For the Iron Mold casters

[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+...client=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?