ideal temp to operate an iron mould?

[glockfan]

since i'm new to bullet casting, some questions arise in my mind. this one being one of them ,and it looks like crucial to me .

i know that , when the mould isn't hot enough it gives frosted peas, while i'm not sure what is happening when the mold is too hot and how both extremes affect the boolits in performance-integrity.

what would be the best temp to operate a 4 cavities 9mm iron mold,and how do you keep track of the mould's temp ,or better, how do you keep your mould at the right temperature during a stopage in the casting session ?

i want to thanks those of you who are offering some valuable answers.

i'm not joking when i tell you guys that i'm learning the ropes of boolit casting through the infos i'm collecting over this very,very informative forum.

[ShooterAZ]

Each mold I own is a different animal. Your boolits will tell you if your mold/alloy is too hot OR too cold. I keep a log book for keeping track of this kind of stuff like what alloy was used and what the mold temp was. I generally start out at 725* with the pot temp and adjust casting cadence and/or pot temp from there. If you cast at a fast rate, your mold will get hotter and you may need to slow down a tad.

[Calamity Jake]

since i'm new to bullet casting, some questions arise in my mind. this one being one of them ,and it looks like crucial to me .

i know that , when the mould isn't hot enough it gives frosted peas, while i'm not sure what is happening when the mold is too hot and how both extremes affect the boolits in performance-integrity.

what would be the best temp to operate a 4 cavities 9mm iron mold,and how do you keep track of the mould's temp ,or better, how do you keep your mould at the right temperature during a stopage in the casting session ?

i want to thanks those of you who are offering some valuable answers.

i'm not joking when i tell you guys that i'm learning the ropes of boolit casting through the infos i'm collecting over this very,very informative forum.

A cold mold gives shinny/wrinkled boolits, a to hot mold gives the frosted boolits.
Use a hot plate with an old circular saw blade on the element to preheat your molds.
With melt temp around 700° cast boolit looking for good fillout.
Don't spend a lot of time looking at the boolit as this allows the mold to get cold.
It takes time to learn what each mold likes as far as temp in concerned.

[Mike W1]

Long as you asked about temperature of the mould. Have been doing some experimenting with just one particular mould, a Lyman DC. While the lead pots are getting up to temperature, about 20 minutes, the hot plate gets my mould around 256-270° F. Usually around -5 cast cycles will bring the mould into the 310-320° F range. BTW weighing those first 2 bullets they will generally be in the range of ± .5 grain of the average so obviously this mould doesn't have to get fully heated to cast well but I find it does release the bullets from the mould better at the higher range. But that's just one mould, they aren't all gonna be just like this one. With the particular alloy I'm using 689° F works just fine.

[JonB_in_Glencoe]

As ShooterAZ mentioned, each mold "is a different animal".

Factors involved with ideal mold temp.
>Type of metal the mold (and sprue plate) is made of and it's size (mass).
>number of cavities and size of cavities
>Alloy temp
>Rate of casting (how many pours/dumps per minute)
>Ambient air temp. as well as air flow in the casting area.
there maybe more?

Here's the secret for any new caster. Practice, practice, practice. The best way to get uniform boolits, is to cast (without stoppages) at the same rate of speed. Uniform, as in same good fillout and same amount of frost/shine, which ever you desire, that can be adjusted by casting rate, which is basically adjusting the mold temperature. I try to cast boolits that are just beyond the shiney state, with just a dull grey uniform finish to the entire boolit, but not a heavily frosted look.. It's as simple as this, uniform boolits are more accurate than non-uniform boolits.

So, the conclusion to your question, "what would be the best temp to operate a 4 cavities 9mm iron mold", only you can answer that.

[Baja_Traveler]

I use a fancy digital hot/stir plate I got as laboratory surplus. It's accurate, but it only displays in degrees Celsius. I've found that if I set it to 310* while the pot heats up, which equates to 572* F - I get perfect drops from the first bullet using both my 2 cavity iron, and my 5 cavity aluminum molds. I just have to watch the results as they drop - get in too much of a hurry and I start seeing frost showing up on the noses so I have to slow it down a bit to get the shine back.
I've read some will actually run the base of the mold over a wet rag to cool it down, but I have never done that - not because of the water around molten lead wives tale, but I don't want to chance warping. Having heat treated before, I've seen how supposedly large chunks of metal can move around doing that...

[gwpercle]

since i'm new to bullet casting, some questions arise in my mind. this one being one of them ,and it looks like crucial to me .

i know that , when the mould isn't hot enough it gives frosted peas, while i'm not sure what is happening when the mold is too hot and how both extremes affect the boolits in performance-integrity.

what would be the best temp to operate a 4 cavities 9mm iron mold,and how do you keep track of the mould's temp ,or better, how do you keep your mould at the right temperature during a stopage in the casting session ?

i want to thanks those of you who are offering some valuable answers.

i'm not joking when i tell you guys that i'm learning the ropes of boolit casting through the infos i'm collecting over this very,very informative forum.

Besides this site , pick up a Lyman Cast Bullet Handbook and study it . Lots of great basic info in it , answers to questions you haven't even thought about asking and proven load data to boot.
Load safe,
Gary

[country gent]

A lot of things come together to cast good bullets. Alloy temp, cadence, mould temp, ambient temp and air flow. Alloy temp is important as it will greatly affect mould temps. Hotter and mould temp rises cooler and moulds temp drops maybe below where it will cast its best. Cadence a fast cadence will raise the mouilds temp and a slower cadence will lower it. Ambient temp isn't as critical but does cool faster. A fan or breeze can suck a lot of heat away from a mould sitting out in the open.

Its a combination of these that makes it work. Alloy temp a fast cadence and shield from breezes your mould may start to cast frosted bullets after 20-50 casts, a slow cadence and no shielding and the mould may cool to producing wrinkles in 20-50 casts.

A lot preheat the mould one hot plate or on the lead pot before starting to cast. This helps a lot with getting good bullets in a very few pours. Another is to dip the mould in the alloy until lead dosnt stick to it. This may be on the warm side. Another is to have the mould warmed evenly from top to bottom and front to back.

There are temp probes that a set of blocks can be drilled to accept that will show temp when casting and the effects of alloy temps and cadence on this temp also.

[Walter Laich]

what to make sure you saw the comment:

VERY HOT MOLD CAUSE FROSTING

was mentioned in several answers but could have been missed.

[glockfan]

woaW. thanks for your answers guys. it's a lot to process for a rookie like me,but of course that is of a tremendous help .

here's what i retain


1-once i'll find the temp where the mold produce the nicest looking boolits,cadence is what will keep my mold at the ideal temp .

2- there's some '',device'' i can use to control the mold's temp like a fan, a wet rag...and i could even drill my bloc to use some probes ,so i'm getting a total control over the mold's temp

3-a pre-heat plate is very practical so i can up the mold temp ,and totally required to pre-heat the mold at the beggining of the casting session

4-between 650 and 700fh is where the molten lead should be at any time,and probably my mold will get me the best result at around 250-275 ,but each mold will gives its best boolit inside those numbers....

5-a cold mold will throw out wrinkles and a hot mold will get me frosted boolits....( i'm not sure if frosted boolits must be thrown back in the pot because accuracy might be very bad)

6-i realize now what i've dived into when i decided to cast my own boolits, so many factors to keep in check and to remember . it's somehow quite complex.

7-i now feel that i'm due for a donation...i'd like to be a part of this community , then one day i would be able to help a newbie like you guys did for me in this thread .

[Baja_Traveler]

Your number 4 - lower lead temps work for a lot of larger caliber moulds - but if you start casting the tiny stuff temps have to go up. When I cast 40 grainers for my 218 Bee the lead temp has to be at least 825* or I can't get proper fill out. Today I got a new NOE mold, and just now I was casting 85gr 25-20 boolits and the pot had to be 800* to hit the sweet spot.

[bangerjim]

Don't get hung up on monitoring mold temp and having at is at a precipice temp! Experience will get you there.

Just heat your mold to FULL casting temp ona hotplate B4 ever starting. I water drop all my boolits just to cool them and the "talk" to me......not sizzle and the melt is too cold. Sharp sizzle and it is too hot. You will lear the right sound.

And........every mold is different. Casting is 90% doing and 10% reading and "worrying" about temps. Just get out there, cast a bunch and learn what is right for each mold and what does not work.

And frosted booits are perfectly good!

Also....preheat all your feed ingots on your hotplate to speed up the heat cycle of your casting pot.

Good luck and happy casting. It is all in the expereince you gain. You can't cast from just reading about it.

[country gent]

Another little bit, some feel frosted bullets hold PC or the tumble lubes better than the shiny smooth bullets.

[lightman]

Like a few of the others have said, I agree about not getting too hung up on mold temp. I run my pot temp in the 720-730º range, pre-heat my mold and adjust my casting speed to get good bullets. Some of my molds require me to wait a few seconds after dumping the bullets and a few of them require me to cast as fast as possible. I never felt the need or desire to drill a mold for a temp probe, although some casters do.

[glockfan]

thanks all for your thoughtfull advices....i'm quite a cartesian type of personality. i always brainstorm and analyse things endlessly before acting ,or in this case, before diving into realty. not exactly practical i know...but i hate failing when i invest myself into something new. it is kind of a personal discouragement for me. i know, i should adopt a practical approach to casting because as some of you stated , casting good boolits is all about first hand experience with specific equipment .


i smelted 100lbs of ww ingots yesterday.it was very cold out there but i managed it in 5hours
using my second lee pro 4-20 ..i now have a little 170lbs stash ready for work. it is cold outside,so i'm gonna have to cast my first boolits indoor. i got some new 2097 3M filters for my 7503 half face mask,so i won't risk lead poisoning , which i've recently walked out of because too many indoor shooting lol.

i decided to start my casting endeavors with 9mm only,using a lyman 356637 flat nose . also i bought a lyman 4500 lubrisizer with 2 resizing dies .1 in 356 and 1 in 357 ; to make sure i'm covering all my nines since i'm looking for at least the same accuracy as with commercial jacketed bullets. i'm gonna coat my boolits with hi tek ,so i'm guessing resizing at 356 would be sufficient for acceptable accuracy and keeping my barrels clean.

then if i'm good at it i will order a 40S&W groovless accurate mold for my game guns.

[gunarea]

Hey glockfan
You are wise to seek experienced guidance. With no precision instrumentation, giving you specific temperatures would be less than helpful. Acceptable projectiles can be produced with practice and limited resources.

Consistency is the key! It is OK to screw up, just screw up the same every time. Horrible castings melt!

Removing heat from the casting mould is mandatory! Doing so with ambient air temp and reduced cadence is a relaxing method. An large empty coffee can acting as a heat sink speeds the process up. Your Lyman mould should not be introduced to water for cooling. An aluminum heat sink with integral fan does a very thorough convective heat removal. Mould cooling is most effective from the mould bottom rather than the top.

This seldom gets mention but is critical to a more consistent mould temp. When casting(especially larger gang moulds), alternate front to back with back to front filling. Although the physics and logic are obvious, application is surprisingly spotty throughout our experts.

When you get into more sophisticated temperature monitoring, more specific information will be of value to you.

213297

What you see is the pursuit of home cast competition quality projectiles by a successful anal competitive shooter. Dual probe Fluke thermometer to monitor heat sink and interior mould temps. Dual probe analytical PID with mid/low pot and spout control points. A quick change Emerson ETQC monitor using a ceramic magnet probe for mould exterior. Yeah, I am told constantly what I do is over the top and wasted resources. Mostly by those who don't compete or do not come in second or third to me. Feel free to accept or reject any and all of my advice and procedures. For any further help I'm here.
Roy

[mozeppa]

Another little bit, some feel frosted bullets hold PC or the tumble lubes better than the shiny smooth bullets.

pc bonds at a molecular level to the metals surface ...shiney or frosty.

[glockfan]

@gunarea....an infinite thank to you for the super good advices and your bench pictures .

your approach of casting is exactly how i'd like to end up myself ; i've had the good idea of ordering the lyman digital lead thermometer so i can take notes on what temp my lead gives me the best boolits. would like to do the same with my lyman mold ; i mean....i know it may look over the top, point is being able to take note of what works best, is somehow securizing for me ; afterward, it's done. no more guess working; a matter of doing my work with peace of mind.

the idea of casting my own germinated when i've learned that my wife wanted to comptete in uspsa and ipsc too....so now, i have 2 guns to feed,and there's no way i have the funds to use commercial jacketed anymore. on the other hand, i want my boolits as inherently precise as the zero's i was using . i now know this is a gigantic task of research and trial of errors haha ; while i strongly believes that with such cartesian approach as yours, i could
eventually get there with minimal troubles haha ...and when i say mistake free,i mean not having to remelt a messed batch of hundreds of boolits haha. i'm semi retired, and i feel i don't have enough time to afford messing a batch of boolits. that's the why i need to cumulate the greatest amount of infos BEFORE actually starting to really cast in large batch.

[gunarea]

Hey glockfan
With cost as a secondary concern. Take your thermometer funds as part of the cost of a PID for your casting pot. The PID will show pot temperature and keep it much more consistent. Stable pot temps is the first step towards repeatable product. From this step, the other variables become much more controllable.

Heat removal management can be a very inexpensive item. As stated, slow cadence and ambient air cooling can be relaxing but it does cut down production.

213312 213313

The little square thing, under the Fluke instrument just left of the Lee casting pot, is a computer power supply heat sink with integral cooling fan. These can be gotten very inexpensively at a scrap recycler or relatively inexpensive at a computer repair shop. With just minimal practice you can cool the mould quickly to eject castings and maintain optimal empty mould temp.

213315

The cover on my pot is a metal spatula that helps speed up pot melt and replenish time. It also serves as a warm up spot for the mould being used. Very cheap!

On a personal note, my wife, Debbie also shoots competitively. Although the matches are a good time, I treasure our practice time together. She has beat me on occasion at some local and regional tournaments. Debbie has a few Florida State bronze medals. Even more noteworthy is she does not compete in the women classes and we both compete exclusively using our home loaded ammo using our home cast projectiles. We are also in our sixties, so I simply buy 9mm brass rather than bend over.

So jump in, many others have succeeded with much less help and support.
Roy