Mold prep/storage question

[6.5X284ever]

I will be attempting my first casting soon, had a different mold prep/storage question: I'm assuming the sprue plates are carbon steel (MP, NOE) ? During the degreasing and heat cycling process, do I have to worry about the sprue plates flash-rusting ? If not, do I lightly oil them after I'm done casting, to prevent rust ? If I do this, do I have to start over with the degreasing again next time I cast ? There is alot of great info on mold prep here, but I don't think I have seen this aspect covered.

[HATCH]

They shouldn’t flash rust.
Typically when I am finished with the mold, I coat them (the rust prone items) with synthetic 2 cycle oil.
But to be honest, I have a MP mold that had been sitting in my shop and there is no rust of anything close on it. It had been over ten years since I used it

[Mk42gunner]

I never had any steel sprue plates rust unless the mold was put away dry for several months. Even in humid Missouri summers.

I'm not saying it can't happen, but it is not something I would worry about.

Robert

[gwpercle]

I live in the land of heat , humidity and rust ... For a few decades , after my moulds cool I give all the parts a spray coating of Dry Lube ... the stuff I been using is Liquid Wrench Dry Lube L512 . It prevents rust and can be used as a mould drop-out agent ... No Need to remove it from the cavities ... cast a few boolits and you in business . I use the Liquid in a bottle to apply with a Q-Tip to sprue plate , and top of blocks ... to prevent lead galling and sticking ... The stuff works as a release agent and rust preventitive and you don't have to remove it ... I'm sure any brand of dry lube would work ... I know Liquid Wrench Dry Lube L512 works !
They still make it in both the small liquid bottle and spray can ... I use both !
Gary

[porthos]

after the mold is cool ; i wrap it in VPI paper and store with the other molds in a 50 cal ammo can. i have molds it there that haven't been used in 20+ years and they are fine!!! so, oil them all you want..........

[JonB_in_Glencoe]

I use 2 cycle synth oil for sprue plate lube. as per instructions, I apply oil with q tip. when I am done casting, I wipe the plate with the q tip, leaving a thin layer of rust protection. no need to clean it after storage, I just start casting the next session.

[steveu]

I have been using Kroil on a q-tip this summer and it has been working well.

[Winger Ed.]

When I'm done with a mold for awhile, I spray it down with motorcycle chain oil.
It's an unbelievable mess, and sticks to everything like poop on a baby blanket.

However; I haven't had a mold rust by doing it.

After I had a RCBS Iron mold rust and ruin from rust, I got violent with them.

[414gates]

I spray with a lubricating oil spray because it's easy to apply. I then cover the mould block with plastic. A small jiffy bag if it's just the mould block, or a plastic bag if the handles are attached.

I've noticed rust formation greatly accelerated on uncoated steel being kept near a pool chlorine bucket.

I've also seen a tin of powder go bad and the gas it emits cause accelerated rust formation. Fortunately I store the powder separated from everything else, so no guns were affected.

[ascast]

what porthos said, post #5 \. Cool down - remove handles - 50 cal ammo can with a desiccant of some kind. I have done this for years, like 50 and I get no rust on my molds.
If I leave them out, they get light rust in a couple months.
Get good tight ammo cans - you can store dozens of molds in one can.
some people like the rig-a-ma-role of greasing and degreasing I guess....

[Kraschenbirn]

Dessicant packs are your friend. After use, my molds are brushed clean and the sprue plate lubed before storage in snap-top kitchen containers with a dessicant pack or two in each one. Been doing this for 20-25 years without a speck of rust on anything...including a Lyman Ideal 358156 that I acquired some time in the early 1970s.

Bill

[kevin c]

My unused molds go into ziplok freezer bags with VCI chips, then into ammo cans with a good gasket and desiccant packs.

I should probably mention that I only have aluminum and brass molds, no iron molds at all.

[405grain]

Where I live I have a "casting season". I stop casting from the late Spring until the early Fall because it gets over 100 degrees here in the Summer. Casting in heat like that is no fun, so I generally cast up (more than) enough boolits to last all year in the cooler half of the year. Since I use a trace of synthetic 2 stroke oil to lubricate the sprue plate pivot anyway, when it's time to put the molds up for storage I paint a thin coating of 2 stroke oil on then and put them in their boxes on a shelf. When October rolls around I take the molds that I'm going to cast with and wipe them down with some paper towel, then hose them off with brake cleaner. Once I have the molds clean and dry I give them a squirt with compressed air because (as I've learned the hard way) if there's any trace of paper towel (or anything else) in one of the cavities it will create a dent in the finished bullets.

If you ever do encounter a set of molds that have some light rust on them - don't scrub it off with a wire brush!!! A brass or nylon brush will be OK, but there's few ways that are faster to destroy a nice set of molds than to scrub them with a steel or stainless steel wire brush. Doing that will take the sharp edge right off a set of cavities, and from that day forward you'll have finning or even a ridge on the bullets where the mold halves meet. If a set of molds has rust "pitting" in the cavities it is ruined, and it's time to get a replacement. If there's only "flash rust", this can be easily removed without damaging the molds. One way to remove flash rust is to boil the mold in water, which will convert the "red" rust to "black" rust. The black rust can then be buffed off just like when rust bluing gun parts. Now, all this obviously applies to iron molds. If you have corrosion on aluminum or brass molds that's a whole other kettle of fish, and I'm of no help in that regard.

[lightman]

I agree with the others, the spru plate should not flash rust but it will eventually rust if left untreated. When I finish casting I spray my molds with the same thing I use on my guns. Then I wrap them in a shop rag and store them in an MTM dry box. Thats all of my molds, even the aluminum ones. Before casting I'll degrease them with Brake Cleaner.

[pcmacd]

Try some locksmith grade spray graphite.

It has to have a carrier that will totally evaporate.

You can buy this stuff at home despot.

Iben using it for years as a rust preventative and mold conditioner.

you don't need to smoke the mold, just clean them well with brake cleaner and then spray on the graphite.

It dries in seconds. Great mold release. Great rust preventative. Don't leave home w/o it!

[Gobeyond]

I don’t lube the cavities even on my steel molds. No rust, dry climate. But it might be ok to lube iron mold cavities. I get the impression it’s necessary.