The possessed mold!

Attachment 191428

Three consecutive casts from the mold.

Attachment 191429

Boolit in the mold.

Attachment 191430

Opposite side of mold.


This mold is driving me nuts. Front cavity has to be jackhammered out. Both cavities throw nasty boolits at random. I keep getting these tears/voids on the bands at random locations. The mold has been degreased, cleaned, and scrubbed a couple of times. In three days of casting with this mold I have at most 150 useable boolits and very few of those are even close to perfect. If I don't smoke this mold it won't throw a shootable boolit at all. Today I went over both cavities with a hardwood dowel and a pencil eraser. Chased out the vent lines with a Exacto knife. Scrubbed the mold down, heated it up and started casting.

Where am I going wrong with this mold? It's driving me nuts.

Is your alloy fluxed well?

Yes, fluxed three times during smelt, fluxed in pot with sawdust and beeswax.

Heat it up to the point it smears lead across the top and let it cool just enough to stop
smearing. And keep your alloy in the pot cool. I don't know what temperature but I run mine so I can pour and drop bullets all within a 3-5 second time period. But I have to heat soak the mold real well.

Hard to tell but the boolit in the mold looks frosted heavy. If it is, your mold is too hot. That will also mess up the bands. Boolits that stick have not cooled enough to shrink.
A mold too hot will expand at the parting line and get smaller 90° to it. If the block cools a little faster then the lead, it gets a grip.
Then did you put any stick on's in your smelt? Might have a trace of zinc.

The boolit in the mold is one of the three pictured. It's the way the light hits it that makes it look frosted in the mold.

There's no stick ons in the mix.

Quote:

---

Originally Posted by TexasGrunt

The boolit in the mold is one of the three pictured. It's the way the light hits it that makes it look frosted in the mold.

There's no stick ons in the mix.

---

OK, that eliminates that. You still need better temp control. I heat my molds in a little electric box oven on a hot plate with a BBQ thermometer in it to 500° and my Lee pot is set at 750°. I could never cast with colder lead. I am the slowest caster ever but my first boolits are perfect and I can empty a 20# pot without a reject. I even pour, step out the garage to pee and continue to cast perfect boolits.
I think most problems are speed related. I drive my friends nuts and they can never do what I do. The fun thing is I ladle cast and they can't control the left hand when the right tips the ladle off. One turns the mold with the ladle and spills the sprue out. Another has more lead on his garage floor and bench then a pot can hold. I have nothing on my bench.
It will come to you, no hurry. Best advise I can give is to relax.

It looks like the cavity is "wet". What are you using to smoke the mold? Have you smoked it and then used a Q tip to wipe it clear and tried casting? When you chased the vent lines did you go from the mold edge pushing into the cavity or from the edge of the cavity toward the outside of the block?

If you chased the line into the cavity, make a 0000 steel wool Q tip on a regular Q tip and lightly turn the wad of wool as you gently close the mold. Twist it several turns, then reverse and turn about the same number of turns. Repeat in the other cavity. If you cleaning the vent lines caused any burrs, this may remove them. Quit smoking it is not good for your health. I used to smoke my molds but that gave me random issues with size, and sticking bullets. They are clean and work much better.

I still do not like how shinny that mold surface appears, what have you used for lube and did it get in the cavities to cause those voids?

Do like #7 suggests, or a lower temp and a faster pace. Your sprue puddle will tell you if you need to speed up or slow down. Are you pouring with a bottom pour pot and right down the center of the sprue hole or splashing off the sides or missing altogether and trying to finish a pour to make a bullet? Sometimes, it might help to pressure fill the cavity a few times by placing the pot nozzle directly in contact with the plate and fill and over flow a little. Wear gloves because that lead will spurt and given 360 degrees, it will more often find your hand. Sawdust in the casting pot is not a thing I do. You might find dirt specks in the sides of your bullets.

Sometimes the way you open the mold will put a slight twist on the bullets and you will see drag marks on the bands of the casting. The blocks need to be free to move on the handle, but not floppy loose. Try cutting the sprue, wait several seconds, especially if the base of the bullet looks wet, and then as you start to put pressure on the handles to open them, tap lightly on the inside end of one handle to sort of pop them apart.

Did you do a search on "sticking bullets" ? I am sure that there are a lot of threads that have discussed how to open molds when bullets are sticking in one cavity. Good luck. Dusty

Chased the lines from the cavity out. I used a butane lighter to smoke the mold. There's no lube in the mold. Using a bottom pour pot straight into the mold.

This mold is the only one having these problems. I did a few hundred 200 gr SWC from a Lyman mold right before this. Same alloy, same temps.

you maybe got a burr in there somewhere.
take your Q tip and run it up and down and in and out of the edges of the cavity.
either a vent line is rolled over or the edge of a cavity.
I take new molds right out of the box and work the vent lines back into the cavity's and then run my X-acto blade around all the edges of the cavity.
I get quite a bit of resistance in many spots from removing some metal off those edges.

or the design/cut on one of the drive bands is negative.
you might just end up polishing this one, or running it on the cold side.

one other thing it could be is the cavity's are cut slightly off center.
if the boolits are always sticking on one side of the mold I would investigate that.

Several things to do here before the mods start. You want to be sure where the problems actually are, before polishing or removing material. I'm assuming this is a new to you mould. Start by cleaning it very good with solvent then soap and water with a tooth brush. Get all the crud out and down to a clean surface. Let dry well speed it by sitting under a light bulb close. With good magnification look over the nating surfaces alighnment pins and cavities for burrs, light dings, rough surfaces, and other imperfections in the surfaces. A rough surface ( chatter, feed lines, or machine marks) can make a bullet stick pretty tight. Lightly rub cavities and edges with a q-tip if fibers are pulled there is a burr or rough edge. Set a couple bullets into the cavities and a piece of flat stock over them with the depth rod on your calipers measure to the blocks face and repeat on the opposite block. while not a true measurement the difference will be how much the moulds are off center in the blocks. Now with what you've gained here you can start fixing the known problems. A few bullets and lapping with flitz or simichrome will cure the rough surfaces and help with burrs sharp edges and may relieve the occasional under cut surface. Tooth paste works for this also. Shallow vent lines can be scored in deeper with a scribe or awl to help improve venting. Also a very light 45* chamfer on the top edges of the blocks gives a vent line right under the sprue plate. Use a fine stone and just break each corner watching the silver line form when it looks to be .005-.008 wide it should be good. You need the air out before the alloy starts to harden. If possible pre heat the mouldto 350*-400* and have the pot up to 750*. cast fast and pour as full a stream as possible. SOme moulds take a few sessions to break in and cast their best. Some do a heat cycling on the hot plate bringing them up to 400*-450* degrees and letting cool 3-4 times. This helps with the break in and also helps to form the patina in the moulds that aids release.

Pour some Kroil into the cavities and let set for a while and then scrub the cavities with a tooth brush and then go to casting,I believe that you will see a big difference.Molds here are el cheapo Lee molds and they work just fine with out smoking.I use a dab of bullet lube on a q tip to lube the sprue plate piviot point along with some loctite on the screws to hold them tight.

There's no burr. Been all over that mold with a Q-tip. The boolit that sticks always sticks on the same side. I'm wondering if the square cut crimp groove is the problem that's causing the sticky boolit.

I don't think so. I have made my own molds for several years and to center the cherry is a very hard setup. It only takes a few thousands off to get a sticky. I have lucked out but will say it is not easy.
Lathe cut blocks can be even harder to center. It might help to lap some.

I would also recommend the kroil. I put a small drop on a qtip, coat the inside of the mold, warm it up ( doesn't have to be cast temp ), then use a couple quips to get out all the kroil you see. ( It will leave a fine coat inside that you can't see.) I do it to all my molds and it really does help. Only thing is if, as others have posted, that it is more mechanical, your sticking problem ( Burrs, off center cut, negative relief) this won't help.

I put a set of new Lyman handles on the mold today and got it hot and started casting. The handles I had had on it were an old style set of Lyman handles. The new handles hang the mold differently and have much more metal mass in them.

The back cavity didn't have any voids/tears on the bands as shown in the picture.

The front cavity is still sticky but the correct tapping rhythm on the hinge will drop the boolit just fine.

I was able to cast a couple hundred in a decent amount of time.

It sounds like the problem I have with a H&G 50, maybe. Check the pictures on this thread. http://castboolits.gunloads.com/show...29#post3912029

Quote:

---

Originally Posted by TexasGrunt

I put a set of new Lyman handles on the mold today and got it hot and started casting. The handles I had had on it were an old style set of Lyman handles. The new handles hang the mold differently and have much more metal mass in them.

The back cavity didn't have any voids/tears on the bands as shown in the picture.

The front cavity is still sticky but the correct tapping rhythm on the hinge will drop the boolit just fine.

I was able to cast a couple hundred in a decent amount of time.

---

If that is a new mold then the old style handles are not correct for it, as you found. The new style handles are similar to RCBS handles and will not fit old style molds. I have a Lyman 33889 that casts great bullets but I had to track down the correct handles to make it work.

I'm sure of the age of the mold. I picked it up used.