Ian
Notorious member
Take it out of the box, pull off the warning stickers. Read them if you weren't already aware that lead alloy can be harmful to your health if you get it in you.
Clean the cavities and the sprue plate with some kind of brush or Q-tip and alcohol or ether. Don't use starting fluid that has upper-cylinder lube in it. Prestone starting fluid is the only one that doesn't AFAIK. Brake cleaner and carb cleaner will degrease but will leave a film that will need alcohol or ether to remove. You can boil the mould in a saucepan full of distilled or rainwater and a couple drops of liquid dishwashing detergent added, this will turn the aluminum a nice medium grey and do most of the breaking-in for you. Usually I don't bother boiling the moulds, just wipe the cavities out with a Q-tip soaked in denatured alcohol, wipe the preservative oil off the underside of the sprue plate, prep the sprue plate per the next step, and get to casting.
Sprue plates often have burrs on them where the sprue holes are, and on the edges. I touch these up with some 400-grit sandpaper backed by a small wood block. After I'm happy that the burrs won't make big scars on the top of the blocks, I wipe off the grit with alcohol on a paper towel and pre-apply a little sprue plate lube.
For sprue plate lube, several things work. Nothing seems to beat a good FULL SYNTHETIC two-cycle engine premix oil. MODERATION is the key when applying it, or it will get in the cavities and cause havoc. When heated, the oil wicks everywhere. Before the first cast, I wipe a faint film on the underside of the sprue plate, on the alignment pins, and on the wave washer under the head of the pivot bolt. I pay particular attention now and during casting to keeping a light film of the oil between the sprue plate and blocks right around the base of the pivot bolt.
Next, take a BBQ lighter like Aim'n'Flame or whatever you have, open the mould up all the way, hold one side at a time sideways and over your head where you can look up into the cavity half, and wave the flame lengthwise across the cavity a few times, JUST until a light caramel yellow haze appears in the cavity. A little darker soot will form around the cavity on the block face, just make sure you don't get it black. If you do, wipe if off and clear it out of the vent lines, and try again. Do both sides, don't worry about coating the block faces evenly, in fact, the less you get on them the better.
Heat up your alloy. WW alloy does best between 675 and 725°F.
Close up the mould and dip the front bottom edge into the melt about 1/4" deep. Hold it there until that little swipe of sprue plate lube on the bolt washer just barely starts to smoke. This will take half a minute and suck about 40° off the pot temperature of a full 20 pound pot. Remove the mould and the alloy should fall off of it like water and NOT stick. Little flecks of oxide might remain on the part that was submerged, but they should just wipe right off with a gloved fingertip. If it doesn't, dunk the mould again for ten seconds or so. For reference, the mould needs to be at least 400°F to start casting. A side note, just setting the mould on the edge of the casting pot for half an hour WILL NOT get it anywhere near hot enough to cast with, ever. It might make it halfway to casting temp at best.
Now fill the mould quickly, don't dilly-dally after pre-heating it because in 15 seconds it will be too cold to cast with. Fill it up and make a good dollop on top of the sprue plate. The sprue should take at least 3 seconds to solidify, cut it the instant it flashes over dull. Don't wait for it to harden, cut it right when it solidifies. To know when you did it right, flick the just-cut sprue on to a hard surface and it should break up into a few grainy chunks.
Quickly inspect the bullet bases for sharp fillout. The sprue cut should be flat and not a hard, shiny bump. If you get a hard, shiny bump either the mould is too cold or you waited too long to cut the sprue. A little porous dimple is what I strive for because that makes the flattest bases with a Lee two-cavity. Your sprue plate lube will prevent lead from sticking to the plate when you cut the sprues quickly like this.
OK, now you're off to casting. Did I mention putting a big analog wall clock with a second hand on it right above your casting pot? Well, do that BEFORE you start casting if you don't have one already. Now time your pours. FOUR POURS A MINUTE. I repeat, cast at FOUR POURS A MINUTE, that means one complete cycle of fill, cut, dump, close, ready to fill again in 15 SECONDS.
I think most people go wrong with Lee and other aluminum moulds because they really don't have any idea what "cast fast" really means, or how hot we mean when we say "HOT!" Four pours a minute is very fast, but that's what it takes with many moulds. Now watch the sprue and bullet bases. Cut the sprue on the ragged edge of molten. When the mould gets so hot that you have to wait more than about four seconds for the sprue to set (count it, don't guess, four full ticks), you might want to slow down just a little. When you slow down, slow each operation, not any one part of the casting cycle. Watch your clock, know what you're doing and when you're doing it. Don't waste time admiring your casts, just glance at them to see how the edges look, if there are any wrinkles, etc. and keep moving that mould.
If you see wrinkles or "worm lines", it's too cold. Oil will burn off quickly and likely isn't the issue with wrinkles. Sprue plate lube that intrudes into the cavities will make the bullet surface almost crackled, but smooth wrinkle lines are a temperature problem. Lee moulds like heat. If using WW alloy or anything with 2% or more antimony in it, the bullets will have a light, satin "frost" appearance to them. When cool, if you wipe them with a dry rag, they should become very shiny. If they have a coarse, sandblasted appearance to them, your mould was TOO hot. If wrinkled, the mould was too cold. If the bullet base edges are rounded and not razor-sharp, you either filled the mould too slowly, or the sprue plate was too cold and needed a larger sprue puddle formed on top of it. I generally balance as much lead on the sprue plate as it will hold for the first few pours, then just fill the wells plus a big dollop drizzled along to connect the two once the mould is up to temperature.
If that won't work, PM for my address and I'll take the problem off of your hands. I run a Lee Welfare Society at my house where poor abused, mistreated, and neglected moulds are rehabilitated and given a second life.
Clean the cavities and the sprue plate with some kind of brush or Q-tip and alcohol or ether. Don't use starting fluid that has upper-cylinder lube in it. Prestone starting fluid is the only one that doesn't AFAIK. Brake cleaner and carb cleaner will degrease but will leave a film that will need alcohol or ether to remove. You can boil the mould in a saucepan full of distilled or rainwater and a couple drops of liquid dishwashing detergent added, this will turn the aluminum a nice medium grey and do most of the breaking-in for you. Usually I don't bother boiling the moulds, just wipe the cavities out with a Q-tip soaked in denatured alcohol, wipe the preservative oil off the underside of the sprue plate, prep the sprue plate per the next step, and get to casting.
Sprue plates often have burrs on them where the sprue holes are, and on the edges. I touch these up with some 400-grit sandpaper backed by a small wood block. After I'm happy that the burrs won't make big scars on the top of the blocks, I wipe off the grit with alcohol on a paper towel and pre-apply a little sprue plate lube.
For sprue plate lube, several things work. Nothing seems to beat a good FULL SYNTHETIC two-cycle engine premix oil. MODERATION is the key when applying it, or it will get in the cavities and cause havoc. When heated, the oil wicks everywhere. Before the first cast, I wipe a faint film on the underside of the sprue plate, on the alignment pins, and on the wave washer under the head of the pivot bolt. I pay particular attention now and during casting to keeping a light film of the oil between the sprue plate and blocks right around the base of the pivot bolt.
Next, take a BBQ lighter like Aim'n'Flame or whatever you have, open the mould up all the way, hold one side at a time sideways and over your head where you can look up into the cavity half, and wave the flame lengthwise across the cavity a few times, JUST until a light caramel yellow haze appears in the cavity. A little darker soot will form around the cavity on the block face, just make sure you don't get it black. If you do, wipe if off and clear it out of the vent lines, and try again. Do both sides, don't worry about coating the block faces evenly, in fact, the less you get on them the better.
Heat up your alloy. WW alloy does best between 675 and 725°F.
Close up the mould and dip the front bottom edge into the melt about 1/4" deep. Hold it there until that little swipe of sprue plate lube on the bolt washer just barely starts to smoke. This will take half a minute and suck about 40° off the pot temperature of a full 20 pound pot. Remove the mould and the alloy should fall off of it like water and NOT stick. Little flecks of oxide might remain on the part that was submerged, but they should just wipe right off with a gloved fingertip. If it doesn't, dunk the mould again for ten seconds or so. For reference, the mould needs to be at least 400°F to start casting. A side note, just setting the mould on the edge of the casting pot for half an hour WILL NOT get it anywhere near hot enough to cast with, ever. It might make it halfway to casting temp at best.
Now fill the mould quickly, don't dilly-dally after pre-heating it because in 15 seconds it will be too cold to cast with. Fill it up and make a good dollop on top of the sprue plate. The sprue should take at least 3 seconds to solidify, cut it the instant it flashes over dull. Don't wait for it to harden, cut it right when it solidifies. To know when you did it right, flick the just-cut sprue on to a hard surface and it should break up into a few grainy chunks.
Quickly inspect the bullet bases for sharp fillout. The sprue cut should be flat and not a hard, shiny bump. If you get a hard, shiny bump either the mould is too cold or you waited too long to cut the sprue. A little porous dimple is what I strive for because that makes the flattest bases with a Lee two-cavity. Your sprue plate lube will prevent lead from sticking to the plate when you cut the sprues quickly like this.
OK, now you're off to casting. Did I mention putting a big analog wall clock with a second hand on it right above your casting pot? Well, do that BEFORE you start casting if you don't have one already. Now time your pours. FOUR POURS A MINUTE. I repeat, cast at FOUR POURS A MINUTE, that means one complete cycle of fill, cut, dump, close, ready to fill again in 15 SECONDS.
I think most people go wrong with Lee and other aluminum moulds because they really don't have any idea what "cast fast" really means, or how hot we mean when we say "HOT!" Four pours a minute is very fast, but that's what it takes with many moulds. Now watch the sprue and bullet bases. Cut the sprue on the ragged edge of molten. When the mould gets so hot that you have to wait more than about four seconds for the sprue to set (count it, don't guess, four full ticks), you might want to slow down just a little. When you slow down, slow each operation, not any one part of the casting cycle. Watch your clock, know what you're doing and when you're doing it. Don't waste time admiring your casts, just glance at them to see how the edges look, if there are any wrinkles, etc. and keep moving that mould.
If you see wrinkles or "worm lines", it's too cold. Oil will burn off quickly and likely isn't the issue with wrinkles. Sprue plate lube that intrudes into the cavities will make the bullet surface almost crackled, but smooth wrinkle lines are a temperature problem. Lee moulds like heat. If using WW alloy or anything with 2% or more antimony in it, the bullets will have a light, satin "frost" appearance to them. When cool, if you wipe them with a dry rag, they should become very shiny. If they have a coarse, sandblasted appearance to them, your mould was TOO hot. If wrinkled, the mould was too cold. If the bullet base edges are rounded and not razor-sharp, you either filled the mould too slowly, or the sprue plate was too cold and needed a larger sprue puddle formed on top of it. I generally balance as much lead on the sprue plate as it will hold for the first few pours, then just fill the wells plus a big dollop drizzled along to connect the two once the mould is up to temperature.
If that won't work, PM for my address and I'll take the problem off of your hands. I run a Lee Welfare Society at my house where poor abused, mistreated, and neglected moulds are rehabilitated and given a second life.
