For the Iron Mold casters

[Seeker]

I just bought an RCBS mold from Leadlubber Thank you sir!
I have and use about 12 different aluminum molds, all Lee and they make excellent bullets. I've been casting my own long enough that once I get everything warmed upped, I'm casting good bullets most of the time with the first ladle pour. My question is.....what can I expect out of this rcbs iron mold as far as getting used to it and are they that much different. Thanks for reading and I genuinely appreciate any responses. G.

[Winger Ed.]

I think you'll find it's 'smoother' somehow, and not being finicky- it wants to cast good boolits.

Not that they're bad, however;
once you get used to it, you might find it hard to look at the Lee molds the same way again.

Molds are a tool. Like any other tool, once you've used the good stuff, it's hard to go back.
So far, I haven't known anyone to to say, "I sure like that bargain priced tool better than the real expensive one".

[john.k]

Youll quickly find out how heavy it is compared to a Lee..........lot better made for sure .....you can take the handles off ,for one thing.........but then handles are extra cost item.........will it cast better bullets? ..IMHO....No!..........I might add,Lyman molds are now steel ,not cast iron,and the worst mold I have ever used was a new Lyman ......the bullets simply stuck to either half like glue.

[Mk42gunner]

It will probably take a bit longer to heat up, but that's not necessarily a bad thing.

Every RCBS mold I have used (I own five or six) has been easy to cast with. Not quite H&G easy, but better than most other common brands.

Robert

[lightman]

If anything it will be easier to use. You will notice that its heavier. Like the others, I've never had a bad RCBS mold and I have several. But being steel it can rust so you will ned to protect it some way. I spray mine with whatever I use on my guns and then degrease it with brake cleaner before using it. Not that the steel sprue cutter on your Lees won't rust either.

[OS OK]

Over in N.C. & PA you have some heavy humidity to deal with so...if you are going to collect some iron, I suggest you slather them well, inside & out with some Mineral Oil USP, keep them mated with a strong rubber band and place these high quality moulds in a protective box.

https://i.imgur.com/iLANmFN.jpg

[Winger Ed.]

place these high quality moulds in a protective box.

I had one rust and ruin.
I got kind of mad and now long term store mine in a pint jar full of motor oil.

[OS OK]

I had one rust and ruin.
I got kind of mad and now long term store mine in a pint jar full of motor oil.

That's a shame, sorry to hear it.
Out here behind enemy lines I am blessed with an almost high desert climate so Mineral Oil USP just may be the wrong choice for the Coastal Salt Air like the Gulf Coast enjoys.

[justindad]

You can run them hotter and faster without problems (I have had lead stick to brass, aluminum, and iron after casting too fast - iron was by far the easiest to clean up; I had to melt beeswax on a heated aluminum mold). They come from the factory free from burrs (except Lyman), because lead will practically never break in a burr of iron. Lead between the block and sprue plate will not gall the iron. If a spot of lead sticks, you can scratch it off with a solidified sprue cut and not have to worry about marring the surface. You don’t have to be so careful tapping the mold handle hinge. Holds heat longer so you can pause to look at things without your mold cooling off so bad. Thermal expansion of aluminum is greater than iron, so greater dimensional stability as the boolits solidify (may not have a measure able effect). Iron can take more abuse before it deforms. Iron molds require less maintenance and cleaning - apply Remoil when you shut off the pot, and clean (optional) cavities only with alcohol on a a-tip when you turn the pot on. That’s been my experience, but I’m not the best nor the most careful person at this art. Can you tell I like iron (except new Lyman)?

[45DUDE]

Youll quickly find out how heavy it is compared to a Lee..........lot better made for sure .....you can take the handles off ,for one thing.........but then handles are extra cost item.........will it cast better bullets? ..IMHO....No!..........I might add,Lyman molds are now steel ,not cast iron,and the worst mold I have ever used was a new Lyman ......the bullets simply stuck to either half like glue.

I have some new Lyman molds and I think the sticking is because the lube grooves are square. The booiits will stick to one side and it bounced to the other when I whacked it and it stuck there also. I found it better to lay the mold flat on a piece of wood and whack flat. <I use a hammer handle>4 cavity's are the ones that give a little trouble dropping for me but I can live with it. Smoking a sticky mold with a candle helps a lot for me also. The LEE molds --most you can use out of the mold and can pan lube or powder coat without sizing is a +. Most Lyman molds drop oversize and need to be resized and lubed with a 450 or whatever which I like. I bench a lot and feel that sizing helps with accuracy. I have a couple of RCBS molds for .357 that drop good.

[john.k]

I must say ,my RCBS 45/300 simply drops bullets as the handles are opened .....cant say better than that ......however ,since I got arthritis and tendonitis in my hands ,it seems like casting with a 4lb hammer..........so i suppose I could say it was only good for 50 years .

[243winxb]

Easier to make better bullets then Lee. Storage- Molds get Breakfree CLP & placed in plastic bag. Kept in damp basement.

Next use, clean with hot tap water, dawn & stencil brush.

[OS OK]

Easier to make better bullets then Lee. Storage- Molds get Breakfree CLP & placed in plastic bag. Kept in damp basement.

Next use, clean with hot tap water, dawn & stencil brush.

https://i.imgur.com/RIs6AM5.jpg

I think pre & post-maintenance is a must with iron.
I think many treat them like a wrench...use it and throw it back on the bench and forget it till next time it's needed.

[gunther]

If you or a buddy has access to the brown, waxy, paper new bearings are wrapped in, wrap your iron molds in that, and store in a fairly air-tight container. That avoids 98% of the rust issues. As counter-intuitive as it sounds, Kroil will initially clean an iron mold, and act as a mold release, too.

[ascast]

I find them to get up and running very fast. Never had a new bad one, 2nd hand maybe. If not first place, then very close. I wish they made a wider variety, like Lee. Rust-I stick them in GI Ammo cans, no oil or nothing, same desiccant pouches and close them up. NEVER had any rust issues this way

[almar]

Youll quickly find out how heavy it is compared to a Lee..........lot better made for sure .....you can take the handles off ,for one thing.........but then handles are extra cost item.........will it cast better bullets? ..IMHO....No!..........I might add,Lyman molds are now steel ,not cast iron,and the worst mold I have ever used was a new Lyman ......the bullets simply stuck to either half like glue.

i once praised the lyman moulds in this forum some time ago but what i had (until recently) was very old ones. I recently bought a new one and i hate it, its basically not used, it throws out of round bullets at + AND minus the nominal so sizing wont fix it.

[45DUDE]

i once praised the lyman moulds in this forum some time ago but what i had (until recently) was very old ones. I recently bought a new one and i hate it, its basically not used, it throws out of round bullets at + AND minus the nominal so sizing wont fix it.

What caliber? If defective they will replace. Could you post a photo of the boolits and what size they drop? It could be the mix.

[justindad]

I had a defective Lyman mold, I sent it in for repair, it came back in worse shape. Lyman told me they would fix their mistake, but then never again responded to communication. You can send it in to Lyman if you will otherwise throw it in the trash can, but you may loose out entirely on your shipping costs and time to get to the USPS.
*
I will buy old, used Lyman molds. I will never again buy a new Lyman mold.

[jdgabbard]

I think you'll find that it is a night and day difference between Aluminum and Iron molds. At least molds of good quality and condition. With an iron mold you can just sit it on the rim of your pot while your bringing your melt up to temp. Usually after 3-4 castings you're at temp, and it'll start dropping beautiful bullets. With Iron I like to run hotter, and get a little bit of a frosty bullet. But the beauty of iron is that it just maintains a good temperature. Once you get it into the zone it just stays there. And if it does start to get too hot you can let it sit for just a minute and it'll be back in the zone. It is VERY consistent once you get into the right temperature zone.

Iron molds are less likely to warp, unlike many of the aluminum molds. One of the biggest issues people used to have with Lee molds, other than the holes being egg shaped, undersized, or poorly machined, or caused galling on the top of the mold, were it was fairly common to find warped molds. This is a result of a variety of problems, and as I hears is not quite as big of a problem as before - since they went to a new design with CNC cut molds. But with iron, as mentioned above, even the little issues are a breeze to resolve.

Iron molds if properly cared for will outlast your kids. I have plenty of old Ideal molds that are older than my grandfather - is long since passed. I haven't seen this type of durability in Lee molds. Though some of the other manufactures while last that long if really pampered. But there is no denying, iron is just more durable.

Honestly, I absolutely love iron molds. Even if they're problematic. They're just nicer in so many ways than aluminum molds. That said, brass molds hold a very close second in my opinion. While they exhibit a few more issues akin to aluminum molds, they are just super nice. Any more the iron molds I buy are usually older molds: Lyman/Ideal and H&G molds from many decades ago - preferably in 4-cav if I can find them. Anything new, I 10:1 prefer brass over aluminum. But that comes with buying from custom mold services such as MP, NOE, and Accurate.

But all in all, I think once you get some casting time under your belt with iron you won't look back to aluminum the same. It's just a better material for molds in my opinion. However, once you try a brass mold, you'll have a hard time picking one over the other.

Just my .02

[imashooter2]

I never understood oiling a mold once it is clean. Mine get stored in a dry box with desiccant and VCI paper.

[uscra112]

Yah, iron heats up slower, but holds heat better, which lets me slow down my casting rhythm a bit, as opposed to aluminum. Despite being heavier, I find iron to be less fatiguing, therefor.

VPI paper will protect a mould for a while, but not forever. Last summer I opened up one that had not been used since about 2009, and there was a light frosting of rust. The inhibitor chemical had all evaporated away. Not fatal, a light lapping with 800 grit restored it, but I won't count on VPI again unless I also seal the mould airtight, as in a Ziploc bag or something.

BTW the glass jars the Smuckers Natural PB comes in are perfect. I store my Ed's Red in them, because even acetone can't get past that seal.

[OS OK]

I didn't think of this till just now but...I used to store my welding rods in a large industrial size first aid kit with a 40 watt lamp in the bottom.
That kept the flux dry as a bone...betcha the same type enclosure would take care of iron moulds where the humidity is high.

[Shopdog]

If you were to start keeping notes on your individual moulds...... highly recommended.

You're going to see patterns in not only mould performance,but hopefully yours as well. In most instances, "iron" moulds will have a larger window of temperature and ease of use. The heat retention of iron over aluminum should smooth things out for the "you" side of the cast by not demanding constant monitoring. I like,and use aluminum... but to produce very tight QC,they make me work harder.

Now,if the particular mould(aluminum) is dimensionally correct for the application,of for whatever reason happens to produce a very round bullet....that extra work can be justified. Same as an iron mould "may" cast easier but it's not hitting the #'s required for the rig.... well,you get the idea.

It's just not as simple as aluminum sucks,iron great.

[Larry Gibson]

I never understood oiling a mold once it is clean. Mine get stored in a dry box with desiccant and VCI paper.

That's what I learned to do also. Someone also sold nice heavy duty plastic bags that sealed quite well (blue colored) made to store most Lyman/RCBS/etc. moulds with handles in. When I lived up in the Pacific Northwest and started using those, I never had to oil then clean any of those moulds again.

Down here in the desert humidity/rust isn't a problem. I have perhaps 50+ iron moulds and 40+ aluminum moulds having 1 through 6 cavities. Once they have been properly cleaned they have not been oiled again. Since I mostly bottom pour (Lyman Mag20) and use a mould guide weight is not a problem, even with the heavy 4 cavity Lyman moulds. When dipper pouring it is always with large bullet (300+ gr) single cavity moulds so the weight isn't a problem there either.

I've not really found much of any difference between iron or aluminum moulds as to casting. I've had 3 brass moulds over the last 15 years and all three gave difficult bullet release. I still have one brass mould but seldom use it.

I wonder if Lyman moulds aren't resourced out to China these days?

[imashooter2]

Yah, iron heats up slower, but holds heat better, which lets me slow down my casting rhythm a bit, as opposed to aluminum. Despite being heavier, I find iron to be less fatiguing, therefor.

VPI paper will protect a mould for a while, but not forever. Last summer I opened up one that had not been used since about 2009, and there was a light frosting of rust. The inhibitor chemical had all evaporated away. Not fatal, a light lapping with 800 grit restored it, but I won't count on VPI again unless I also seal the mould airtight, as in a Ziploc bag or something.

BTW the glass jars the Smuckers Natural PB comes in are perfect. I store my Ed's Red in them, because even acetone can't get past that seal.

Replace the paper every 2 years. But the paper is belt and suspenders because the molds are stored in a sealed box with desiccant as well as the paper.

[jsizemore]

I asked a fella that has a bunch of H&G molds what he did for his molds. He's very persnickety about his molds. He hoses them down with WD40 and wraps them in aluminum foil. I omit the foil and use a 40mm ammo can. I got some reclaimed desiccant packs in the can too. I live on the east coast like the fella that gave me the advice. So far, it's worked.

[BRatigan]

The best preservative I have used for nearly anything exposed to the elements and for long term storage is cosmoline. Spray it on and forget it for years, provided you also store the item in a container if it's a precision piece like a mold. Its carnauba wax in a carrier. Cleans off with mineral spirits, gasoline, kerosine, etc. Not real cheap but effective.

[Harter66]

My first not Lee mould was an RCBS 45-200 SWC . I discovered very quickly how nice the iron moulds are .

You will find that the iron moulds don't make you rush as much to keep them hot . You will actually have to slow your pace a little bit and may even have to occasionally pause to let it cool a little.
It "feels" like a "smoother" flow but it's really about more uniform heat flow .

You won't be "dipping the corner" to get them up to temp resting on the pot top while it comes to temp sprue plate down will get the job done and have keepers in 3-5 pours generally....... depending on the specifics .

Rust isn't a big deal in desert west like 80-90 miles south of Reno but it's a huge neverending struggle here in the green hell , 60 miles south of Ft Smith AR . So far VCI paper, the paper wheel bearings used to come wrapped in , is doing the job of keeping them rust free . Unfortunately I will run out of that paper one day and have to resort to some other means .

I have Lee , NEI , Mountain, MP , Rapine , Lyman, Cramer , Lachmiller, RCBS , Ideal , and NOE moulds in iron brass and aluminum. I forgot about the H&G ....... I cast from 50-1600 gr per pour . In 1,2,3,4,5,6&8 cavity moulds . I've moved away from the really tiny 22 cals in singles so an 80 gr 25 cal is it for single little bitties .

[justindad]

For me, iron molds take less work. I don’t have to worry about, or deal with, lead tinning (brass) or lead smears (aluminum) on the top of the block. I have found zero burrs on iron molds (unlike aluminum and brass), which is probably because iron burrs won’t wear in while casting lead. I apply a light coat of Remoil (at least twice a year) and remove it with alcohol on a q-tip.
*
If aluminum molds were the only option, I would quit casting.

[leadhead]

I had a friend who stored a lot of Jap gun parts in motor oil and after
a few years, went to use them and they were rusted beyond use.
Something in the oil didn't jive with the metal and it ruined the parts.
Something to think about.

[uscra112]

Betcha it was USED motor oil, in which the acid neutralizers were all used up, and there was moisture entrained in it. As a mechanic in my youth, I saw what failing to change oil before storing a vehicle can do.

[GooseGestapo]

I had one rust and ruin.
I got kind of mad and now long term store mine in a pint jar full of motor oil.

I doubt it’s ruined. Soak it in some motor oil then use a bronze brush to work down the rust
I’ve used ink pen/typing erasers to gently clean and burnish the insides of the cavities. Be gentle and take your time. I don’t store my molds with oil as it makes it necessary to “break in” every time I cast with it. The old trick is to leave the last bullet/s in the mold. I then place a silica gel packet in the mold box. I keep all the molds in a microwave cart I’ve repurposed to a mobile casting station. Many are in shoe box sized plastic containers to protect from our hot, humid climate.
I’ve several expensive when new, “ruined “ molds that I’ve cast thousands of quality bullets with.

[john.k]

GG is exactly right......leave the last bullet in the mold.......i got this advice 65 years ago,yet have hardly seen it since.

[longbow]

If I had to pick one mould material it would be cast iron. I love all my moulds and have aluminum, brass and cast iron moulds but I love my cast iron moulds just a little bit more!

I've never figured out what the fuss is about cleaning them after oiling for storage. I used to live in Vancouver so high humidity and I decided I would oil my moulds after use to avoid any chance of rust.

Also, as john.k above says, I was advised to leave the last boolit in the mould which I have done ever since... except, I remove it then oil the entire mould, then put that boolit back in the cavity (or cavities), close the mould tightly then put it in its box.

My reasoning is that the boolit keeps the oil in place so it can't run off.

Whatever, I have never had a mould rust in 55 years of casting.

Cleaning them up for casting isn't a problem, I normally just wipe them out with a rag or paper towel then pre-heat until the sprue plate lube just starts to smoke.

Different strokes but it works for me.

Longbow

[tja6435]

GG is exactly right......leave the last bullet in the mold.......i got this advice 65 years ago,yet have hardly seen it since.


I do this, but I live in the high desert with single digit humidity. Only oil I use is for the pins and sprue bolt/washer

[Randy Bohannon]

My very expensive iron moulds get a piece of paraffin wax melted onto every surface while the mould is still hot. Excess is shed leaving them hermitically sealed with a very thin coating of wax that burns off during pre heating.

[atr]

leave a casting in the mold and then wrap and store the mold in a cotton sock.

[nicholst55]

Rust isn't a big deal in desert west like 80-90 miles south of Reno but it's a huge never ending struggle here in the green hell , 60 miles south of Ft Smith AR . So far VCI paper, the paper wheel bearings used to come wrapped in , is doing the job of keeping them rust free . Unfortunately I will run out of that paper one day and have to resort to some other means .

You do realize that you can buy VCI paper, right?

https://www.google.com/search?q=buy+vci+paper&newwindow=1&source=hp&ei=3YO0ZK-jFKWjqtsP4PaR-AY&iflsig=AD69kcEAAAAAZLSR7THbBmwWDg1PNGzpcBroaWhmg4J _&ved=0ahUKEwjvheCIt5SAAxWlkWoFHWB7BG8Q4dUDCAw&uact=5&oq=buy+vci+paper&gs_lp=Egdnd3Mtd2l6Ig1idXkgdmNpIHBhcGVyMgYQABgWGB4y CBAAGIoFGIYDMggQABiKBRiGAzIIEAAYigUYhgNI6yFQAFj2HH AAeACQAQCYAWKgAaIIqgECMTO4AQPIAQD4AQHCAgsQLhiDARix AxiABMICERAuGIAEGLEDGIMBGMcBGNEDwgIFEAAYgATCAg4QLh iABBixAxjHARjRA8ICCxAAGIAEGLEDGIMBwgIREC4YgwEYxwEY sQMY0QMYgATCAggQABiABBixA8ICCxAuGIoFGLEDGIMBwgILEA AYgAQYsQMYyQPCAg4QLhiABBiSAxjHARivAcICCxAAGIoFGLED GIMBwgILEC4YgAQYxwEYrwHCAg4QABiABBixAxiDARjJA8ICCB AAGIAEGJIDwgIIEAAYFhgeGA_CAgsQABgWGB4Y8QQYCg&sclient=gws-wiz

[wilecoyote]

leave a casting in the mold and then wrap and store the mold in a cotton sock.

...I would prefer a lubed wool sock, if/when available...

[blackthorn]

Quote "You do realize that you can buy VCI paper, right?"

Thanks for the link. Just ordered a stack of 6"x6" pre-cut sheets. Do not know that I will ever need that many (1000 sheets) but I can share with my two boys. Does VCI paper lose its strength over time? If so would shrink-packing excess paper preserve it?

[brassrat]

I got a good deal on a huge bunch of paper and cut the rolls down to manageable sizes and wrapped them in stretch wrap. This was at least ten years ago.I keep a layer or three in a, big, airtight, box. A Pelican copy but not Harbor Freight.Perfect spot for my eight or so moulds. The rolls still have plenty of the VCI smell.

[uscra112]

Quote "You do realize that you can buy VCI paper, right?"

Thanks for the link. Just ordered a stack of 6"x6" pre-cut sheets. Do not know that I will ever need that many (1000 sheets) but I can share with my two boys. Does VCI paper lose its strength over time? If so would shrink-packing excess paper preserve it?

Yes, and yes. The paper slowly releases a rust-inhibiting vapor, (hence Vapor Phase Inhibitor) and eventually it is all gone. Storing vacuum-sealed would stop the vapor loss.

(LOL - I see it is now called vapor CORROSION inhibitor. Dinosaur that I am, I never knew of the change.) You can also buy it on Amazon.

[blackthorn]

Yes, and yes. The paper slowly releases a rust-inhibiting vapor, (hence Vapor Phase Inhibitor) and eventually it is all gone. Storing vacuum-sealed would stop the vapor loss.

(LOL - I see it is now called vapor CORROSION inhibitor. Dinosaur that I am, I never knew of the change.) You can also buy it on Amazon.

Thanks for the reply. Another question; any idea how long the paper is effective before it deteriorates in use?

[uscra112]

Thanks for the reply. Another question; any idea how long the paper is effective before it deteriorates in use?

It would certainly depend on storage conditions. I can tell you that a Lyman mould I wrapped up prior to my retirement in 2009 was noticeably rusted 10 years later, it having been simply placed back in its' plastic box, and left on a shelf. The paper was completely dry and almost white. An airtight enclosure would have been much better, I am sure.

I use another form of this chemical, which is supplied as 1"x2" "coupons", in gun cases. Its' mfgr. says 2 years.

More than that I cannot say.

[blackthorn]

Thanks again. I feel an experiment coming on, but I live in an area designated as semi-dessert so maybe I am being just a bit paranoid. None of my moulds show any signs of corrosion and they have been stored with just a light film of oil for years.

[john.k]

If you want things to rust ,simply expose them to a current of air ,ie a draught when there is a change of temperature ........early morning is a common time to see water /condensation forming ........here the common time is around 9am .......the sun hits the wet grass,all my stuff indoors is still cold from the nightime temp......big beads of water form on anything metal exposed to a draught ...........An interesting phenomenon is the salt desert in Chile ....old trucks are driven through pools of salty water ,yet there is no rust ...the relative humidity is 3%...........similar situation in underground salt caverns .

[Rapier]

If you cast with multiple moulds at one time the iron moulds permit a smooth casting process. They are slow to heat, but sitting the iron moulds with handles on the alloy when you turn the pour pot on makes the time work out. They also cool slowly which smooths the casting process out. I cast with four iron dual cavity moulds at a time, water drop through peanuts. I do very obvious different bullets, like 358-200, 30 cal-165, 44-240, 9mm-124 TC, so there is no problem sorting them out.

My casting process is all about maximizing uniformity of the bullets as produced. My need, for competition, is consistent fill out and bullet weight. I simply can not have rust.

Iron or raw steel requires care to prevent rust in high temperatures and high humidity, Bees wax on hot metal works well for me. I leave the last bullet in the mould, apply the wax when hot, then when cold, spray the handle joint and exterior of the mould with G-96. If you spray it hot, the cavities suck the oil in as they cool, causing a need to acetone the inside several times for later use.

I also use Frankfort Arsenal Drop Out on new, warm moulds, not hot, only warmed to dry with a propane tourch, after a through degreasing.

[jim 44-40]

You do realize that you can buy VCI paper, right?

https://www.google.com/search?q=buy+vci+paper&newwindow=1&source=hp&ei=3YO0ZK-jFKWjqtsP4PaR-AY&iflsig=AD69kcEAAAAAZLSR7THbBmwWDg1PNGzpcBroaWhmg4J _&ved=0ahUKEwjvheCIt5SAAxWlkWoFHWB7BG8Q4dUDCAw&uact=5&oq=buy+vci+paper&gs_lp=Egdnd3Mtd2l6Ig1idXkgdmNpIHBhcGVyMgYQABgWGB4y CBAAGIoFGIYDMggQABiKBRiGAzIIEAAYigUYhgNI6yFQAFj2HH AAeACQAQCYAWKgAaIIqgECMTO4AQPIAQD4AQHCAgsQLhiDARix AxiABMICERAuGIAEGLEDGIMBGMcBGNEDwgIFEAAYgATCAg4QLh iABBixAxjHARjRA8ICCxAAGIAEGLEDGIMBwgIREC4YgwEYxwEY sQMY0QMYgATCAggQABiABBixA8ICCxAuGIoFGLEDGIMBwgILEA AYgAQYsQMYyQPCAg4QLhiABBiSAxjHARivAcICCxAAGIoFGLED GIMBwgILEC4YgAQYxwEYrwHCAg4QABiABBixAxiDARjJA8ICCB AAGIAEGJIDwgIIEAAYFhgeGA_CAgsQABgWGB4Y8QQYCg&sclient=gws-wiz

Good stuff that VCI paper,been using it for molds for quite awhile.

[uscra112]

Hang a sheet or two in your gun safe.

[tazman]

I spray my steel molds with a light coating of Kroil when I am done with a casting session. It protects well and burns off with a couple of runs in the chambers.
No buildup has occurred in my molds from oil residue after decades of use.