Mold won't drop

[plumber]

I've got a Lyman 358156 that is really testing my patience. Two cavities drop with a tap, one sometimes drops and sometimes needs a beating. The last one won't drop, it has to be pushed out. It does drop for the first 20 or so, but after themold gets hot it won't go. I've tried smoking, kroil, and the spinning bullet in comet. I'm out of ideas.

[Matt_G]

Get out a magnifying glass and check it for burrs.
Sometimes there are burrs where the vent lines hit the edge of the cavity.
You may have to take a small jewelers file to them.

[462]

plumber,

Have you tried liberally spraying the mould with brake cleaner? Dawn dishsoap and very hot water is another cleansing method.

Under a magnifier, check the cavities for burrs, etc.

I've found that smoking a mould is of no benefit.

[oneokie]

Use a cotton swab to test the sharp corners. If strands of cotton are pulled, you have a burr in that location.

Which cavity is the problem? The one closest to the handle pivot? the end cavity? One of the center cavities?

[BSkerj]

What 462 said...I am new at casting and one of the members..Buckshot I think recommended brake or carb cleaner. I used a whole can of carb cleaner on each new Lee mold 6x I purchased and they drop smooth as glass.

[plumber]

The one giving me the most grief is the one closest to the handle pivot (opposite of the sprue hinge) the other one is second to last. I have cleaned it off in boiling soapy water, then used a big can of brake clean. I'll have to try the q tip trick, as I don't see any burrs.

[runfiverun]

the lyman 4 cavs are temp dependent on how they drop i an guage mold temp on some of mine just by how the boolits stick.
one mold sticks then another then they drop out fine,till then i think i am gonna break the tapper stick.
i have taken to leaving the stuck one in the mold till it falls out on it's own.

[waco]

sometimes its as simple as running a fine stone across the face of the blocks.
i have an RCBS 405gc for my 45-70 that i had to BEAT on the hinge pin of the handles to get the boolit to drop
after a light stoning, the problem was solved
hope this helps you
waco

[WILCO]

waco

Dude,

I just noticed you've got a revolver in your avatar pic!!! Sweet!
Guess my eye sight gets better after a few jack & cokes......:shock::mrgreen:

[waco]

lol
love my 44 blackhawk!

[jmorris]

I had one that was sticky and smoke it with an acetylene torch when it starts to act up. They fall out when you open it, no tap required.

[GP100man]

when it gets to temp , if any base splash from loose or warped sprue plate will hold er there tite .

another way to check for burrs is to us a carpenters pencil , you`ll feel it drag on the burr .

magnification required , i like 5x with a lite

[plumber]

when it gets to temp , if any base splash from loose or warped sprue plate will hold er there tite .

another way to check for burrs is to us a carpenters pencil , you`ll feel it drag on the burr .

magnification required , i like 5x with a lite

I never thought of the sprue plate causing the problem. I'm waiting on a sprue and screw kit, that might work.
Thanks, you guys are great!!

[44man]

If a mold is cut with a cavity just a few thousandths off center, one half will not release because the hole is coming around past center.

[mold maker]

I've had 2 Lee 6 cav. that had sprue plates that weren't flat, or had burs. both were fixed by laping them.
I have also decided that smoking caused as many problems as it was supposed to fix, ie, out of round, distortions, lower weight and size, and they still stick. If you can find and fix the problem, it's always better than a bandaid.

[skeet1]

I have a 452460 double cavity that has been a pain in the a$$ since it was new I've deburred it, smoked it and in desperation even used some mold release that I will NEVER ever use again. With recent talk of soaking the mould with Kroil I felt like what have I got to loose. I didn't really soak it but I did use generous amount with a Q-tip and let it sit over night. The next day I started casting and although they still stick a little usually one tap with get them to come out.

Skeet1

[jdgabbard]

Yeah, you can lap the mold, or give the edges a lite stoning. Either one should work for you. I lap just about every mold I own, and as soon as I open the handles they just drop out.

[JSnover]

I've lapped all but one of mine. It's easy to do and it cures a handful of different problems.

[kbstenberg]

By lapping your saying. Take a fine piece of 1000 grit paper or fine file an break the 90degree corner on all exterior corners of the mould?

[plumber]

when it gets to temp , if any base splash from loose or warped sprue plate will hold er there tite .


Thanks a lot for the help gentlemen!!
This headache was cured!!! I replaced the sprue plate and screws and it now drops all 4 with a light tap!! [smilie=w:

[HORNET]

kbstenberg, look up the stickies on "Leementing". Basically, a light lapping of the cavities to remove any burrs left from machining. You may as well check and re-chase the vents first if needed, they also get blocked by burrs.

[JSnover]

By lapping your saying. Take a fine piece of 1000 grit paper or fine file an break the 90degree corner on all exterior corners of the mould?

Nope. Cast a boolit. Drill into the base and install a hex head screw (#6 works well for me). You can turn the drill by hand using a small tap wrench. The screw doesn't have to bottom out. Coat it with 1000 grit clover compound and turn it (by hand or with a drill) inside the mold. I think the Lee-Menting thread has in-depth instructions. Might sound labor-intensive but it's really not after some practice getting the drill on-center and the hole straight. You don't have to be perfect, especially if you use a ratchet and socket to turn the screw. Spin it, spray it out with carb cleaner, cast a few more. I took the plunge about six months ago and could not be happier with the results.