are not trying to recut the cavity, just eliminate any micro scratches.
When I get a Lee Mold, I now let them soak in mineral spirits for days. I always find small flakes of aluminum in the bottom of the cup.
I smoke my molds with a BIC lighter, rather than any carbon depositing flame.
I have found, with the Lee Molds, when they are at proper temperature, the castings fall right out, too hot and they stick hard, too cool and one will stick.
I float my mold in the melt untill my first pour, the sprue takes a while to "freeze". From there, I let it cool down to casting temp.
With my smaller molds, they are tricky at first. The larger ones the issue is keeping the heat low.
They take a touch. I am now very relaxed with my molds, but, I have had to "polish" the inerior on several of them.
I can visualize the frustration! I have one the made wings, wrinkles, stuck, rounded base. Now I know it was me.
I wouldn't mess with the vent broaches. Just the cavity. If the compound is fine enough, you will not notice any size change.
That works for me on those.
After I lap the mold, I just cast through it, tossing the first few back in the pot untill they self clean.
The worst one is now my favourite one.