Heat Difference: Pure Lead vs. Alloyed Lead?

[kcofohio]

I'm new to the casting scene. I have cleaned and recleaned a little over 100 lbs. of pure lead. Using a Lee Magnum Melter, with the switch at about 7 on the dial, from time to time, I was getting the bluish hue to the lead as I poured ingots. Now as I added Superhard and tin, making it 95-3-2 alloyed, I get a frosty look to the ingots. And before I can add more lead to the pot, a goldish film develops on the surface in the pot. I assume I need more heat if I get frosting. But the gold film throws me. I'm pouring ingots into a muffin tray.

I ordered two molds from MidwayUSA last week. I'm hoping to get them later this week. I'm feeling like a kid right before Christmas.

[Pipefitter]

Pure lead melts at a higher temperature than alloy lead. The colors in pure lead are really nothing to worry about. "Frosting" in your ingots is also not much to worry about, frosting in your finished cast boolits indicates a mold that is too hot, or your melt is too hot.
When casting pure lead for muzzleloading round balls or minnies the pot temperature needs to be somewhere around 700*-750*, when casting alloy for center fire boolits the temperature will be lower. You need to find the sweet spot somewhere between wrinkled boolits and frosted boolits for the mold you are using and the cadence of your casting.

[kcofohio]

Okay, thanks! Somehow I got it backwards. I thought frosting was from being too cool. I know I have lots to learn. Back to reading!

[Conditor22]

Lyman cast bullet #4 and http://www.lasc.us/ have a ton of great information

[kcofohio]

I like that web site. I should consider Lyman's casting manual. There is so much here on this site, it's hard to take it all in.

[JonB_in_Glencoe]

while many do cast without a thermometer (or PID), it really helps knowing the temperature of the melt, because the Dial on the Lee melter is not consistent with anything. Also, because of the placement of the thermostat and heating element on the Lee pot, the temperature of the alloy will increase as the alloy level goes down...this happens when keeping the dial in the same position. So many people will turn the dial down a tiny bit as the level goes down, to maintain a constant temperature.

[Land Owner]

Are you fluxing your melt? Crayons, wax, saw dust, anything? Stir it in. Remove the crud. Stir to keep elements from disassociating in the melt. You should flux. We do.

[kcofohio]

while many do cast without a thermometer (or PID), it really helps knowing the temperature of the melt, because the Dial on the Lee melter is not consistent with anything. Also, because of the placement of the thermostat and heating element on the Lee pot, the temperature of the alloy will increase as the alloy level goes down...this happens when keeping the dial in the same position. So many people will turn the dial down a tiny bit as the level goes down, to maintain a constant temperature.

I kind of wondered about the heat and temperature part. I could see the pot getting red when it started out empty, and that was near the bottom. I bought a non contact thermometer, but it doesn't like shiny surfaces. The PID I may have to look into sometime after things get somewhat normal.

[kcofohio]

Are you fluxing your melt? Crayons, wax, saw dust, anything? Stir it in. Remove the crud. Stir to keep elements from disassociating in the melt. You should flux. We do.

Pine sawdust, mainly. Some popular. I got it pretty clean. I have read much on this site, and one was about the fluxes you all use.
My daughter does have some candle wax, soy base, that she left here. I just haven't looked through the boxes to find it. But thank you for checking.

[JonB_in_Glencoe]

I kind of wondered about the heat and temperature part. I could see the pot getting red when it started out empty, and that was near the bottom. I bought a non contact thermometer, but it doesn't like shiny surfaces. The PID I may have to look into sometime after things get somewhat normal.

I found that my aftermarket PID update was an awesome improvement to my Lee pot, but I rarely suggest it, as it isn't necessary (it's like comparing a car with automatic transmission to a car with a manual) and it will double or triple the cost of a Lee pot to a newbie who probably choose the Lee pot due to cost.

I will add another large improvement to my casting hobby, since you are a newbie. Preheating the Mold on a thrift store Hot plate. Once you figure out what setting to adjust it too, it's awesome to start a casting session with the mold at the correct temp, no wrinkles or other rejects, just good looking boolits after the first couple pours. When I was starting out, I would have to cast for 20 or 30 minutes to get good boolits to drop freely from the mold. NOW, some will say that setting the mold on top of the pot does the same thing and I found it did help somewhat, and so does dipping the corner of the mold into the melt, But there is no control over what temp your mold ends up at...doing those two things I found I was still casting rejects for many many pours. The Heat plate idea was a Godsend for me, I also added a modified steel coffee can to create a oven effect (hold in Heat) on top of the Heatplate.

[kcofohio]

Thanks JonB for the tip. I will keep an eye out for one as I also am looking for pewter and a used convection oven.

[lightman]

All good suggestions above. But don't knock your self out looking for a used hot plate. You can get a new one from Walmart for 12 or 14 dollars. But if you see a used one for a lot less you can grab it.

[jsizemore]

I like that web site. I should consider Lyman's casting manual. There is so much here on this site, it's hard to take it all in.

Your not gonna learn it all overnight. Reading is fine but experience is just as important.

[kcofohio]

Your not gonna learn it all overnight. Reading is fine but experience is just as important.

I totally agree! Contrary to popular belief, you can teach an old dog new tricks. You just have to have the right treats.

[CaptRob]

Your not gonna learn it all overnight. Reading is fine but experience is just as important.

absolutely, i cut my teeth on everything reloading here on this site. all the info you need to do anything casting and reloading is here somewhere, but until you put it into practice, only then will the true learning begin

[RogerDat]

Hot plate with a "solid" surface is better for molds. The old style spiral heat elements can be better for lead. Newer solid surface hot plates tend to cycle on/off to maintain a temperature. Lower temperature is more off time. The older style spiral heating element tent to dial to a specific power level and that power remains constant. Lower temp is less power going through element but importantly always the same amount of power.

If you have a small pot you use to melt pewter or scrap solder, or the hot plate has sufficient wattage to melt small batches of lead then the old style spiral heat element has an advantage. I think the knobs will be bigger on the older style with a rheostat. The little thermal switch modern version doesn't need much knob to turn it and won't be turning a full turn as a rule. The rheostat control will turn 360* or more and takes a bit of leverage so larger knob. On the ones I have seen anyway.

An old circular saw blade or piece of sheet metal on the coil style hot plates is really needed to avoid too much spot heat on the mold. Warping or even damage could result from sitting right on the element. A solid surface hot plate doesn't require this.

A tip I learned here was take a larger can such as stewed tomatoes or small coffee can and cut a notch on the open end to insert the mold through. The upside down can over the hot plate and mold will form an "oven" that will help the whole mold have an even temperature and heat up quicker. I also cut a block of wood for under the handles that maintains the mold level on the plate. Otherwise I found the weight of the handles would cause the mold to to pick up on the end opposite the handle and not make any contact with the hot plate except on the back edge.

If you can find the right temperature setting for the mold on the hot plate and mark it the faster less frustrating starts plus the ability to take a short break without the mold cooling off is well worth the cost of the hot plate. Warping from over heating is possible so not too hot or leaving the mold for extended periods isn't smart but to go get more lead, hit the can, or let the dog out it is great to come back and pick up where you left off with the mold up to temp.

[bazzer485]

I just bought a $17 hotplate from Amazon, it’s got a variable heat control, on number 5 on the dial it keeps a NOE five cavity mould at 360-370’degrees f indefinitely. So if I take a short break from casting its all ready to restart as soon as I like.
Barry


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[Cosmic_Charlie]

After you've fluxed and mixed the pot try floating a layer of kitty litter on the top. It will keep the tin from oxidizing. I cast anywhere from 600 to 700 deg. depending on what the mold seems to like. With Lyman #2 alloy the bullets come out shiny.

[RydForLyf]

while many do cast without a thermometer (or PID), it really helps knowing the temperature of the melt, because the Dial on the Lee melter is not consistent with anything. Also, because of the placement of the thermostat and heating element on the Lee pot, the temperature of the alloy will increase as the alloy level goes down...this happens when keeping the dial in the same position. So many people will turn the dial down a tiny bit as the level goes down, to maintain a constant temperature.

Actually, Lee pots have no thermostat. You can see there are no wires running from the pot back to the "console", only heating element rod. The dial on the Lee pot has no feedback meaning temperature reading. It is basically a cycling timer. It controls how frequently the heating element cycles on and off, based on time only. This is why you have to turn it down as the pot level lowers. Since there is less lead to heat, the temperature rises.

[Chill Wills]

Actually, Lee pots have no thermostat. You can see there are no wires running from the pot back to the "console", only heating element rod. The dial on the Lee pot has no feedback meaning temperature reading. It is basically a cycling timer. It controls how frequently the heating element cycles on and off, based on time only.

The best I can tell, the LEE pots have a bi-metal switch that open and close as the heat in the housing goes up and down. Maybe that is what you are describing too?
I've adjusted the range setting on troublesome Lee pots by bending the switch arm very slightly to get the working range back in center. In my experience, no two LEE pots are the same temperature at the same number setting as they come new.
IMO - They are still very good lead pots and well worth the money.
I will second the idea of using a lead thermometer as a new caster.