Cooler is Better

[JohnH]

Took a hint from Bruce and tonights casting session included a shallow dish of water soaked rag which I touched at every cast to cool the sprue. I was using my Lee 429-200-RF double cavity mold and it cast very nicely this evening. I wasn't trying for speed, and probably was holding the tip of the sprue plate a bit long, but it seemed to help a great deal. Normally with this mold I have trouble with it being too hot. Not so tonight. I was able to make cast after cast after cast in an even rythem. And the bullets, Oh My how pretty they are. Nicely filled out, no shrinkage of the middle driving band from too much heat, no two toners. Just nice gray/off silver bullets without that frosted appearance which were consistantly filled out cast to cast. I have in past tried cooling this mold by touching the mold bottom to a damp rag, but found that to remove too much heat. Never occured to me to just touch the sprue plate . The more I read here, the more I have to forget everything I think I know.

[Newboy]

"Not filled out in the middle due to too much heat". I have had this before, and thought I had bad alloy. Thanks a lot!

[Willbird]

Personally if I'm water dropping them I like to get a touch of frost. It just depends on the boolit size from my limited experience if you need to cool the blocks or just the sprueplate.

Bill

[Magnum Mike]

Personally if I'm water dropping them I like to get a touch of frost.

Why? Seems like i end up with a lot of frosted boolits and i havent really figger'd why yet. I was guessin that it was from the mold bein to hot...

[wills]

"Not filled out in the middle due to too much heat". I have had this before, and thought I had bad alloy. Thanks a lot!

Welcome aboard. Where in Texas are you?

[Willbird]

If you are water dropping, or even oven heating then quenching, the hotter the boolit is when it hits the water the harder it gets, the frost is the only visual clue you have as to how hot the mold is running.

Frosted boolits are not bad boolits, if running straight WW alloy I feel the hotter you can pour the nicer they fill (most electric setups max out at 800 or so I'm told)


Bill

[beagle]

The water trick works just fine for cooling the moulds but I have a thing about water in and around the loading bench.

To accomplish the same purpose, I made a small casting table with a small high speed cooling fan from Radio Shack mounted in the surface. A piece of 1/4" mesh wire is mounted over it. When casting big bullets, I'll sit the blocks on it for a few seconds betwen casts and it seems to work just as well without the water.

For smaller bullets, I have a slab of aluminum plate that I use to sit the mould on and it dissipates heat from the blocks pretty good as well.

We once messed with attaching two aluminum heat sinks from Radio Shack to the bottom of a mould using long handle attaching screws. This worked pretty well with the 45-500 grain .45 bullets. The paint was removed for faster heat dissipation. It worked but made the casting rig a little bulky and due to different sized blocks, we had to modify the rig several times. With these disadvantages, we stopped using it but it works to get rid of the excess heat.

Just some ideas you might use without haveing water in the vicinity of molten lead as "caca happens"./beagle

[Willbird]

I had that same thing about water around molten lead, but the way I do it the quench bucket is 24"-36" BELOW the lead pot, and the mold is too hot to hold any water. The quench rag is probably 12" lower than the pot.

and dropping the boolits in the quench bucket from the mold sure beats heating thousands of them in the oven in the house to heat treat them. actually tens and eventually hundreds of thousands of them.

to each his own.

Bill

[carpetman]

Willbird--actually beats heating thousands--even ten thousands and eventually hundreds of thousands of them. Heck Ol Starmetal will be able to top that easily,no step at all for a stepper.

[StarMetal]

Why shoot yeah. I have special metal trays to hold the bullets and I take them to a local heat treater. He turns the furnace down to what is acceptable to heat treat my bullets. At the end of the convey belt we put a cattle water's tank full of iced water. I've figured we're at least heat treating in the 100 million of bullets. I have a bunch of the locals volunteer to haul all these bullets up and back in their pickups (Waksupi size pickups that is). I'm beginning to think Carpetman is spying on me as he knows alot about my gun hobby and casting.

Joe

[carpetman]

Willbird---See, Joe not only easily topped your output,but left himself a future out if you try to go one better. His was "atleast" just try to top it. But will say his output pales to what mine is. He only uses a cattle water tank full of ice. I have glaciers towed in from Alaska to cool mine.

[StarMetal]

Carpetman

What's it costs you to have those glaciers hauled in? I'm now having the Air Forces largest cargo plane fitted with heating ovens and we're dropping the heated bullets onto the South Pole. We've hired Eskimo's to dig them out and ship them to the States. Low attitude drop as to not damage the bullets.

Joe

[JohnH]

Personally if I'm water dropping them I like to get a touch of frost. It just depends on the boolit size from my limited experience if you need to cool the blocks or just the sprueplate.

Bill

Frosting seems to come in a couple of stages, first is where the mold gets hot enough that the middle driving band will shrink as result of too much heat in the area of the mold, second is where the mold is evenly hot so that eh bullet is evenly frosted, but not grainy. Third of course is grainy frosting. Surface of the bullet feels like fine sandpaper.

Yeah, an evenly frosted bullet, is going to make a harder bullet waterdropping, it is hotter, and heat treating is dependant on the temperature differential between the bullet and the quench medium. However, I don't think that for informal shooting a few BHN is going to make a huge difference one way or another. Hardness is only one component of fast bullets, and probably the more forgiving.

Since I don't have a hardness tester as yet, I cannot find out what I really want to know, how much and what difference does cooling the sprue make in water drop quenching from the mold.

The one thing I forgot to add last night is that I noticed a significant time difference in the cooling of the sprue between two spru blobs and a single mass on the sprue plate. So as I was casting, I made a point of dribbling a bit of lead between the sprue blobs to join them. I'm thinking of milling a little trench between the pour holes to make joining the sprues easier.

Joe, I'm gonna take up casting in a walk in freezer. I won't even have to water drop.

[West Creek]

You guys are workign at this just a wee bit too hard. I just hire the local migrant workers during the winter months to handle my heat treating. They have a set up in the old hog barn - kinda like a production set up using the water from the Wabash River fer coolin and choppin lumber fer the furnaces.

Yep keeps'em busy all winter and I dont even work up a sweat - hehehehe

Tried it yer guys way but the lagistic were too complicated so I just decided my own production center might not be as batch size productive but am able to maintain a steady flow and the the end result is better production over all


West Creek

[carpetman]

Starmetal--Why would you ask the cost of a glacier hauled in? You certainly are not doing things the economical way. You are hiring Eskimoes to work at the South Pole? I hate to be condescending (that means talking down to you),but any offset you might gain if their labor is cheaper is consumed by the cost of transporting them around the world. Besides they are oriented for the North pole. While on the South pole they are in effect standing on their heads and instead of digging up bullets they would be burying them deeper.

[slughammer]

a small high speed cooling fan from Radio Shack mounted in the surface. A piece of 1/4" mesh wire is mounted over it. When casting big bullets, I'll sit the blocks on it for a few seconds betwen casts and it seems to work just as well without the water.
/beagle

I'm in on the cooling fan idea. I'm convinced I trashed 2 Lee 6 cavities by quenching the sprues.

I have my bottom pour pot up on a riser and a small fan blows on the mold and lead stream while I pour. Small adjustments in distance and angle handle fill out issues.

[Willbird]

Well MrOliver 77 and I are working on a project where we run two superconductor wires, one to the earths core for heat to melt, and heat the house and shop, and one to the antarctica for chill to quench boolits, and cool the house and shop in summer.

that way in the winter I will just keep my 10,000 lbs of clean alloy molten at all times, and covered with 1 metric ton of kitty litter.

Bill

[Newboy]

Welcome aboard. Where in Texas are you?

I live south of Houston, but my heart is still in WEST TEXAS.

I normally lurk, but I have learned a lot over the years here.

Ifyou don't know enough to ask good questions, why bother everyone else?

[Bass Ackward]

I'm in on the cooling fan idea. I'm convinced I trashed 2 Lee 6 cavities by quenching the sprues.

You are probably correct.

Cooling the sprue plates make them subject to warping. Same thing happens to the cavities if the metal has stress in it too. I have only ruined the cavities in one Lyman from touching it on a pad, but several sprue plates had to have another round of trueing up to lay flat again. One buddy had his blocks warp bad enough he now has constant finning.

Some molds can take it, ..............

[JohnH]

I'm trying to understand how it is the sprue plate can be warped and I don't completely understand. I can see how the plate for the Lee 6 banger would warp, it is aluminum and long, and if the heat is drawn from one location, it won't cool evenly. It seems though that steel would have a much greater resistance to warping, especially if was stress relieved in the first place. It strikes me that a sprue plate would be nearly useless unless it were stress relieved, for without that it would not be flat from the first time it were heated. But we are talking rather mild heat levels, probably not greater than 250 dF, if that. (I am refering to the operational temp of the mold) I suspect that if any warping of sprue plates or blocks is being experienced the molds are being run in excess of 400 dF. Course I may be full of it too.

Removing the paint from the heat sinks was a mistake, the paint actually increases their efficiency, part of why race engines, both water cooled auto and aircooled cycle engines are painted black

I did years ago replace the sprue plates of my Lyman and RCBS molds with an aluminum sprueplate I made for them. That really made a difference is how well they cast. I've been reluctant to do this with the Lee molds as it strikes me the mold and plate would gall. I don't readily recall, but I think I used either 3/16" or 1/4" T6061 2" wide flat stock.