Proper casting tempreature for WW

[peterso]

What is the best tempreature for casting bullets with WW?
Thanks,
Owen

[fryboy]

hi owen

in truth that depends upon what's in the ww alloy ...a lil more tin and it takes less heat a lil less tin and more antimony and it takes a bit more , for me it's usually between 700 and 750 and then i have this one problem mold that seems to prefer it a lil hotter .....[shrugz]

[lwknight]

You will get every answer under the sun on that question.
I rarely cast over 650-675 but , there are those who think you should cast at 850 degrees.
Just do what you gotta do. The hotter the pot , the harder it is to keep the molds cool enough to set up in a productive time.

[cbrick]

I cast WW at 700 degrees. What is needed is the mold temp up, not the alloy temp. Much higher than this the faster the metals in your alloy will oxidize beginning with your tin.

L W is right, there are those that will tell you that it's a shame that their pot won't get hotter, it only goes to 900 degrees. To each their own I guess.

Pre-heat your mold to a good casting temp, this should be somewhere around 400-450 depending on the mold. An alloy (pot) temp of 700 will easily keep your mold at 450 or even hotter. After pre-heating the mold regulate it's temp with casting rate. Think mold temp and save your tin.

Rick

[geargnasher]

What is the best tempreature for casting bullets with WW?
Thanks,
Owen

Owen, this is one of the best questions I've seen asked here in a while, and an important one I think.

Rick pretty much covered it, and the most I can do is reiterate and expound.

Keep in mind that keeping the mould at ideal casting temp (whatever that is for a given mould, it can vary greatly) is the most important thing temperature-wise in casting. This is often overlooked, and folks who cast at a pace too slow for the mould or don't preheat their moulds somehow unwittingly compensate by turning up the alloy heat, and perpetuate the "Crank the Heat" myth. Overheating the alloy has it's own set of issues, for example tin becomes ineffective as an oxidation barrier and viscosity modifier above 750*. If you're casting with straight wheel weights with (presumably) very low tin concentration, you can run a bit hotter, but as a rule you should focus on keeping the mould hot and the alloy as cool as will reasonably cast.

How hot is hot enough for the mould? A general rule for most of my moulds is about 5-6 seconds for the sprue puddle to set, and then still cut it with the flick of a gloved finger on two-cavity moulds. This is in the "light frost" range, which is what I generally try to achieve. Opinions vary on frost, some like a little and some think it's the devil, it's mostly personal preference.

Another rule of thumb on temp, the more tin you add (up to 2% content, you shouldn't ever need more) the lower the melt temp of the alloy, and thus the lower your pot temp needs to be. Lyman recommends 100* over liquidus temp, but as another member pointed out recently in another thread it's hard to tell when all the antimony has melted completely. Your alloy may be at full liquidus at 520* in theory, but you might get best casting results at 680* and a mould at 420*.

In the end, every casting session is different, and to achieve best results you need to know a little about the physics of what you're doing and the things you can adjust so as to be able to "roll with the punches" as weather, alloy, mould conditions, and the phase of the moon :D change, rather than just remember "700* with WW alloy*, because it won't always cast best at 700*.

Hope this helps,

Gear

[fredj338]

Depends some on the molds you use, but I seem to have good results just over 700deg, under 750deg.

[btroj]

Don't ask me, I cast everything at the same temp. My pots dial has not moved in years. A lot of years.
Somehow, I still get good results. My father in law casts everything full on hot. Pot is set to high, again it is for all alloys.
I do not have a thermometer, do not plan to get one. I will just keep on looking at results, and I am getting bullets I am happy with.

Don't over think it. Just my opinion.

Brad

[zuke]

Above 750. My LEE nozzle freeze's up under that temp.

[cbrick]

Above 750. My LEE nozzle freeze's up under that temp.

Then there is something wrong with your Lee pot temp control or your thermometer or something because 750 degree alloy will not freeze up your nozzle, could not. Your 130 over the liquidus temp of even pure lead, add any tin and your even further over the liquidus temp.

Rick

[lwknight]

Above 750. My LEE nozzle freeze's up under that temp.

Only if you have a fan blowing on it if you truely have it at 750 degrees.
BTDT, I learned to keep the fan on me and not the pot.

[geargnasher]

Zink contamination or trash clogging the nozzle will shut it off at 750*.

But I have to agree, something's probably off. When you hear hoofbeats, think horses, not zebras.

Gear

[sqlbullet]

Keep in mind that the composition of your mold will impact this as well. A mold that is more effecient at conducting heat away from the lead into the air will require a hotter pot to maintain temp. In general Aluminum molds will require a slightly hotter pot than steel, cast or brass molds.

I run Lee and Mountain Molds in Aluminum. And I run my pot at 700°.

[justingrosche]

Now here is the tricky part, once you've achieved your magic temperature, it changes. As your casting your pot level is decreasing, the remaining alloy is getting hotter. You can turn down the temp as you go but this will only work for so long. Right? You'll eventually run out of alloy.
So you add more ingots and sprues. Then raise the heat up, but whats the the temp now? Is it you optimum temperature? Probably not.
Dont sweat the small stuff, keep casting. I have a couple thermometers, that I haven't used in quite some time. Cadence in casting will get you through. Hot enough to fill and cold enough not to frost, and keep casting.
Justin

[shdwlkr]

In truth I don't know if I have ever paid attention to temp except for the way to hot side of the issue.
I have a Lee pot and set the temp dial where I have a good liquid lead and in my molds that I get a good bullet. Beyond that I don't have a clue what the temp is and really don't care as others have said the temp today will most likely be the temp the next time I cast so why even think about it.
I look for nice well filled bullets and being able to have a fairly good rhythm when casting so I know that the mold isn't too hot as I can cast until the pot needs to be refilled and then I get a break for 20-30 minutes while the new batch comes up to temp.

[cbrick]

Keep in mind that the composition of your mold will impact this as well. A mold that is more effecient at conducting heat away from the lead into the air will require a hotter pot to maintain temp. In general Aluminum molds will require a slightly hotter pot than steel, cast or brass molds.

I run Lee and Mountain Molds in Aluminum. And I run my pot at 700°.

Interesting. Conflicting but interesting.

Your right to run your pot at 700 degrees but a higher pot temp isn't needed to keep your molds at proper casting temp with iron, brass or aluminum. 700 degree alloy can easily keep any mold hot enough or even too hot.

As an example, your mold casts well at 450 degrees regardless of what it's made of. At 700 degrees your pot temp is 250 degrees over this proper mold temp and 250 degrees higher than proper mold temp will keep your mold at proper temp easily. No need whatsoever for a higher pot temp to maintain proper mold temp.

If your pot temp is 700 degrees and your bullets aren't forming well due to not enough heat it is not the fault of the 700 degree pot temp. It is a too cool mold, pre-heat the mold or cast faster to get the mold temp up, 700 degrees is plenty hot enough to do this.

Rick

[lwknight]

I use the lowest temperature that will work for large boolits because I have to go slower than my stride to keep the molds cool enough anyway.
In contrast my 125 grain Lee 6 banger makes me run like a banchie just to keep the mold hot and in that case getting the pot over 700 causes the spru plate to overheat to where by the time the spru is solid , the slower cadence lets the mold cool too much.

Its all a balancing act. Like several have said , " You just gotta find that sweet spot " .

[GRid.1569]

I sometimes wonder if my 750 degs is the same as your 750 degs....

or rather... how accurate is the calibration of the individual thermometers?

If an indicated temp is doin' good for you, stick to it. never mind everybody else...

For me it seems to be circa 750 - 800 on my Lyman thermo (LEE 20 lb'er & Lee moulds.....)

but as they say, "Your mileage may vary"

[lwknight]

I use the melting and slushy point of pure lead as a reference.
My casting thermometer reads 20 degrees higher than my PID which shows 620 degrees when pure lead is totally liquid and 605 when the lead is shushing up thick.
It appears that the PID is spot on.

[peterso]

This has given me a lot to think about. It would seem that one of the spot surface thermomoters would work well for monitoring the temp of your mold, just point and shoot so to speak. I have been scanning the net for a thermostat and probe that would work for my lead pot. I would like to find one that would have a probe small enough to drop right into my lead pot so that the thermostat would turn the pot on and off to maintain the tempreature as the lead goes down. I realize that I can just dial down the reostat on the Lee pot but it would sure be nice to have that part of the process automated at least to a point. Once the sweet spot is found and documented for each mold it would be nice to keep it going for a while.
If I find a suitable affordable thermostat I'll post the information.
Thanks for all the help,
Owen

[lwknight]

You can get a PID controller from Auber instruments for $44.00 and a thermocouple that can be submerged into the lead for $13.95. Even if you don't use the controller functions , its a cheap enough digital thermometer.

[cbrick]

I would like to find one that would have a probe small enough to drop right into my lead pot so that the thermostat would turn the pot on and off to maintain the tempreature as the lead goes down. I realize that I can just dial down the reostat on the Lee pot but it would sure be nice to have that part of the process automated at least to a point. Thanks for all the help, Owen

Like this? This one is from Magma so is pricier but does just what your looking for. With this set up the probe isn't inside the pot, there is a nut welded center bottom on the outside of the pot, the sensor attaches to this nut with a bolt.

The up-down arrows set the desired temp (red numbers) and the actual pot temp is displayed with the green numbers. When the set temp is reached the heating element turns off, when the temp lowers back to the set temp it turns back on.

For comparison, all three of my mechanical thermometers normally stay within about 15 degrees of the digital temp.

Rick

[geargnasher]

It's astonishing to me how many people have been casting for many, many years and never snap to the fact that mould temp is everything. The only criteria for pot temperature are determined by the specific needs of the alloy itself, NOT the mould's needs.

Mould temperature is reached by preheating (either external heat source like a hot plate or dipping in the pot lead, or by casting a bunch of culls really fast until it comes up to temperature), and maintained by casting rhythm.

Bottom line with most casting alloys that contain some tin is keep it under 750* due to negating the good effects of tin and creating excessive oxidation rates, and the alloy should be enough above full liquidus to flow well, usually IME 150-200 degrees or so above melt point and at least 100 above liquidus.

If you have an aluminum or brass mould that has a high thermal conductivity, especially large-caliber moulds which have lower mass than equivalent moulds of smaller caliber, the solution to keeping them hot enough to cast well is to HURRY UP, not TURN IT UP.

If your sprue plate is disproportionate to the blocks, and the blocks lose heat faster than the plate, cast fast enough to keep the blocks at a happy temperature and invert the mould and quench the sprue plate on a towel briefly after the pour like Bruce B. and Goatlips have demonstrated. If the opposite is true, pour a bigger sprue puddle to impart more heat to the sprue plate.

Running a casting session is just like driving a car through town, a constant state of observation and correction. You just have to pay attention to what the boolits are telling you and know what things you need to adjust for correction, while keeping basic information like oxidation threshold of tin (speed limit and stopping distance, keeping with the driving analogy) as basic rules of function.

Gear

[cbrick]

Yep Gear, seems I read something like that in post number 15 of this thread. :mrgreen:

Rick

[geargnasher]

Well, you know we're the "quoir". Bret too. I keep waiting for his version of "mould temp is more important than casting temp, keep it at 700, tin 2% or less......."

Gear

[cbrick]

Well, you know we're the "quoir". Gear

Yep, and maybe the choir too . . . :mrgreen:

Rick

[justingrosche]

It's astonishing to me how many people have been casting for many, many years and never snap to the fact that mould temp is everything. The only criteria for pot temperature are determined by the specific needs of the alloy itself, NOT the mould's needs.

Mould temperature is reached by preheating (either external heat source like a hot plate or dipping in the pot lead, or by casting a bunch of culls really fast until it comes up to temperature), and maintained by casting rhythm.

Bottom line with most casting alloys that contain some tin is keep it under 750* due to negating the good effects of tin and creating excessive oxidation rates, and the alloy should be enough above full liquidus to flow well, usually IME 150-200 degrees or so above melt point and at least 100 above liquidus.

If you have an aluminum or brass mould that has a high thermal conductivity, especially large-caliber moulds which have lower mass than equivalent moulds of smaller caliber, the solution to keeping them hot enough to cast well is to HURRY UP, not TURN IT UP.

If your sprue plate is disproportionate to the blocks, and the blocks lose heat faster than the plate, cast fast enough to keep the blocks at a happy temperature and invert the mould and quench the sprue plate on a towel briefly after the pour like Bruce B. and Goatlips have demonstrated. If the opposite is true, pour a bigger sprue puddle to impart more heat to the sprue plate.

Running a casting session is just like driving a car through town, a constant state of observation and correction. You just have to pay attention to what the boolits are telling you and know what things you need to adjust for correction, while keeping basic information like oxidation threshold of tin (speed limit and stopping distance, keeping with the driving analogy) as basic rules of function.

Gear

Well stated Gear!!:grin:

[starreloader]

Gear you are correct.. "Running a casting session is just like driving a car through town, a constant state of correction. You just pay attention to what the boolits are telling you and know what things you need to adjust for correction"

I don't think in over 35 years of casting have I ever needed to cast with a pot temperature much over 700 degrees.. It doesn't matter whether I am using aluminum or iron moulds, good casting always has to do with maintaing the temperature of the moulds and your casting technique.. I ladle cast using a 125 lb electric pot and always cast with (2) two 6, 8 or 10 cavity gang moulds.. I can drop quite a few very good boolits in an hour..

[101VooDoo]

I ladle cast using a 125 lb electric pot and always cast with (2) two 6, 8 or 10 cavity gang moulds.

Man, that is some serious dipping!

Jim

[geargnasher]

Yep, and maybe the choir too . . . :mrgreen:

Rick

That was pitiful attempt, wasn't it? :killingpc Dadgum French words.......

Gear

[cbrick]

http://www.lasc.us/smiley4.gif Sorry, just couldn't resist, I tried to resist but found that resitance was futile. http://www.lasc.us/smiley4.gif

Rick

[peterso]

I agree that you have to be observant when casting and respond if required. With a good set up it would be like driving through town on a limited access highway with no distractions from side roads or pedestrians only keeping centered in the lane and up to speed. I believe in working smarter not harder. If you can find the best pot tempreture and have it maintained for you and the best mold temp and maintain it then you cast many fewer culls and waste less time. Your results are more consistant and repeateable from session to session and quality production is obtained and maintained.
I use a combination of steel and aluminum molds to make boolits ranging from .22 for the hornet to .58 minie balls.
I believe that with in reason you should be able to find a pot temp that with consitent casting procedure will maintain proper mold temp for any given mold
The gentelman with the ultra large pot has an advantage over those of us with 10 or in my case 20 pound pots. When his pot reaches his desired temp it will stay there longer simply because of the mass. My pot has to be constantly fiddled with to maintain proper temp. I only get about 1/4 of the pot or 5 pounds at a constent temp. If I can maintain production temp for twice that long that will allow me to produce quality bullets to a natural resting point for my hands and arms and in summer thirst while the new metal comes up to temp. At 60 plus comfort seems to be more important than marthon production.

Owen

[mold maker]

Funny how much more important, comfort becomes, after youth has left.
I sit to cast, with 2 pots. A 10 lb bottom pour is above the BP pot I pour with. The upper gets a cold ingot and the sprues to preheat and refill the lower. As the pouring pot level drops I reach up and drop replacement melt from the upper pot. Casting time per 1000 with large cal 6 gang molds is much improved when you don't have to wait for the casting pot to reheat.
Being comfortable allows you to cast longer before a break to inspect the results.

[shdwlkr]

Cbrick
What I notice is that the outside temperature has more to do with my pot temp than anything else I do.
I do my casting when I get the time outside in my garage and if it is cooler in the garage it requires me to turn up the heat on my pot to get good bullets. As to what the temperature is I don't have a clue go more by the looks of my bullets than anything else and if they are coming out looking good then I feel that day I have the right temperature to cast. Another day it is all at the beginning again.

[Cowboy T]

I've now cast in aluminum, steel, and brass moulds. The mould's composition matters. The 650 deg. F. temperature works well for steel ones. However, on average, my Lee aluminum 6-cavity moulds prefer 700-750, and I have one whose sweet spot is 800 deg. Fortunately, with the aluminum moulds, you can use the trick of a wet sponge to periodically cool down the mould and sprue plate, and I can cast boatloads of boolits in short order with them.

Try out different temperatures, and if you need to, write down each mould's favoured temperature on a sheet of paper. It shouldn't take you long to figure out the sweet spots.