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 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.