Mold Metals

[Iron River Red]

Have you ever noticed that some of your molds rust easier than others?

I have about 20 molds from Magma and several from Mountain Molds.

The quality of both are great, however the Mountain Molds seem to rust easier than the others.

I have run bullets and left the mold over night and come back first thing in the morning to find the mold has developed surface rust!

The shop is air conditioned and none of the other molds rust that easily.

I usually run 2500 bullets and then switch calibers. Then clean the mold and spray it down.

Is the metal the mold is made from part of the reason? I have adopted the strategy of spraying them down at the end of each day.

I'm wondering if some metals are better suited for molding lead.

Let me hear your thoughts.

Red

[felix]

"Abnormal" rust is caused by high carbon content. Good for hardness, so the mold should especially hold up for auto machine operation. If you want to keep the rust away without spraying, burnish in moly powder all over the mold, including the cavities. After about 50-100 cycles, the mold should be running as perfectly as before. ... felix

[Iron River Red]

What is a good way to perform the burnishing you suggested?

I have a very high quality Moly paste. Could this be utilized?

What about graphite? Will it prevent rust?

Another thing. The surfaces of the molds seems to attract lead. It has a tendancy to develope spots of lead on its surfaces that must be scraped aggressively to remove them. I'm worried that the vent lines and so forth will get damaged from this scraping.

Should I be treating or coating the molds when I first get them?

[buck1]

""--------------------------------------------------------------------------------

What is a good way to perform the burnishing you suggested?

I have a very high quality Moly paste. Could this be utilized?

What about graphite? Will it prevent rust?""
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I'm all ears too!.....Buck

[Bass Ackward]

Another thing. The surfaces of the molds seems to attract lead. It has a tendancy to develope spots of lead on its surfaces that must be scraped aggressively to remove them. I'm worried that the vent lines and so forth will get damaged from this scraping.

Should I be treating or coating the molds when I first get them?

IRR,

I have a mold down in the basement that was sprayed with molly release agent over one year ago to see how long it takes to rust. Still waiting.

Would it be a good idea to treat your molds ahead of time? One year bubba. Is it worth it to ya?

[No_1]

IRR,

I have a mold down in the basement that was sprayed with molly release agent over one year ago to see how long it takes to rust. Still waiting.

Would it be a good idea to treat your molds ahead of time? One year bubba. Is it worth it to ya?

****** Bass,

Leave it to you to come up with a super simple way to protect the molds that requires no clean-up time before use. Just to think I have been using Balistoil all this time. It is a real mutha to clean off and kinda $$$$ too!
I will use to the "Bass protectant program" from now on.

Some time the simplest things are right in front of our face and we never see it till it slaps up.

Have a great day!

[Char-Gar]

I have never had a mold of any kind rust. I have over a hundred molds and have been casting for over 40 years in a very humid climate.

When finished casting, I give the mold a good liberal coat of oil, most often Breakfree, wrap it in clear plastic food wrap and hold that in place with masking tape or a rubber band. Molds so protected can be stored for decades without worry about rust.

When I want to use one, I hold it under the hot water tap in the kitchen sink and scrub it with a soft toothbrush and dishwashing soap. I then use a blow dryer to dry the blocks. A coat of NEI mold prep on Q-tip and I am ready to go acasting. Three or four casts and I am up to speed shucking out boolits.

It takes only a very few minutes to either protect a mold or put it back in service. I can see no reason anybody should have rust in any mold when it is so easy to prevent. Before clean plastic food wrap, I coated the molds with RIG rust preventive grease and that was it. As far as I am concern the old injunction about never putting oil/grease on or in a mold is just an old wives tale.

NEI Mold Prep goes and goes and goes. One itty bitty bottle lasts me 15 years or so. I recently bought two more bottles and that should last me as long as I live. I am 63.

I think if there was some downside to the way I protect molds, I would have run accross it by now.

[XBT]

I handle my molds the same way as Chargar, except I use alcohol to clean them. Before casting I clean the mold with alcohol and a toothbrush, then evenly preheat with a propane torch. I get good boolits right away.

I’ve never had any problems using oil on molds.

[Slowpoke]

I also do the oil ( ATF) and plastic wrap, and I used to do the scrub scrub deal but now its just a couple of pssst psst with the aerosol brake cleaner and I am ready for the hot plate, the stuff works great.

[carpetman]

I dont use a toothbrush on my molds because afterall,they already have cavities.

[fiberoptik]

I dont use a toothbrush on my molds because afterall,they already have cavities.


BOOOOOOOOOOOOOoooooooooo HIiiiiiiiiiiiiiiiiisssssssssssssssssssssssssssssss ss!!

[Iron River Red]

Cavities huh?
Tsk Tsk Tsk!

Can't take him anywhere...

[Leftoverdj]

Easiest for me is a surplus ammo can with VPI paper or tabs in it. I hate to have oil of any kind on my moulds.

[Iron River Red]

I clean my molds after their production run and coat them with the stuff that Magma sells for their molds.

The rust I'm talking about forms in a matter of 6 or 8 hours!

I'm wondering if the quality of the lead alloy has anything to do with it.

I'm running molds for several days and then doing a caliber change. Its the time between loading at night to when we start back in the morning that concerns me.

[Willbird]

Hey Red, your not using marvalux are you ??

that stuff is used improperly (and I always use it that way I guess) will make everything metal in the area rust.

for the amount of work it is taking you to care for your stuff and how much you use it, what about making a gas tight box to put the stuff in and purge it with nitrogen ??


Bill

[waksupi]

Red, I'm with Willbird. That sounds like Marvelux disease.

[Iron River Red]

Never have used the stuff.

I have cleaned up the molds and coated them with one shot case lube and they have been sitting now for a week and no rust.
I'm thinking about checking the rockwell on them and comparing them to the rest of the molds...

[LAH]

Both Drop Out and oil will work. I find the oil easier to remove. The best way I've found to prevent rust is a heated cabinet such as used for the storage of welding rods. No moisture, no rust, plus the mould is ready for instant use. BTW I use no smoke, mould prep, or release while casting.

[Buckshot]

...........Some steels have a more pronounced ability toward rust then others. I'm talking carbon steels and not the high chrome stainless. Most highly alloyed tool steel won't rust under normal storage conditions. The W-1, O-1 and A-2 steel bars I have get handled to cut off pieces, and put back in the racks and they don't show the slightest tendancy to rust.

If a set of steel or iron blocks have a good blue, they'll have a tendancy to not rust also. Some of the methods mentioned could be used to store mould blocks in an aquarium and they wouldn't rust :D That's definative rust protection! Here in So. Calif there isn't too much humidity, althought he past few weeks have seen it pretty bad for that. Yet to date I've had no rusting problems and I do a minimum of protection.

When the blocks have cooled I wipe them with a silicone impregnated cloth. The same one I use to wipe down guns before putting them up. They then go back in their boxes, and that's it.

.............Buckshot