WW's Not Giving Sharp Bands

[cbrick]

That's a good idea about cooling whatever part of the mold that may be giving hot spots and all I have to do is side step a few feet close to where the fan is.

Hhmmm . . . Side stepping, not exactly how I go about it.

I have a small fan with about a 4 inch diameter blade that is set to blow right where I open the mold and drop bullets. It is also placed just far enough away that it is just a gentle flow of air where I dump the bullets. If I notice the sprue may be getting a bit too hot I hold it towards the fan for just a couple of seconds, Not trying to get a cool sprue, simply keep the heat in it from rising.

I preheat the mold and start casting with the fan turned off. With a pre-heated mold and 3-5 pours or so the mold is at proper temp and then I turn on the fan to keep it at the proper temp. The number of pours before turning on the fan will vary, in the winter with a cold shop it may be 20-30 pours before the fan is needed, in the summer in a hot shop it will be much sooner.

The whole point of the fan is to keep a properly heated mold properly heated with a gentle flow of air. If the sprue or the bottom of the mold need cooling just hold it in the air for a tick longer.

As a side note, if your casting HP do this with the cavities closed, bullets in the cavities and the pin in the blocks. If your using the Cramer HP system keep the blocks closed, never leave the pins in this flow of air, they will cool very rapidly. HP pins have very little mass to hold heat and get too cool very fast.

Rick

[ColColt]

This is just a follow up on all the excellent advice I was given. the other day I received a 44 cal mold from Dan of Mountain Molds and was able to give it a try today and what I had gleaned from this thread.

I was most happy with not only the mold as it dropped the boolits without having to tap on the handle pivot hardly at all. Early on(first 50 or so) all I had to do was to open the handles and they dropped out. It was only after that or more I'd had to tap a time or two-no big thing to me as perhaps the mold had gotten hotter. I put to use the method of letting the melt swirl and tilted the mold maybe 10 degrees or so left and then right(two cavity mold) and voila-no hot spots. I kept the melt at approximately 650-675 most all the way though and all in all I couldn't have asked for a better casting session. I did apply Bull Plate early on which helped as all know.

Hat's off and kudos to Dan and all those that gave such marvelous advice in this thread. Of all the forums related to guns I've been to I classify as roses-this one is an orchid.

[gray wolf]

Rick -- Gary-- and-- Gear

Way good advise, I use it and it works. I have cast for hours with a pot temp of 625*-650*
And only had to adjust was my casting speed and the size of the sprue puddle.
I think all they have written will help anyone that is willing to listen.


Sam

[Whistler]

I tried the advise posted in this thread on today's casting session. I was casting .429 208gn wadcutters from an aluminum mold and had very little success. I tried swirl pouring and cast as fast as I could, but could not get proper fillout. I tried temperatures from 650 up to 900 degrees, and it was first at 850 that I was starting to get acceptable fillout. At 900 most boolits were perfect and every third to fourth fill I cooled the sprue plate on a wet sponge which gave me nice sprue cuts.

[onondaga]

I wish I could watch you work and bring my own thermometer. I don't know of a pot that will heat to 900 in any models mentioned on this board except gas fired.

Bullet alloy poured at 900 is beyond any extreme I have ever read about. My setup beyond 775 will not cast anything even resembling a boolit unless I am casting pure lead. I have cadence of about 3.75 drops a minute and rarely need to adjust up or down from that. That 900 degree temperature may have oxidized off everything but pure lead and you are casting pure lead.

Pure lead at 900 degrees cast into a room temperature mold will work reasonably well. Any boolit alloy cast at that temperature of 900 in a warmed mold gives me images of a hot liquid sprue puddle for a long long time and white raisin looking things in a bowl made with fried boolit alloy.

Your method doesn't jive to me at all unless you don't use a thermometer and your dial setting is #9 and really much less than 900 degrees . 900 degrees even makes aluminum of the mold warp and get difficult to align and very sticky to itself and any boolit alloy, let alone the lightening fast oxidizing of the Tin in the molten alloy at 900 and exposure to air. Aluminum itself noticeably oxidizes at 900 degrees. Physical properties of alloys, thermodynamics of casting and experience instructing casting just won't allow me to believe what you have written. I question your motive.

Gary

[geargnasher]

I'll never understand people who do everything they can to discredit the long-established and proven facts of chemistry and physics. I'd like to be there too, any time anyone tells me they don't get good fillout until the pot is at 800 or 900 degrees, because there is something going on that isn't being translated to the posts.

Gear

[cbrick]

There are people that find it humorus to try and mess up the efforts of new casters and people that are trying to learn.

If there weren't people like that explain computer virus's. Those that spread them can gain nothing by doing so except a warped mind telling them they crashed someone elses computer and that's really funny.

Rick

[Whistler]

I've got the NOE Lead Pot Thermometer, it sits at the left edge of my Lee Pro Pot IV. I have left it inside when the melt solidified and watched it as the melt goes into a total liquified state around 650 degrees indicated from the thermometer. When cranked up to max (9), the Lee pot takes about ten minutes to reach 880-900 degrees. Outside temperature was about 80 degrees.

From my estimation, this leaves the thermometer showing about 50-60 degrees too high. So my previously stated 900 degrees would be about 850. I have no dross on my melt, the sawdust on top is just sawdust.

geargnasher: If you believe me to actively discredit any of the fact presented in this thread, from you or anyone else, then you are mistaken and I apologize if I have given that impression. I am not a chemist, I am just an amateur boolit caster and hobbyist trying to remove the sources of error that I myself and apparently others suffer from. If we together, as you wrote, can translate those errors into these posts, then we have all gained valuable knowledge, even you experienced casters who do get right fillout without extreme temperatures.

[Echo]

WW's in themselves don't have any tin that I know of. That's why I added about 3% but this alloy contains no antimony. Linotype had approximately 4% I believe but also has 12% or so of antimony and I attributed that to better fill out of the bands since WW's + 3% tin has none.

Well - 3oz of tin into 160 oz of WW's is closer to 2% tin. And WW's are said to have 4% antimony.

I adjust the bar on the Lee 4-20 pot so that the mold is about 1/2"-5/8# away from the spout and that seems to work pretty good. The amount of boolits per minute is about the same with all alloys so, I don't think speed was a part of the quotient as for this problem. It's sort of odd in that one side of the top band may have been sharp but the other side wasn't...weird. I did get some respectable boolits after about 20 or so but still not as well defined and sharp as with the lead/Linotype alloy.

I don't cut the spruce until I see it turn dull grey whatever time that takes...five seconds or 15 seconds.

Fifteen seconds? Three to five seconds would be about right. Hard to understand how one would go about keeping a sprue unfrozen for fifteen seconds.

It all depends on the alloy and mold temp. Maybe it was just a fluke as I don't recall having that problem before. I haven't used ww's all that much but mostly use 50/50 lead and Linotype for about BHN15. If I wanted it softer, just added more lead. I've had an abundance of Linotype for years due to working in the printing business many years ago and got quite a bit of it that I made into 50/50 mixes but still have the type by itself to mix whenever I need it. WW's are hard to come by in my neck of the woods and a 5 gallon bucket will usually yield only about 25 pounds of it if you're lucky and the rest steel, iron and other junk. What I currently have is from Kathie and it checks out on average as BHN9.4...at least my sample do.

You did hit upon a valid point and one I'm guilty of-added sprues to the pot while I work. It's an old habit that needs breaking.

Not sure I agree with Gary here. I return the sprues directly after knocking. They are still hot, maybe not up to the 675 in the pot, but aren't going to reduce the melt temp significantly.

[cbrick]

Not sure I agree with Gary here. I return the sprues directly after knocking. They are still hot, maybe not up to the 675 in the pot, but aren't going to reduce the melt temp significantly.

Return sprues to the pot? Yes I do, no I don't.

When bottom pouring I don't, I leave a good thick layer of charred sawdust on top and sprues and rejects go back in the pot when I'm finished. Nothing goes back in the pot while casting.

When ladle casting I hold the mold over the pot to pour and as soon as the sprue freezes I open the sprue plate with a gloved hand and drop it right back into the pot. I am using the ladle to keep the melt stirred, the sprues are quite hot as in just short of liquid and with a 40 pound pot the melt temp isn't effected enough to notice if at all.

Rick

[geargnasher]

Echo, I returned sprues straight to the pot for years, in fact until recently. Then I discovered that all those little specks of crud on the surface of my boolits were oxide inclusions from the returned sprues and cull boolits. The cool (or solid) lead will sink in the molten due to density variances, and it takes the oxide coating straight to the bottom, where at least some of it is trapped under the surface of the melt due to the surface tension and weight of the lead on the bottom. This oxide layer doesn't melt, and since there is no way to reduce it at the bottom, it just sits there, slowly migrating toward the spout as the pouring currents take it there. When I quit returning sprues, my boolits cleaned up. I run a very clean pot, stirring and scraping the sides with a stick will keep all the clingy dross wiped off, so the only source for the junk was the oxides of the sprues. Now, I add sprues all at once when I'm refilling the pot with warm ingots, then stir-scrape the bottom with a teaspoon and bring the junk up the sides. Also, I flush the spout prior to casting, running out about half a pound and returning it while still liquid to the top.

Whistler: I too have an NOE thermometer, in addition to a Lyman one and a PID controller with submersible thermocouple. Your readings don't jive AT ALL. Pure lead melts at about 621 degrees F, and the addition of antimony and/or tin LOWER the melt point from there. There isn't a lead-based boolit alloy of which I'm aware that is fully liquid at any point ABOVE the melt/freeze point of pure lead, so something is "rotten in Denmark" as they say. WW alloy begins to "sweat" tin or Sb/Sn (depending on composition) at about 500, is mushy by 550, stirrable by 560, and it hangs out at 570 until suddenly all the much disappears and the last phase of liquifaction takes place. At that point the alloy can take on more heat and the temp rises. I think you need to calibrate your thermometer with pure lead (be CERTAIN it is submerged at least up to the minimum line on the probe!!) or close to pure (roof flashing, for example). If your thermometer shows anything over 621 for a melt point, it needs calibration.

100 degrees over full-liquidus (you can determine full liquidus point of ternary alloys by observing the last flatline in the temperature/time curve, indicating the point at which the final element in the mix is changing phase change to liquid, then just as the temp begins to rise again you know it's fully liquid. Note that temp. Go 100 degrees more and hold the pot temp there. Get your mould hot, and start casting until you get good boolits. If you have a decent alloy and good, clean mould, it will work, I guarantee it. This is where your casting pace and technique are put to the test. If you're doing it right, you can make good boolits as long as the alloy is barely hot enough to pour out of the pot or ladle.

One more thing, you can do the test in the above paragraph finding the exact freeze point, mush phase, full-liquidus, and casting temperature by making a time/temp graph with the calibration of you thermometer the way it is, just make marks on it with a sharpie and forget what the dial says. Just go 100 over full-liquidus and mark that, so you know where your casting temperature should be.

This is what I meant by things not being translated into posts, you have experience from being there that we, on the other end of a phone line, don't, so it's kinda hard to see the whole picture from a few words. You posted like your readings were FACT, and that those supposed facts made the rest of us fools with what we were saying, so you can see how that might ruffle a few feathers when in truth they were just readings, and experience tells my either your thermometer is about a hundred degrees off, it wasn't submerged deeply enough, or you have something badly wrong with your alloy.

Hope this helps,

Gear

[docone31]

Well, there I differ with putting sprues in the pot.
I liberally put sawdust or kitty litter on my pot. The sprues go directly on the litter. Rather than the sprue button dropping into the melt, it drips into the melt. I water drop my wheel weight and the sprue is damp. Heating untill melting on the litter, or sawdust, eliminates the moisture, and cleans the alloy going in.
I find, doing it this way, my mix gets more and more homogonized. Kinda like stirring, but on a lessor scale.
The bottom crud does colletc. I take a long flat blade screw driver, and when the melt is liquid, I scrape the bottom and sides. Even with a clean start, stuff does come to the top. I let it sit on top with the litter.
That is my story, and I stick to it!