Proper casting tempreature for WW

[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.

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 . . .

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!!

[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 . . .

Rick

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

Gear

[cbrick]

Sorry, just couldn't resist, I tried to resist but found that resitance was futile.

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.