No. 2 pencil for sprue plate prep?

Hi, looked but didn't see it. Been a long time and just starting casting again, can't wait. Tom's Accurate 46-405VG arriving today.

This is what I recall: I used a q-tip with mineral spirits to remove any machining oil from all surfaces. Allowed to dry completely. A small amount of beeswax on pins and sprue and handle (bolts? Not sure what to call them), smoked cavities; but also, marked the bottom of the sprue plate and top surface of the mold with a good amount of No. 2 pencil, simple graphite. No oil of any kind, as I've seen a lot.

Haven't found anyone using pencil like this, however. First time prep, anyone doing it this way? Thoughts?

FWIW, Tom's info was that for all his molds they get an US cleaning and scrubbing-out before shipping. For his own use, he blasts with compressed air all his new molds after the lathe and then depends on mold heating itself to simply burn off any liquid contaminants. Anything obvious is just removed with a Q-tip.

I lube with graphite. I lube the whole thing. When I disassemble, I color the pivot pin and alignment pins and sprue plate and mould top and sometimes the mould faces. When casting, if I have a smear, I wipe with a cloth and recolor with a pencil.

For cleaning oil off a mould, I use lighter fluid. I clean the cold mould with it. Then, I get the mould about half temperature and with the sprue cutter open, fill the cavities full with lighter fuel. It boils but doesn’t combust. A hot boiling action cleans the cavities real good it seems.

ya all I ever use is graphite, cover the entire mold as splashes don't stick either. Rapine had it a solution of something fast drying. I have made my own, graphite powder from hobby store in 90% alcohol or more if you can find it. I clean them with a blast of starter fluid from a spray can, qtips if needed.

Thanks guys. First time I see the Ray Pine's Rapine and digging a bit, I see he's retired (good for him). Any sub you guys could recommend, or a DIY recipe? I used to just cover the mold with the pencil, but this seems like a much better way. Saw more here: https://castboolits.gunloads.com/sho...ine-Mould-Prep

I've had good luck with a Q-tip and a drop of synthetic 2 stroke oil dabbed on top of the mold.

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Originally Posted by Winger Ed.

I've had good luck with a Q-tip and a drop of synthetic 2 stroke oil dabbed on top of the mold.

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THis is what I have been doing for years. A barely damp Qtip on the top of the mold, pins & bottom of the spru plate.

Aluminum anti seize and 2 cycle oil with a Q tip.

Thanks guys. Sounds like whether you go the graphite or 2-stroke oil route, none of you guys use beeswax on the pins, then. Just rubbing pencil worked great for me on my previous molds so I picked up some extra-fine graphite powder at our hardware store and I think I'd like to try sticking with that - but am intrigued by the DIY graphite-alcohol solution. Any guideline/suggestion for powdered graphite:90% iso. alc. ratio?

Spray graphite, for those interested;
https://blasterproducts.com/product/...dry-lubricant/

https://www.amazon.com/Tools-Harware...346380&sr=8-18

Strange request to my son. Save me an empty Amsoil 2 stroke oil can next time you change oil. Got many years supply out of first can. LOL GW

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Originally Posted by G W Wade

Strange request to my son. Save me an empty Amsoil 2 stroke oil can next time you change oil. Got many years supply out of first can. LOL GW

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OK, skilled selling point. :popcorn:

Edit: Is there an issue with synthetic?

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Originally Posted by fastdadio

Spray graphite, for those interested;
https://blasterproducts.com/product/...dry-lubricant/

https://www.amazon.com/Tools-Harware...346380&sr=8-18

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Thanks. Saw an old post by Larry Gibson where he just uses a bit on a Qtip (this was Ray Pine's Rapine, when he was making it) and smooths a minimal amount over the pins, top of mold and top and bottom of the sprue plate.

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Originally Posted by huntinlever

Thanks. Saw an old post by Larry Gibson where he just uses a bit on a Qtip (this was Ray Pine's Rapine, when he was making it) and smooths a minimal amount over the pins, top of mold and top and bottom of the sprue plate.

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I have a can of it. Haven't used it on my molds yet, but I'm going to try it. I'm a high pressure steam boiler operator for a large metro area hospital. We've been using this stuff for years to lube valve stems, packings, pump assys, and other high temp light friction applications. Works great for that. We used to use fine graphite powder, but that stuff is messy dirty, smears, and stains everything it touches. This stuff is so much easier to use and live with.

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Originally Posted by fastdadio

I have a can of it. Haven't used it on my molds yet, but I'm going to try it. I'm a high pressure steam boiler operator for a large metro area hospital. We've been using this stuff for years to lube valve stems, packings, pump assys, and other high temp light friction applications. Works great for that. We used to use fine graphite powder, but that stuff is messy dirty, smears, and stains everything it touches. This stuff is so much easier to use and live with.

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Thanks for that info, and your expertise. Do you plan to use it everywhere (incl. the cavities)? Do you think the same issue with the powder exists if it's in solution with the alcohol?

I have no idea what Rapine used. I got my mix from a friend who used it for some aspect of rebuilding pipe organs. Basically you want the finest powder you can get mixed into a fast evaporating liquid. I used 90% rubbing alcohol. It s a little more difficult to find. My stuff does not work as well as the Rapine "mold release". Buy it has never caused a problem that I can detect. It just seems my stuff is not as liquid. I suppose any fast drying liquid could be used. The trick is to get a thin, uniform layer of the stuff on and it drys very fast. Might try paint thinner, brake cleaner, carb cleaner, hot moonshine. I wish I had the Rapine recipe. That was a great product. Also great as a sight blackening or for slip fitting parts to find contact points. I think the spary graphite would e OK for outside a mold buty I can't see getting a nice even layer inside.

ps Rapine is a mold release agent - made to go in the cavities.. I use it on all my molds all over the entire mold. The coating inside is microns thick and you will never see an out of round or off size bullet. The coating is just far too thin. If you have that much, your using WAY TOO MUCH. Someone mentioned denatured alcohol I will try that.

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Originally Posted by huntinlever

Is there an issue with synthetic?

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It can take the high heat without breaking down better than a petroleum oil.

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Originally Posted by fastdadio

Spray graphite, for those interested;
l]

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I've used a little of it.
It makes more of a mess than a 2 year old kid does from eating pancakes with too much syrup.

Used to be a product called lock-eze that is alcohol and graphite. I just use a pencil - it removes any spots of lead - on the sprue plate and top of mold. Nothing in the cavities. I did try eco AC oil. Cooks to a hard non-removable mess.

Like others I use a slightly dampened Q-tip with synthetic 2 stroke oil to lube the sprue plate pivot. I go over the bottom of the sprue plate with a #2 pencil before the casting session. There is one thing that I do with a brand new mold the first time that I use them. (I've only tried this with iron and brass molds, haven't tried it on aluminum) After I've cleaned and de-greased the mold blocks I take a rubber ink eraser (not a pencil eraser - an INK eraser) and lightly rub it against all the sharp edges of the mold cavities. This gently removes the tiny invisible burrs that can cause bullets to stick in the mold blocks when their opened. It doesn't take but the lightest buff with the eraser to have bullets fall out of the molds like muffins, and it doesn't cause any wear on the molds. I flush out the cavities afterwards with lighter fluid to make sure that there aren't any eraser crumbs left behind.

I've pretty much switched to lubing pivot points with aluminum anti seize. Then I use either a pencil or soapstone on the sprue plate, either one seems to work as well as the other, it just depends on which I find first.

Robert

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Originally Posted by Winger Ed.

It can take the high heat without breaking down better than a petroleum oil.

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Thanks Ed.

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Originally Posted by huntinlever

Thanks Ed.

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Oh,,, glad to help.

Taking higher temps. is why it's specified for hot running engines like air cooled 2 strokes and engines with a turbocharger.

Water cooled boat engines don't get that hot and can get by without it.
But now days, air cooled 2 strokes last much, much longer than they used to with just old school oil.

Turbine engines can't run long without it.
It's still expensive compared to old school motor oil.
When synthetic oils were new, and required for jet turbines, even in the 1960s, it was over $30. a quart.
(back when that was a lot of money)

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Originally Posted by huntinlever

Thanks for that info, and your expertise. Do you plan to use it everywhere (incl. the cavities)?
Do you think the same issue with the powder exists if it's in solution with the alcohol?

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No, not the cavities, just the sprue plate, alignment pins, and the top of the mold to prevent galling. I don't have a problem with my boolits dropping out, so not going to try fixing what isn't broke.
Can't say, about the powder alcohol mix, I never tried it.

NOE instructions are to get the mold up to temp and start casting, fill the mold then open the sprue plate, don't open the mold, leave the boolits in the mold. Wipe the top of the mold with a Q-Tip moistened with 2 stroke motor oil. This is the easiest way to not get oil down in the cavities.

Works for me.

Something else to look at while you are oiling your mold:

https://castboolits.gunloads.com/sho...-a-boolit-mold

I have Kroiled the cavities on a mold that did not want to release well. Sometimes it seems to help.

Thanks guys. Moved results from these early casting sessions to a dedicated thread, but wanted to say thanks again. After boring the RCBS handle holes out to 11/64" from 5/32", the handle performs perfectly well (thanks for the note Ed) and they are popping like champs. Just made a thin slurry of 91% isopropyl and the fine graphite powder, applying/letting dry on the mold top, sprue plate and pins, and works well. But I'd like to try the 2-stroke method too, another time.

Have a good weekend all.

I have been using pencils on molds since I started casting in the 90's. Pencils have changed and when you find an old one take it out of circulation and keep it. If is rubbery, doesn't have a graphite center and doesn't smell woody when sharpened write with it.

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Originally Posted by MT Gianni

I have been using pencils on molds since I started casting in the 90's. Pencils have changed and when you find an old one take it out of circulation and keep it. If is rubbery, doesn't have a graphite center and doesn't smell woody when sharpened write with it.

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Good to know, thanks. The ones I have are marked No. 2 but now I'm not sure, wasn't aware they changed them. I ended up creating a thin slurry with the graphite powder and 91% alcohol, and it worked great, but I still prefer the pencil as it's really easy to control what gets hit. Thanks again.

I think carpenter's pencils are still graphite. One of them should last for decades of boolit casting.

Or go with soapstone.

Robert

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Originally Posted by Mk42gunner

I think carpenter's pencils are still graphite. One of them should last for decades of boolit casting.

Or go with soapstone.

Robert

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Thanks Robert. Didn't know that. Got a couple carpenter's pencils.

As far as initial cleaning goes, I’d think being generous with the solvent, especially when rinsing, would remove the most oils, so I scrub with a saturated tooth brush and use a syringe to rinse with fresh acetone or alcohol.

I’m lazy, and found scribbling with a pencil over every surface needing lubrication tedious, so I use two stroke oil on a Q tip or cotton rag for quick application both at the start and during casting. Do be sure that the cloth or swab has only cellulose based fiber if you’re applying lube to a hot mold: a bit of char on the applicator is infinitely preferable to a melted mess stuck on the mold. I do use a carpenter’s pencil while casting to remove spots of lead from the blocks or sprue plate.

I’ve never had much luck with beeswax other than as a reductant. It may be I’m doing it wrong, but even very little put on a hot surface immediately melts and spreads fast beyond where it was intended to go. It burns very easily and can leave stains and residue that I’ve found very hard to remove.

Thanks for the post, Kevin.

You’re welcome.

A couple more things, that may or may not be useful to you, depending on how you plan on lubing your cast slugs and whether they drop freely from the mold.

I also deburr my new molds. The way I learned was to use a softwood popsicle or coffee stirrer stick, with the oil removing solvent wash to follow which will rinse off the wood fragments and burrs. I also use a paint on mold release from HiTek that really helps the bullets to drop freely.

I coat with HiTek, which adheres best to oil free lead. With that in mind, when I reapply two stroke oil (or sprue plate lube, which many suspect is the same thing) over the tops of the blocks with the cavities still filled, those bullets go into the sprue pile to be remelted rather in with the other new casts.

I used to use an old carpenter's pencil, the large flat ones. They had a lot of graphite in the soft "lead". I would scribble all over the sprue plate (top and bottom) and the top of the mould blocks and on the alignment pins. It worked very well for a number of years until I got some Rapine mould prep which worked much better when I applied it with a Q-Tip. Unfortunately, it is no longer made. I make my own now using powdered graphite.

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Originally Posted by Larry Gibson

I used to use an old carpenter's pencil, the large flat ones. They had a lot of graphite in the soft "lead". I would scribble all over the sprue plate (top and bottom) and the top of the mould blocks and on the alignment pins. It worked very well for a number of years until I got some Rapine mould prep which worked much better when I applied it with a Q-Tip. Unfortunately, it is no longer made. I make my own now using powdered graphite.

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That's what I do now, Larry, and your post I came across somewhere here is what informed it, thanks. I still use the carpenter's pencil mid-session sometimes, but really only to dislodge any small bits of lead "plaque" should they pop up, though actually that hasn't happened the last several casting sessions. I warm the mold on a medium setting on a hot plate and I'm dropping good bullets from the start.

I made up a thin slurry with the powdered graphite and 91% iso. alcohol. Can I ask how thin you make up your solution? Mine's really thin (or extremely low density, I should probably say), almost like a solvent "tincture" of the graphite in the alcohol and not a "slurry" in any way.

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Originally Posted by huntinlever

........I made up a thin slurry with the powdered graphite and 91% iso. alcohol. Can I ask how thin you make up your solution? Mine's really thin (or extremely low density, I should probably say), almost like a solvent "tincture" of the graphite in the alcohol and not a "slurry" in any way.

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Last batch I made (a casting buddy here in town talked me out of it....) as I recall I used about 75% alcohol to 25% graphite by volume by eyeball. Mix it in a little semi clear plastic bottle and leave it about 1/4 empty so the mix can be well shaken up prior to use. My last bottle of Rapine mould prep is about gone so I've got to mix some more. Just a few days ago I picked up a small bottle of graphite Lock Ease. It's pretty thin stuff so I've left the bottle open for about half of it to evaporate. Then will try it. Going to order some more powdered graphite though.

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Originally Posted by Larry Gibson

Last batch I made (a casting buddy here in town talked me out of it....) as I recall I used about 75% alcohol to 25% graphite by volume by eyeball. Mix it in a little semi clear plastic bottle and leave it about 1/4 empty so the mix can be well shaken up prior to use. My last bottle of Rapine mould prep is about gone so I've got to mix some more. Just a few days ago I picked up a small bottle of graphite Lock Ease. It's pretty thin stuff so I've left the bottle open for about half of it to evaporate. Then will try it. Going to order some more powdered graphite though.

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Sounds like I'm doing it with much less concentration. So far so good but I'll try the ratio you mention going forward. Thanks.

Reading mold prep instructions for new MP molds, he recommends rubbing a lead pencil on the pins to keep lead from sticking. So, on my new mold I followed his instructions of pre-heating the mold in 3-4 heating sessions and rubbing a lead pencil point on the pins and I had no trouble casting bullets on first try. Bullets just fell right off pins, every once in a while one would hang but just a light tap and it fell right off. So it does seem to have some merit and will continue to use the method myself. I like easy.