How Hot Is Too Hot

[Saint]

Just trying to get an idea of what most people run there lead pots at. I do most of my casting in the middle of the night just because it seems to be my more active time of the day. My work area is well lit but not quite as bright as daylight. The only time I seem to be able to cast good balls is if I am running the pot red hot. Is this normal when casting roundball out of bout 75% pure 25 %WW. I am working on getting a lead thermometer now but again I don't like ordering things and it seems to be hard to find locally. Will an infrared thermometer give an accurate reading?

[mooman76]

I don't know how accurate those infareds are but it does take more heat for pure lead and with you running 75/25 you are getting close to pure. WW's I believe are something like 92-95 % pure depending on the alloy that was used so you are bumping it up to about 98% or better. If it needs to run wide open, it needs to run wide open. Keep doing what works!

[BruceB]

My RCBS casting furnace operates at MAXIMUM temperature virtually all the time, and it usually is full of wheelweight alloy. The 'maximum' setting delivered 870 degrees a couple years ago, when checked with a friend's thermometer.

I don't own a thermometer, nor do I own a hardness tester. I have never felt the need for either device in my 40 years of casting. I DO have an electronic scale, which informs me that my bullets are quite uniform in weight, just as my ol' Mk1 eyeballs tell me they're properly filled-out in all respects. My eyeball check while sizing actually catches more defects than weighing them....and they're very minor defects in most cases.

[Sundogg1911]

I rarly cast much above 650F. Most of the books that i've seen tell you to cast at the lowest temperature that will yield good bullets. Bruce B., I'm curious as to why you cast at such a high temp? I'm not saying theres anything wrong with that, but I seem to get some really ugly frosted boolits at a temp. that high.

[NVcurmudgeon]

I use an RCBS thermometer mainly as an aid in maintaining the temperature that each mould prefers. However, now that I use Bull Plate Lube I am finding that the melt can be run hotter without causing lead smears on the top of the blocks or bottom of the sprue plate. Most of my casting is done between 700 and 750 F. (Caution, all thermometers don't read the same.) It is a help to know the temperature when smelting because you want to keep the melt below the melting point of zinc. IIRC zinc melts at well over 800 F. I like to keep WW for smelting around 650 to be safe. Truth is, the thermometer is a convenience, but not a necessity. The mould and the boolits will tell you when everything is right. Smelting? Just hot enough to melt lead WW, and then you can toss all the floaters.

[38 Super Auto]

I run my Lee production pot full tilt boogie until the sprues take too long to solidify. Then, I back it off a little until the sprues solidify in 8-10 sec or so.

When I add ingots to the melt, I crank it back up for a few minutes. My pot has a lot of thermal mass and I add alloy 2-3# at a time, so I can continuous cast.
I am running a JIT alloy delivery to the pot. I usually cast pretty hot.

I don't use a thermometer. I would if I could find a cheap one.

:Fire:

[FISH4BUGS]

I rarly cast much above 650F. Most of the books that i've seen tell you to cast at the lowest temperature that will yield good bullets. Bruce B., I'm curious as to why you cast at such a high temp? I'm not saying theres anything wrong with that, but I seem to get some really ugly frosted boolits at a temp. that high.

To me, a slightly or even moderately frosted bullet is just the perfect temp. I run the Lee 20lb pot at about 7 on the temp dial. I have learned that is the best temp for casting. I use 5lbs ww to 1 lb linotype (allegedly Lyman #2 alloy) and run fast in my casting. I use only 4 cavity and up (all pistol calibers) and have some 10- cavity H&G moulds. I don't think I have ever gotten the H&G 10 cavity moulds so hot that they start to frost.
Like a cake, frosting is good!

[Saint]

I have found that if I don't run full blast I get badly wrinkled bullets. I have a lee 4 lb micro pot. I don't hardness test either as I too use a scale. My bullets either cast shiny and wrinkled or smooth and frosty.

[leftiye]

Plus 1 on what the Bugfisher said- hot enought to frost some, then cooler to as little frosting still gives nice fill out. Kinda between shiny and frosty. Wrinkles are from cold, though it can just be a mold that is too cold.

[Howdy Doody]

I have a Lyman Thermometer that I bought when I bought my initial set up when I started about 4 years ago. I found that with a Lee 20# pot that 700 turned out some nice boolits. Then I got a used RCBS pot and to get the same boolits I have to run the pot up to closer to 725. I can't figure why, but that is what is reading on the thermometer. I should say that I have my best just shy of getting a bit frosted.
I could have lived without the thermometer, but since I have it I check things once in a while. I would really like to have a hardness tester and that is on my list of things to get.

[Marlin Junky]

I ladle cast with a Rowell#3 and MasterCaster running about 800F or a bit less and don't need to fiddle with temp much but for the most part I use heavy molds. WW metal does fill out better if poured hotter than tin rich alloys but I've never found a need to set the pot hotter than about 840F. Under these conditions I may overheat a DC Lyman mold and would probably drop the temp down in the pot to about 750 to 780F. Temperature is really a personal thing but I think fledgling casters who are ladle pouring into ferrous or brass molds should start out will a good pot that will maintain 800F reasonably accurate (+/- 10F). If you are starting out with aluminum molds you should back off on the temperature to somewhere in the 700F to 750F range and have a box of wooden matches handy or you may get frustrated by poor fill-out.

MJ

[Newtire]

I noticed that if I get the melt too hot, the boolits don't drop from the mold too easily. I like those frosted boolits but find that at a certain point while the pot is cooling down after shutting it off, it drops the boolits out really nice. So now I think I will get a thermometer next time I get a little extra loot. Who makes a good one for the money?

[Lloyd Smale]

i cast just hot enough to get good bullets. Usually in the 650-700 degree range.