leaving the last boolits cast in the molds?

[Nefarious Cohort]

Yesterday I was given a couple of molds that belonged to a coworkers dad that recently passed, today I noticed that the molds all still have a cast boolit in them, When I mentioned it to him he told me that his dad always did that to keep the mold from gathering rust or debris while being stored between casting sessions. Is this common practice? or not recommended?

Still being new to this I figured it would be a good question to ask.

Thanks!

[dk17hmr]

Yep, when I get the last bullets out of the pot of lead I leave them in the mold until the next time I get the mold out to cast.

Keeps crap out of the cavities.

[Crash_Corrigan]

If you have high humidity then it is not a good idea. If you store the molds in an ammo can with dessicant to absord moisture then no problem. The moisture can form between the boolit and the mold and you can get rusting on a steel mold.

However I live in Las Vegas where the humidity is usually in the low teens or twenties and having the boolit in the mold would help to identify the mold and be beneficial.

In high humidity areas most guys coat the mold with a preserative coating of oil and then clean the mold prior to use. Keeping the mold and a boolit together in a zip lock baggie would be a nice idea if you had a coating of oil on the mold.

I KEEP MINE IN A PAIR OF 50 CAL AMMO CANS WITH A COUPLE OF PACKETS OF DESSICANT I GOT FROM THE DRUGSTORE {FREEBIES THAT COME WITH THE DRUGS THEY USE AND ARE USUALLY DISCARDED} AND I HAVE HAD NO PROBLEMS WITH EVEN STEEL MOLDS.

The enemy is moisture and it can ruin an expensive mold overnight and you must preserve these for posterity.

[Willbird]

Harvey Donaldson the father of the Donaldson wasp cartridge said that he left a bullet in there because if he did not there was a little paper wasp that would make a nest in there, then the mold would rust, he stored his molds on a nail on his workshed wall. Memory tells me he used oil as well as the bullet to prevent rust.

Bill

[atr]

I always leave the last bullet cast in the mold....I also spray the outside of the mold with
WD40, finally I wrap the mold in cloth and store it in an ammo can with a good seal.....

[jonk]

If I had to degrease the mold every time before casting I'd never cast.

Leaving one in the mold will help keep out some moisture I'm sure but not all.

I don't much care if there is a slight browing over time, I've never had issues with the cavities rusting so I don't worry about it.

[jhrosier]

Leaving a boolit in the mould is better than nothing, but not a guarantee to keep the mould rust free.
I've mentioned this before, but....
I have stored my moulds in one or several 50 cal ammo cans with no protection except a part sheet of vapor barrier paper thrown on top for about 40-some years.
I have never had as much as a speck of rust on any of them. The cans are stored in my basement where I suck 3 gallons of water out of the air per day with a dehumidifier (when I remember to empty it.)
BTW, I don't oil my moulds so they come out of the can dry and clean, ready to use.

Jack

[JohnH]

Oil, in and of itself does not displace water. Oil has a lower specific gravity and will float on water. This means that water will displace oil on a surface. I once heavily coated the cylinder walls of a 6 cylinder engine block with wheel bearing grease and sotred it in a shed in a 55 gallon drum. Three years later, the cylinders were rust coated.

Best method I've used is desicant and ammo cans kept in a temperature/humidity controlled environment. I let teh mold cool and set it in the can, close the lid. As to leaving a bullet in the mold for rust prevention, I think it would work against you, as it would not allow air circulation. Air does get damp and dry. Left open to air movement at least the humidity has a way of ready absorption by drier air.

As an off thought, it would not be difficult to build a vaccuum container. Rust won't happen in a vaccuum. All one would need is an air tight container, a check valve and a vaccuum pump (available at the parts store in manual and electric persuasions) That ought to make the tinkerers wheels turn :)

[jnovotny]

I too store my moulds with a boolit in them. Thats the way I was tought. Never had any trouble with them rusting. Think it may even save them from miss-aligning if they were to be dropped or run over.

[44mag1]

I just spray them with oil then spray them down with brake cleaner when Im ready to cast.

[MtGun44]

I have purchased molds with boolits in them with rusty cavities. It does not
work if you have humidity. In a dry climate (like east KS where I now live) you
can get away with a lot and not get rust on guns and stuff. In central Fla
years ago, keeping guns rust free was darned near impossible in the non-AC
homes I lived in. I'd bet you'd rust a mold for sure there with a boolit in it
and left out in the air.

Ammo boxes with silica gel packs is certain to keep them rust free without the
hassle of degreasing each use.

Bill

[TAWILDCATT]

I leave a bullet in the cavities I have never had rust.and now living in SC,every piece of iron gets rusty,not the molds and now I have added zip locks.I have molda bought in 1945 and there has never been rust.and have Ideal that are not rusted and they must be 70/80 yrs old.:coffee:

[copdills]

I use Lee molds but always leave the last boolits cast in the mold until the next cast:castmine:

[johnly]

I just spray them with oil then spray them down with brake cleaner when Im ready to cast.

That's exactly what I do as well.

John

[FISH4BUGS]

I just spray them with oil then spray them down with brake cleaner when Im ready to cast.

I spray the mould ONLY with WD 40 and wrap them in a plastic bag without a bullet in them. I think that is an old wive's tale about preventing rust.
When I need to use them, I take them out and while everything is heating up. I clean the mould with carb/brake cleaner, and do the cavity with a QTip. It gives the opportunity to inspect the mould closely and do something while the pot comes up to temp.
I DO, on occasion, go through all my moulds and respray and rewrap them.......fondling as I call it.

[Snapping Twig]

Two things cannot occupy the same space at the same time.

My moulds are rusty on the outside due to humidity, I live right next to the ocean in the SF Bay Area and cars here get terminal body rot.

Inside my moulds - sano!

When the mould is pipping hot and I've cast my last, I set it aside loaded and in 25 years I haven't had the cavity of any mould (I have @ 15 moulds, mostly Lyman) rust.

Everyone's results are different and YMMV, but it works for me.

[montana_charlie]

I depend on spray-on graphite to keep lead from sticking to the outside of my moulds, and to prevent wear between the sprue plate and mould top.
I apply two light coats on a cold mould to get the job done, but it doesn't need to be done on every occasion when the mould is used.

If I start to experience 'sticky lead', I will end that session by leaving the last bullet in the cavity when the mould is stored. The fact that it's there will remind me to treat the mould when I use it again...and the bullet prevents graphite from entering the cavity.

I don't allow any substance in the cavity, or on the faces, of a clean mould.
CM

[Nefarious Cohort]

Thank you for all the responses, Humidity really isnt a problem here since its the desert, but I did learn that either way a ammo can seems to be a popular storage container and that makes sense.
I guess if I leave them loaded up and sealed in the ammo can I should be in good shape.

Thanks again,
Nefarious

[35remington]

It's so quick and easy to degrease a mould that I wonder why some guys moan and bitch about having to do so. Incorrect perceptions of the effort it takes to degrease a mould lead some guys to avoid oiling the mould after use, which is not the best way to prevent rust.

It could be that some guys are still wedded to degreasing methods like boiling the mould in soapy water, etc. etc. that seem rather slow and messy and time intensive to me.

Get a good carb cleaner like GUMOUT. Hose down the oiled mould and sprue plate, getting all the surfaces.

You're done.

So there's no reason not to preserve your mould with a good oil, as it's very easily removed.

[catkiller45]

I always spray mine down with WD and wrap in plastic with a rubber band around them.They never rust and some are left this way for a few years.I clean them off with carb. cleaner and thats it..No problems at all....

[Hipshot]

The problem with storing molds in an ammo can is that it holds IN the humidity as well as out. The same thing happens with vinyl gun cases.
If you really want to protect your molds and anything else seal them in a plastic bag with a FOOD VACUUM SEALER the same one you use on your fish and venison steaks !

Hipshot

P.S. If you are worried about the price of the bags just make/buy an extra long bag and when you want to use the mold just cut off the seal and when you are done reseal the same bag! This way you are only loseing an inch or two of the bag, not the whole thing !

[missionary5155]

Good evening
I store all my molds from 2-3 yeras every 4 years or so. I generally cast all the boolits + I will need with a mold(s) then swab them down with whatever motoroil is handy. then wrap in wax paper. These get placed back into their perspective storage box. We made our first trip January 84 and my molds have never shown any rust surviving the humidity of East Central Illinois. I store my firearms, knives, all metal objects the same way.
When it is time to cast Brake Cleaner takes care of the oil in about 5 seconds.
It just works, simple, easy, hardly nothing to buy or pay attention to.
God Bless you all !

[Le Loup Solitaire]

It seems that leaving a bullet cast in a mold works for some people and not for others. I tried that once and I was unfortunate in that it did not prevent rust in my mold so I chose not to use that method. I found that a product called Klenzoil totally prevented any rusting. I coat all surfaces including the screws and threads with it using a small brush and/or a GI cleaning patch, wrap the mold in glad-wrap and put it in a sealable sandwich bag...folded and secured with a rubber band. No Rust. To clean the mold prior to casting, it is of course necessary to remove all traces of any petroleum based product. I soak the blocks in acetone or lacquer / paint thinner, wipe them dry and run a heat gun on them for a few minutes before preheating them. No problems ever with casting good bullets. LLS

[Wandering Man]

I've cast less than 1000 boolits, so I'm still new.

I live on the Gulf Coast, where humidity lower than 60 sends everyone running for saline nose-spray.

After I cast, and the mould is cooler (I"m impatient, so its still pretty hot), I spray with gun oil, then place it back in the plastic box Lyman sent it in. The whole thing goes in my gun safe where I have a desicant pack watching out for all my guns.

Reading some of the above makes me think maybe this is a bit overkill.

Is it?

WM

[longbow]

Not overkill to me.

I have done much the same for the last 35 years or so. Last boolits stay in the mould, but with sprues cut, when it cools a bit but still warm I put a few drops of oil on the sprue plate, at the seams and wipe the outside surfaces. The oil wicks in around the boolits and coats all inside surfaces. Never had a mould rust. Wipe off or use brake cleaner before casting. No problem there either.

Some find the oil a bother to clean off but it doesn't bother me and I would rather clean off oil than rust.

Different strokes for different folks.

Longbow

[Firebricker]

I have pretty good luck leaving moulds full but if i know i am not going to use a certain mould for a long time i put a light coat of gun grease in the cavaty. If you ever get a really bad rust in one cast a boolit in it then drill the base and use a tap chucked in a drill or a dremal with some polishing coumpound on the boolit and close the mould on it. I tried it on an old mould i bought that cleaned it right up.I read how to do it in one of my manuals can't remember which one prob Lyman.