Mold wont drop easily. Help!

[Whiterabbit]

So, I got a new mold. I'm happy!

Except the boolits wont drop out like I want. In fact, they get stuck. REALLY stuck. really really stuck. It's pretty brutal. Can happen to either side of the cavity, whichever feels like being sticky.

So, after getting some old 45 cals to drop years ago, I decided that smoking molds or coloring with a pencil was not the answer to make a mold drop, cleanliness was. But this mold is sticking so badly, I figured I had nothing to lose.

Now, I don't have anything here that will smoke well, and need to buy an oil lamp so I can truly give it a try. Seeking Something that would smoke, I grabbed my oxy-acetylene torch and flipped on the gas. Now, if you have ever used an oxy-fuel torch, you're probably laughing at me right now, and you are right. It smoked alright, but I did not anticipate the amazing mess air-float flake particles will make out of a mold. Anyways, nothing that doesn't clean up well.

Darn if it didn't work though! The (very ugly) bullets did in fact drop like rain for awhile. The more I cast, the better they looked as the mold cleaned up, and the harder they dropped.

I gave up casting for the day.

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I need the wisdom of the tribe. I already know what not to do, like an idiot tried it anyways, did it wrong (knowingly so as well), and only got a temporary half solution. Now the time has come to just get the right info up front and follow it.

I like the bullet and its not an easy mold to find for a good price, so I do NOT want to just sell it and try a new mold. I want to make this one work, come hell or high water.

Suggestions? Put serious effort into "proper" smoking, or is there a better solution for sticky molds?

[Gtek]

Curious-what is mold material? What kind/how big of 45? Alloy? Who made it? Gtek

[randyrat]

I start out with a good scrubbing with Dawn dish soap, then rinse and give it a go...
If the mold has Stick problems then i get out the tooth paste and tooth brush.

If we still have problems then i get out the "Bar Keepers Friend" polishing compound.. Don't scrub so hard that you round any corners just smooth them a bit. Work it parallel with the lube groves.

If that does not work then you need to get a bit more aggressive.

Most of the time Smoke is not needed

[Pb2au]

Most of the time a righteous cleaning with hot water and dish soap will sort out most of your problems.
Check the edges of the cavities for burrs. Most likely you might find one or more. Remove said burr VERY carefully with a light touch with an exacto.

[southpaw]

I have found that most of my molds are a bit sticky untill they get to the right temp. Once I find that temp I try to stay there. Most off them like to be really hot. Another thing I do to a new mold is take a tooth pick and go over any corners to take off any small burrs that might be left.

I do have a couple that I am gonna try Randys tooth paste technique on.

Jerry Jr.

[captaint]

I sometimes take a popsicle stick and gently "rub" the cavity edges. Seems to help get rid of the burrs. Mike

[44man]

I wipe the edges with a piece of Scotch-Brite to remove burrs.
Making my own molds really shows how fast a burr forms. Several of my molds drop boolits as soon as I open them, others not so, so it takes a few taps on the hinge pin.
The only other thing that can cause a problem is the boolit design, not enough draft at the lube grooves or top of the crimp groove.

[osteodoc08]

Hmmm, I had a sticking mold that made some wrinkly boolits over the weekend and took a propane hand held torch to it. I had accidentally got some sprue plate lube in the cavity. Burned it off and was good to go. Heated up the mold at the same time. Win-Win.

[Whiterabbit]

Curious-what is mold material? What kind/how big of 45? Alloy? Who made it? Gtek

not a 45, that was another example. The mold is a 7mm 168 SIL 2 cav from RCBS. Steel. Used mold.

[Shiloh]

What mold?? Aluminum??

Re-read post #3 by Randy rat. I have also boiled my new molds. Take them out of the water immediately otherwise they get a brownish color to them. Reboiling took the color back off.

Then I scrub with COMET of as Randy suggested, Bar Keepers Friend. Boolits fall out of the mold with the gentlest tap if anything at all.
Haven't smoked molds in years.

Shiloh

[243winxb]

Cast at a higher temperature, near frosted boolits . On cooling they shrink more and fall out of mould.

[Whiterabbit]

I'm heating the mold hot enough that the sprue takes longer to cool than my 45 cal ranch dog mold which rains bullets with the same alloy.

I'm sure the sticking is coming from the lube groove area.

I keep barkeep's friend around, you guys use a toothbrush? Tonight ill boil the mold followed by a light toothbrush scrubbing of the mold face and cavities with some barkeep friend slurry, maybe reboil to get that stuff off, and oil it up to prevent rust till next time I cast. If I'm lucky ill be able to cast tonight, but I think that might be a tall order.

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I should mention the boolits come out perfect (ok, maybe the gas check shank is a wee bigger than I wish it were) but no wrinkling, it comes out beautiful. Just, sticky. I'll give it the cleaning, and ill be more anal than I seem to need to be with my 45 and 50 cal molds.

I don't have any sprueplate lube. Do you recommend I color the top of the mold with a pencil after I boil and scrub the mold clean? Or just cast clean?

[fastfire]

What was said earlier, Deburr

[MtGun44]

Scrub with Comet and toothbrush, provides a gentle deburr. If this
does not work, take a cast boolit, drill and put a screw in the base
and put a TRACE of Comet and water in the cavity and spin it with
a drill a few seconds as you close the mold on it. Provides a
very light lapping, usually fixes this sort of a problem.

Bill

[fcvan]

I've been lucky with new molds, 95% Lee aluminum, and a good scrubbing with toothbrush dawn in hot water did the trick. I learned here about new molds with burs causing sticking and started using a wooden probe of some sort to 'feel' and remove slight burs. My wooded probe of choice has become disposable chop sticks from the Chinese buffet. Coleen and paper wrapped, they transfer no oils or other contaminants. I also use them to apply 2 cycle oil to lube the sprue plate and pins, another tip learned here. Back in the day. I smoked molds but haven't had to do that since I learned a thing or two here.

[DrCaveman]

Getting boolits to drop nicely is not something I've mastered
Sprue plate lube, on the other hand, is nicely done with Lucas synthetic 2-stroke

Tried smoking molds...no improvement

Tried lee menting... A little improvement

Dish soap and toothbrush helped a bit

Brake cleaner might have helped, at least I know it got rid of mfgr oils

Altering my procedure has been my only consistent solution
Like, change temp of alloy & mold.
Invert mold prior to opening
Shake mold while cooling
Give the handle screw a few whacks prior to opening

That's all I got, hope it helps

[hickfu]

Brass brush the cavities every now and then..... Brass wont hurt aluminum and it will keep any burrs off the mold.
When ever mine get sticky I use it real quick between casts and they start dropping out.


Doc

[dragonrider]

when I have a trouble some mold I usually give the mold a quick 3 minuit lap with some 600 grit valve compound in each cavity. So far it has corrected all problems with sticky molds. I first use a single edge razor blade to rub across the face of the die at 90 degrees to the face, this removes any burrs on that face and there is always some. 'then the lapping, then clean thougouly and it should stick no more.

[44man]

Cast at a higher temperature, near frosted boolits . On cooling they shrink more and fall out of mould.
Not really true. Boolits are smaller because the cavity gets smaller with too much heat. The mold and lead will still be in a balance for shrinkage.
Yeah, yeah, most think the cavity is a hole and gets larger!

[Iron Mike Golf]

Not really true. Boolits are smaller because the cavity gets smaller with too much heat. The mold and lead will still be in a balance for shrinkage.
Yeah, yeah, most think the cavity is a hole and gets larger!

I think the hole gets larger as the mold temp increases.

See this page: http://physics.stackexchange.com/questions/12599/will-*******-cut-into-a-metal-disk-expand-or-shrink-when-the-disc-is-heated

Ever heat a bearing stuck on a shaft to get to get the bearing off? Heat the bearing, the hole in the middle gets bigger.

[Whiterabbit]

Thus 44man's statement "Yeah, yeah, most think the cavity is a hole and gets larger!"

Wont model that way though because the base of the hole is fixed, and the fact that there is a split in the hole section means it will not follow "washer" convention.

I technically don't know what the answer is but I do know it should model much more like a bite taken out of a square. If I were to model it in 2D, I would draw a square then take a half circle out of the square. What happens to that square under heating? Get uniformly larger just like the rest of the metal? or do the constraints of the metal make the shape change in a different way?

In my head, I would think that since the number of atoms in the semi-circumference of the mold half does not change but expands, that the cavity would have to expand (and not in a circular way, either!), but again that's me thinking out loud.

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[Whiterabbit]

So, I tried casting last night. much better, but still not good. I gave up after 30 good bullets and probably 50 bad ones.

Still needs work. Lots of work. scrubbed it clean, but the brush does not get into the corners of the lube grooves well at all. The sticking is definitely at the lube groove area. Is there a good way to clean those corners? copper wire and a loupe perhaps to scrape out the corners? Something else?

my balls aren't big enough to put valve compound to the cavity yet. No problem on a junker lee mold, but I'm not ready to do that to an RCBS steel mold just yet.

[tomme boy]

Lap the cavities. The steel molds take a lot to hurt them. The alum molds are the ones you really have to be careful when doing them. The lapping compound will break the surface so it is clean and will get rid of any burrs at the same time. Now heat cycle the mold a few times afterwards. The cavities will turn a different color than the rest of the mold. That is what you want. It will look almost like blueing. The more you use it, the better the mold should work.

[MT Gianni]

Get a #2 pencil. Sharpen it and go over the entire mold, sprue plate, top, face and cavities with the point. Next, cut the lead off and burnish the mold with the wooden part of the pencil. If there were any burrs you should have felt them and hopefully removed them. Loosen the sprue plate to the point of self swinging and cast some more.

[Wally]

Make a plug of 0000 steel wool and insert into a drill. Carefully insert in the bullet cavity and spin with the drill....the plug has to be tight. Spin a few seconds and do the other cavity. You will not increase the cavity size, but it will smooth it enough so that the bullets will no longer stick.

[jayjay1]

Reading with big interest.

Very good info here!
[smilie=s:

[44man]

I think the hole gets larger as the mold temp increases.

See this page: http://physics.stackexchange.com/questions/12599/will-*******-cut-into-a-metal-disk-expand-or-shrink-when-the-disc-is-heated

Ever heat a bearing stuck on a shaft to get to get the bearing off? Heat the bearing, the hole in the middle gets bigger.
The cavities are not holes in solid metal. Those get larger. The cavity is half a hole on an edge. Expansion will also have an affect on roundness too. As the block half expands it is moving towards the half cavity.
Once in a while I make a cherry too small and the boolit is too small. I have to get the blocks very hot and put the cherry in and turn with a wrench to remove more metal and enlarge the cavity. I have also found the boolits will be rounder too.
You will not believe how much metal can be removed from a hot mold.

[Whiterabbit]

Another update.

I have the mold casting much better. Not perfect, not good enough to call it don, but much better.

I lapped it. I used a cast bullet and the only compound I have here, JB bore paste (which the internet assured me was acceptable to use). Lapped a little, nothing. Ended up spinning it on the drill for a good 20-30 seconds per cavity. Lube groove area only. Washed well with water, oiled the heck out of it, then completely saturated with acetone to clean it as absolutely best I could before casting. Cast raging hot, heat the mold raging hot.

Seems VERY sensitive to temperature. The cadence of casting has to be perfect, sprues cut at just the right time, and they will fall out. But I almost never hit that window, the timing needed is just too perfect. Has to be pretty fast. Just under the threshold of smearing lead on the top of the mold blocks.

If they don't come out, I've taken to stabbing them with a pick and pushing them out of the cavity, rather than tapping the handles with a wooden block. Doesn't take much effort like this.

It's not perfect, but at least it is castable. Next I think is oil-heat cycling it like a member here suggested, and try again. Followed by more lapping still if that doesn't do it. But I am making progress.




Will need to make a gas check seater for this one for sure. Not a single gas check snapped right on from the beginning, shank always just too big.

[prs]

Smoke as a release agent really seems to not work out well. For sure do NOT use oil or wax driven flame as the smoke, that just puts oil or wax residue in your cavities. A dry hardwood splint can make a nice thin film of clean soot (clean soot? is that oxymoronic?), and a butane lighter can put a very fine soot on the cavities; but, again, smoke is way over rated.
prs

[Whiterabbit]

In my experience, smoke makes an effective tool to release, for about one to two cycles. Then it just gums up the works and causes all sorts of annoying problems. I don't use it since it causes more problems than it solves.

[Walter Laich]

Cast at a higher temperature, near frosted boolits . On cooling they shrink more and fall out of mould.

I never thought of this--have to give it a try.
thanks

[country gent]

Look at the cavities of the freshly cleaned mould with a magnafying lense and see how they look up close and personal. look for a scratch tool mark in the shoulders. Look for rough/uneven surfaces. These shoulders should have some angle to them to aid release of the bullet. Very lightly work cavities over with a new pencil eraser this will smooth burs and burnish the surfaces. If there are areas that show as rough under the magnification use a little JB Bore cleaner to polish on the eraser. Then clean and use a second eraser to finish. Look at the bullets cast for sighns of rough areas square or undercut shoulders and such. Pay close attention to where vent lines enter the cavity as these can form burrs easily.

[Whiterabbit]

I never thought of this--have to give it a try.
thanks

works well for 45's, not so much 7mm. Shrinkage is based on k*x. k is coefficient of expansion, x is the total size of the part. a 3 foot rod expands more than a 3 inch rod, etc.

45's have lots of room to shrink. 7mm, not so much.

[jonp]

Soak it in kroil, pre heat then cast

[jeepyj]

First off good thread.. I'm not making any recommendations but I had a a Lyman 358477 DC that one of the cavities would stick on one side terrible. I used a Dremel tool with a mini buffing wheel with fine polishing compound then re-cleaned and got it to release much easier. All I'm saying is it worked for me quite easy.
Jeepyj

[Whiterabbit]

lapping seems to have done it.

I was trying all sorts of cadence rhythms, timing to pour, timing to cut, timing to drop. Comparing how much force to drop the boolits. Very Very rarely rained boolits, most needed persuasion, but only just. most just needed the smallest coaxing to drop.

And ask I was working on it, tweaking the timing, contemplating that cast, the previous one, deciding how I was gonna change the cadence for the next cast, I realized I had 300-350 boolits around me.

So, I think this problem is solved! Or at least solveable. Solution was lapping for sure, and JB paste was enough.