How do you measure your mold temperature?

[Wm Cook]

How do you measure the temperature of your mold? I would like to find something that would allow me to scan surface temperature with iron, aluminum and brass multiple cavity molds top, bottom, front and back. Just to see what’s going on.

Not sure if an electronic meat thermometer would work just holding the pointy end to the mold. Thanks.

[dh2]

I go up with the heat until it turns out good looking bullets.

[Rcmaveric]

If it starts smoking its too hot.

Sent from my SM-N970U using Tapatalk

[dtknowles]

I don't measure the temperature of my mold but I do watch to see how fast the sprue hardens.

Tim

[fcvan]

I measure temp by watching the sprue cool/solidify, 10 to 15 seconds. When I'm speed casting I blow on the sprue to cool it faster. Most of the time I cast with 2 molds and get into a rhythm. I cast for 30 years without a thermometer. A few years back, I got a Lyman and all it did was confirm I was at 715 - 720 degrees. I put the thermometer back in the box, I still go by eye on the melt. I generally pour with 2 cavity molds, pouring both cavities at the same time with a big sprue, it helps keep the sprue plate at temp.

[monadnock#5]

I've never used one while casting, but there are infrared thermometers available. I think Harbor Freight carries them. It might be good for checking the temp while preheating on the hotplate, but once you start casting, don't stop to do anything else.

[TjB101]

I’ll dip the corner of my mold into the pot for a few minutes ... when lead stops sticking to the mold I’m ready to start.

[DAVIDMAGNUM]

There are three temperatures that I observe with my aluminum molds. Shiny bullets that are wrinkled = COLD.
Frosted bullets and/or bullets that fracture when dropped = HOT
Perfect bullets that fall out easily = JUST RIGHT

[gunarea]

274721
We are in an arena where "good enough" rules the majority. My temp monitoring is far and beyond average. For best and most consistent results, a hole needs to be in the mould for a probe. Outside readings are subject to even the most slight deviations. Ambient conditions introduce variables to only allow for averages to be held. Only high level competition and OCD dictates such precise projectiles be produced. The cost of such equipment and effort expended, is not a fair trade for ammunition to be scattered about. It is possible to monitor and maintain precise consistent temps. Is it necessary? This is opinion area. My $.02.
Roy

[kenton]

For occasional use you could probably use a temp crayon used for welding preheat. You would probably want to clean it off each time though. The problem with infrared thermometers is they tend to get inaccurate reading on small objects and polished objects.

Something like this:
https://rrtools.com/product/templistik-500-degree/?attribute_degree=450&utm_source=Google%20Shopping&utm_campaign=Copy%20Copy%20GS_main&utm_medium=cpc&utm_term=4153&gclid=CjwKCAiAudD_BRBXEiwAudakX81wJYaT5qkwDan84ZaH 5I9iCOLMQOIj8gw7_2j84zxmCk_QYfyLuBoC3qMQAvD_BwE

[robg]

when there is no wrinkling after a couple of minutes im happy .if it takes ages for the sprues to harden i slow down or use another mold so i dont have to slow down.

[JonB_in_Glencoe]

Most don't need to know precise temp of mold, just watch the time it takes for Sprue to solidify and/also the color of the boolits.
BUT, if you feel the need to know precise temp, drill a hole for a temp probe. NOE offers that on new molds purchased from him.

[45-70 Chevroner]

Under normal casting conditions 700 to 800 degrees and using a cadence your mold will never get to the same temp as the lead in your pot. I think that you are getting into a gray area that will drive you nuts, mainly because the temperature of the mold is determined by the cadence of casting. I think most of us use two molds and cast as fast as we can to keep up a cadence and by doing that the two molds will stay at a proper temp for casting.

[Wm Cook]

I apologize for the rookie question I asked that started this thread but I have a lot to learn.

I think you're right when you say that individual needs and expectations vary. Most of the above reply's will meet the vast majority of casters needs. If frosting you slow down the pace and/or lower temperature of the melt, wrinkles speed and/or raise temperature. Acceptable quality of a cast bullet is in the eyes of the caster, nothing more, nothing less.

Unfortunately I do not have the God given talent for casting that most of you have so I have to fall back on my notes. If a mold hasn't been used in a while I need a cheat sheet tucked in with the mold telling me the last melt temperature, mold temperature/speed of cadence, rate of flow (quick dump, medium dump), off set pour or straight down the stack. The only way I had to measure mold temperature in the past was with an IR gun and the surface refraction is terrible unless you are measuring a spot on the mold painted jet black.

This question came about because I've cast using four new (to me) different molds these past few weeks. Three were MP brass (two hollow point and one round nose) and one was an aluminum Lee 6 cavity C312-155. One 22 cal, one 9mm and two 7.62 cal. All are small caliber running from 40 to 140 grain. What appeared to be the best target melt temperature between the four molds varied from 700 to 770 degrees. And as most would guess, the best drops came from running fast and consistent while watching the appearance of the drops.

Most believe the mold temperature is the key and the temperature of the mold is based on the cadence of the casting. So it may be true that there's more flexibility with melt temperature and that it's more important to keep the cadence consistence with the quality of the drops.

For the experienced caster recording temperatures is just plain crazy talk. They just heat up the pot and instinctively start casting. After 5 to 10 drops they are off and running. I envy such skill and the following is not required for 99% of the people who read this. If the quality of drops you're making is good enough for you, just keep on doing what your doing and you don't remind me how much time I'm wasting. Be kind and understand I'm sensitive and still learning.

The probe in the NOE mold is a good idea and in one search I found another who modified their molds to allow a plug in K type thermocouple. Since I'm curious about mold temperature top to bottom and front to back I want to be able to measure a couple different points on the mold every 20 to 40 drops. The time to check mold temperature will probable be less than the time it takes for the sprue to frost up. And this isn't meant to be a long term every casting event practice. I just want to learn what happens to the mold temperature from the time it leaves the hot plate to where it is dropping bullets to my level of expectations with that particular mold.

I better strap on my flak vest. There will be a ton of feedback like "you're wasting time and money, don't stop to twiddle around just keep pouring etc." Again, I ain't no expert and I like learning.

Below is what I decided to use. If anyone has any experience with probe use on the NOE molds I'd like to hear what you've learned.

274767

[whisler]

That looks like a contact thermometer similar to mine. I haven't used it to measure mold temp. but it should work. Good luck

[LabGuy]

I don’t measure mold temperature, yet. As a retired analytical chemist, I love measuring stuff.

[gunarea]

Hello Wm Cook
I completely understand both, curiosity and OCD. As seen in the photo of my dedicated casting area, it is taken seriously. Do not sell yourself short, practice makes perfect. Hands on repetition, will improve proficiency. Keeping notes as you mention, also goes a long way in consistency. Now for the monkey wrench thrown into your process. Moulds with more than a single cavity take on characteristics which must be addressed. Casting in a single repeated direction, will cause a "cooler" and respectfully "hotter" section of the multi cavity mould. Even in a trued and tuned mould, different temperatures produce different weights. Weight differences will open group size. For moulds with cavities of three and greater, center cavities always have a temp difference to outside cavities. Introduction of controlled temp alloy into less controlled and less consistent cavity temp will make for weight variations. A search will give many threads you might glean useful information from.

Now I will feed your curiosity and OCD. Cooling the mould to a consistent receiving temp is yet another path seldom followed. It is another critical component to precision projectiles. For what ever reason you may have for pursuing this quest, chasing perfection, I will be glad to assist you. Being the "lucky" guy at matches is fun.

There will be those who take the time to belittle any efforts to achieve such high standards. I say, if you enjoy this part of the hobby, go for it! Some of us will appreciate any new improvements you may discover and pass along. This rabbit hole is deep with a lot of turns. My post count is low, so I suppose my input has less credence.
Roy

[charlie b]

^^those are the key points on mold temps.

Post count means little. Shots in the X ring means a lot :)

If I could find a way to show temp on the mold without a wire hanging off...... Problem is cost of such a thing is a bit much :) Surface temps are not very useful.

I use a hot plate to warm the mold and keep it warm during breaks.

Experiment with different techniques and 'timing' to get the mold where you want it. Sometimes small changes make a difference. I can tell during a casting session when a bullet will be a bit 'off'. I lose the tempo, sprue puddle isn't big enough, etc.

For pistol bullets not used in bullseye competition this doesn't matter much. As long as the base of the bullet is mostly square at the edges, it will shoot fine. When you get to needing more precision, then the details can bite.

[bangerjim]

I listen to the "sizzle" of the drops in the cooling water pan I use. No fancy digital stuff here at all, even though I sell it all to customer for industrial temp control. Something this simple does not require microprocessor-based temp measurement or control......just plain old common sense and experience.

Experience is my thermometer!!!!!! If I did want to measure temp of molds I would make the end black chemically and shoot it with at IR gun. IR guns do NOT read shiny surfaces, like Al or brass molds, so you need to make a flat black surface on the end to get accurate temp reads.

And an electric hotplate to pre-heat all molds to about full casting temp makes all the difference. Perfect drops the 1st time.


banger :guntootsmiley:

[JonB_in_Glencoe]

SNIP...

Below is what I decided to use. If anyone has any experience with probe use on the NOE molds I'd like to hear what you've learned.

274767
Let us know how that works for you.
If I were to guess, a temp reading from the surface will not give you as good of information as internal temp, as with a Hole drilled for a Probe. I would guess surface temp will vary with ambient air temp and air circulation.

[GregLaROCHE]

There are a number of variables involved in casting a perfect boolit. Mold temperature is but one. Practice may be one of the most important factors. If a good boolit is what you’re after and not just curious about the mold’s temperature, you should get a solid type hot plate to set your mold on to get it up to and keep it at a good working temperature. The temperature of the large black surface of a hot plate can be verified with a thermometer a lot easier than a mold can. If your mold is getting too hot from casting, your boolits will start to get a frosty appearance. Then you know you have to let the mold cool down. Just keep practicing. Most people get the hang of it before long. If you seem to have a particular problem, you can always ask about it here.