"Sticky" mold cavity

[anothernewb]

totally new to casting - Recently got the mihec HG68 clone 6 cavity aluminum mold from the group buy.

Only issue is one cavity is really "sticky" I can't get a bullet to fall out of there for the love of anything. I've got a piece of wood to tap the handle with, but that one pesky one literally won't drop a bullet until i actually push the pullet itself. I don't want to go whacking away on the mold itself.

I've smoked the mold to the point where it's blacker than my AR but to no avail.

What are good next steps. I was thinking taking it apart and scrubbing the cavity with a toothbrush or something. but I don't want to make things worse. For now I've just been skipping that cavity when I fill it.

[Minerat]

Does it stick on one side of the block only or both sides ramdomly? It it does the most likely there is a little burr on that side. Take a cotton swab and gently run it around the cavity side that is sticking and the burr will be revealed. You can the remove it carefully with a sharpe exact o knife. They are other methods and others will probably pass them along. Or use the search feature to find past posts on fixing this problem.

[anothernewb]

always sticks to the same side

[JBinMN]

I would guess that either like Minerat mentioned, there is some sort of a "burr",
or you can look at the mold when it is closed & see if the centerline formed by the two mold halves intersects that particular cavity directly in the center or if it is off a bit so that it makes one half cavity a little smaller than the other cavity.

If that centerline is off a bit too much the one side will be shaped more like a "C" than being a mirror of the other cavity , holding the boolit in, which would make the side that releases easier the more "open" leftover section of a "C' to that makes the cavity a complete "O".
The little ")" side being the side which releases easiest and the "C' side traps the boolit in the "C" until you give it an extra push to get it out.

Imagine the letter C and it mating on the other side with a shape like a ")"

C) , and the two mate to make an "O". C) = O , instead of being mirrors of each other.

{ I know they do not match up perfect with using a C & a ), but my artistic skills are limited so I use what I can...}

I am not sure how their molds are made, but if the "cherry" that removes the metal to form the boolits profile is off center from the centerline of the mold when the "cherry" is used, it can create a situation like I tried to describe & "trap" one side of the boolit into the mold.

It only takes a little bit of being off center to create this issue.

(This happened to me on a 2 cavity , btw and I had to return the mold for a replacement, since it was too far off to repair/mod & make it into a decent boolit.)

Anyway, that is another possibility...

G'Luck!
:)

[Grmps]

I hate to be negative about mihec, I hear he makes great molds, BUT; you have a problem like this, the cost and time of sending it back to be looked at are prohibitive.
I wouldn't do "repair" on anew mold, I'd send it back. that said, I don't like the idea of "carving" around the mold cavities.
If the Q-tip test shows a burr (the cavity grabs the q-tip) you can see exactly where the problem is. On cast molds, you rub the edges of the cavities with a piece of wood.
With aluminum molds, I would first give the face of the mold a light "smoothing with a fine diamond hone" this would remove burs sticking out and not marr the face, then set a nut centered over the bad cavity (with the sprue plate out of the way) and fill the cavity and nut with a hard alloy. When your new boolit with nut attached has hardened,put a little toothpaste (or fine polishing compound) on it return it to the cavity and give it a few turns one way, wipe the mold face down (this allows the mold to close all the way) and give it a few turns the other way. This should remove the problem

[RedHawk357Mag]

I take a wooden tooth pic and lightly rub around cavity edges when I get a new mold. I give all molds this treatment. Never smoked a mold in my life. Sounds like a small burr. Just be light handed use a decent light to see what your doing.

Sent from my P00I using Tapatalk

[Dragonheart]

I would suggest getting a strong lope or magnifying glasses to examine the cavity. Try using the eraser on a #2 pencil to polish the edge slightly. Use the pencil lead to coat the inside of the cavity. I agree, if you have to do more than this to a new mold the mold should go back. The seller should stand behind their product at no expense to you.

[Wayne Smith]

Are you saying you have a problem getting all six of the boolits out of the mold? If that's the case drop an e-mail or PM to Miha (Mihec) and he will deal with it.

[anothernewb]

Was out on a motorcycle cruise all weekend, so I haven't had a chance to mess with the mold as of yet, but yeah, one cavity, the same cavity each time - just will not let go of a cast. The other 5 drop with just a little jiggle, most of the time fall out with simply the action of opening the mold. It's a brand new mold, and I am new to casting so I just figured it might me me.

[Wally]

Take a short 3/8" wooden dowel and make a hacksaw cut at one end. Attach some fine 0000 steel wool and spin in a drill on the closed blocks, on the cavity that you are having and issue with. That will polish out the problem for you.

[gwpercle]

After the Q-Tip test , if no obvious burrs turn up . Give the cavities a coat of Liquid Wrench Dry Lubricant , takes two seconds to dry and then start casting . I've helped break in more than one balky mould with this trick. The dry lubricant doesn't contaminate the cavities....it contains no oil. The boolits seem to jump from a dry lubed cavity .
Gary

[glockfan]

Take a short 3/8" wooden dowel and make a hacksaw cut at one end. Attach some fine 0000 steel wool and spin in a drill on the closed blocks, on the cavity that you are having and issue with. That will polish out the problem for you.


got a brass mold made by tom at accurate mold. did couple pass with a wool on one of the cavities which was sticking quite bad. used the magnifier to make sure it was real,obviously there was a little burr along one side ;
rubbed it by hand some, and the problem went away.

at first i tried my luck with those polymer wools,but it proved not abrasive enough to get the job done,so i carefully used the steel wool with success.

a microscopic burr not viewable with bare eyes is able to cause the cavity to
stick ''''unexplicably''''' , till a magnifier identify the culprit.