Help With Sticky Mold

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us920669

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I've got a new RCBS cast iron mold that's the worst I've ever had for not dropping the boolits (I like this new word). Sometimes I can't even get the handles apart. I've read about using Comet to polish the cavity - is that OK with cast iron? How about a mild polish like Flitz or Metal Glow?
 
Scrub it out very very well with a toothbrush and Dawn dish liquid and then get it hot. Preheat with hot plate if you have it, and then cast like mad until you get frosted boolits. Don't put the sprues back, don't cull the bad ones, don't admire the good ones, just cast and cast and cast. It should start dropping much easier before it gets to frosted status. I wouldn't imagine that you'd need Comet on a brand new RCBS mold.
 
If you have one of those lighted magnifying glasses, you might drag a Q-tip around the edges of the cavities. It could be you have some burrs left from machining that are holding things together, if so the fibers from the tip will hang up on them.

If this is the case and your REALLY careful with something like a Xacto knife you can simply drag it along the edges to smooth them down. This is of course the last thing you should try. I would follow up with what Beagle posted up as that is the easiest fix that usually works. Out of several dozen molds I have only had to drag a blade on two of them I purchased used, and they were in terrible shape when I got them, how many other hand(s) later....
 
I have gotten some aluminum ones that had that little bit of extra on the edge of the molds that held onto the boolits. I can't say as I've ever seen it on a Lyman or RCBS iron mold...... 'cause I've never had a new one.:o
I always bought mine through some forum or fleabay.:cool:
 
Many thanks. Seems like I spend so much time beating my handles half to death that the mold can't get hot. I don't think there's any edge roughness. I'll melt again tomorrow.
 
The two I referred to both looked like they had been beaten with a claw hammer. I doubt seriously they did them any good using whatever method they used prior to my getting them.

Follow Beagle's advice and you should be good. He seems to buy(acquire) more molds than I do and prolly has more experience with them as well. He does seem to have the only Cast Boolit Hall of Fame that I know of.....:rolleyes:
 
I sure will. It's a 416 350 FN, so I doubt if I could have found a used one. There is one on ebay right now, but the guy wants more than Midway gets for them. It's for my new 416 Ruger toy, or it will be when the barrel gets here. It'll go on a Mauser - don't ask me why. If I go back to Africa I could take it, but I suspect Africa is the rearview mirror for me. I'll prolly just work up some loads & whoop and holler the first couple times it goes off.
 
Comet won't hurt that mold at all. Use the bullet that came out of the cavity. Drill a small hole in the center of it deep enough to insert a screw in it. Coat the bullet with a runny mixture of comet and water and spin the bullet in the cavity with a cordless drill and mold closed tightly. Scrub with water, dry and your bullets will fall freely when you open the mold. I've done this to several of my molds and it works great.
 
Comet won't hurt that mold at all. Use the bullet that came out of the cavity. Drill a small hole in the center of it deep enough to insert a screw in it. Coat the bullet with a runny mixture of comet and water and spin the bullet in the cavity with a cordless drill and mold closed tightly. Scrub with water, dry and your bullets will fall freely when you open the mold. I've done this to several of my molds and it works great. You can do this with lapping compound to enlarge bullets that drop too small also.
 
I did the detergent scrub and cast until the storm front came through, with a possibility of tornadoes. The mold is a little better - it went through a phase of hairy monsters and for a while the blocks didn't align very well, but that all passed and it seemed to settle down after about an hour.
The halves continue to stick together and I found what might be a good system. I pull the handles while walking the mold around on the towel - not banging it at all, just letting its weight thump on the table. Pretty soon it starts to open up at the bottom, and when I see that I start opening and closing it until it pops open and the boolit often falls out or taps out easily. I might do a gentle Comet lap tomorrow.
This is only the second new CI mold I have ever owned, the first being a 44 handgun mold I bought in the 70s. I think it was frustrating at first too, but now its fine, so I guess they all need to be broken in.
Thanks for all the advice.
 
Did you make sure the block alignment pins are clean all the way around them? (no gunk at all where pin attaches to mold) and be sure put just a little sprue plate lube on them as well? For some reason, it sounds like sticky pins... maybe not perfectly lining up with holes.
 
The halves continue to stick together and I found what might be a good system. I pull the handles while walking the mold around on the towel - not banging it at all, just letting its weight thump on the table. Pretty soon it starts to open up at the bottom, and when I see that I start opening and closing it until it pops open and the boolit often falls out or taps out easily.
Click to expand...

I don't think smoke nor comet will help that issue.

The boolits are falling out, it is the misalignment of the pins that is holding the blocks stuck closed.
 
Yup, check the pins.
DONT SMOKE IT. I've smoked a couple molds as a last resort but all that did was fix my lazyness of a good cleaning.
 
Well, I've been busy. One pinway did have a little of their stuff in it, my 6m/m jag fit real tight with a patch so they're clean now, but remember when I was wiggling them open the pin side opened first, and it still does. What holds the mold shut is the boolit, up around the grooves or base. I did a very gentle Comet treatment, not paste but white water and no power, just turned it by hand. I used a cold reject, probably undersize, maybe I'll go back with a bigger boolit and a thicker mix. I cast a little this afternoon - they look good and a few came out very nicely, but it still sticks some so bad I finally gave up cus I'm ruining my handles. The mold is now stone cold, disassembled, and a boolit is stuck in one half. I'm sure I could knock it out, but I wonder if I should leave it in and send it to RCBS.
I tried a lot of things - it's a bottom pour Lee, and I tried removing the mold just as I was shutting off the stream so I could see the last of the lead hit the sprue, and that might have actually helped a little. Maybe that means I have to ladle-pour this one.
 
...when I was wiggling them open the pin side opened first,...
Click to expand...
I'm trying to make sure I understand...
You are healthily tapping the mold hinge w/ plastic/rawhide hammer and the mold still won't open?

...or are you just trying to wiggle it open ?
 
My main problem is bullets wont drop out, and they stick so bad the molds usually don't want to separate. They eventually open one way or another. I found that if I wiggled them they would start to open at the bottom, at the pins, but it was the top - sprue side - that stayed locked. I was saying that if I got them to start to open and then shook them open-close open-close, it seemed to dislodge the boolit from both halves. It doesn't work every time. The real problem is that the mold doesn't let them go, both sides but mainly the sprue side.
 
Tap the hinge while held loosely but still closed.
The mold will open itself at that point.

You may still tap some more to get it to actually drop
from both sides, but that's par for the course.
In fact it's normal.
 
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