Why no frosting???

[whisler]

I have some .22 lead scrap from a college rifle range. They only use Eley Match ammo and from what I can find out it is an antimomial lead alloy with 1.2 - 1.5% Antimony. I added some Tin at about 1.5% in the form of solder and cast bullets with it.

The molds were 2 cav. Lee, 105 SWC and 125 RF, both cleaned and lee-mented with valve grinding compound. Cast with one mold only not both at the same time.

Preheated mold on a hot plate, inside a little cut down electrical box to contain heat. Hot plate is on high.

Alloy was at 740 deg. F to keep down Tin oxidation. I cast as fast as I could, cutting sprue with a gloved hand. Sprues were flashing at about a 3 count. My reject rate was about 30% due to some fill-out problems.

No matter what I tried, the bullets never got frosty. Seems that I'm not getting hot enough but I can't go much faster. Is it the alloy or am i missing something?

Any suggestions?

[454PB]

If the sprue was solidifying that quickly, the mold was too cold to allow frosting.

Raise the cast temperature some and you'll get fewer rejects.....and frosting.

[beagle]

We tend to associate frosting with mould heat. I'm guessing that since you're using Lee aluminum moulds and casting realitively small in capacity leadwise bullets that the mould blocks are dissipating heat faster than you're creating it with small bullets and your blocks are not getting hot enough to produce frosting.

Aluminum tends to dissipate heat pretty quickly.

I've cast larger bullets in NEI aluminum blocks and got frosting but these were in the 250 grain range.

I don't think it's your alloy as I have cast round balls out of pure lead and got flashing.

My opinion and maybe someone else knows for sure./beagle

[whisler]

Guess I'll try leaving the mold on the hot plate longer. I know I can't cast any faster without making a mess.
The good bullets that I did get looked real nice but shiny. Would just like to get more good bullets per casting session.

[462]

Yep, if you want frosted boolits, you'll need a hotter mould. I prefer boolits with a satin finish -- between shiney and frosted.

[geargnasher]

That alloy should get a light satin frost pretty easily, I believe your mould is too cool as others have said.

A three -count on the sprue freezes is about "right", good for shiny boolits if you can get them to fill out, but not quite hot enough for the low end of the "frosty" spectrum of mould temperature. A five or six count on the sprue flashover is necessary in my experience for Lee two-cavity moulds to achieve a nice, even frost.

What generally happens as the Lee moulds come up to temperature is the boolits are first shiny and wrinkled, then just shiny with round edges, then a narrow window of shiny and well-filled, then the sharp edges start to round-over again and get very white (just the edges of the bands and base usually), then as the mould continues to warm up the whole boolit will begin to show a light, satin frost and the edges will again begin to fill out completely and sharply again. That last is the temp range I strive for, as it's very difficult to keep shiny, well-filled boolits from a Lee mould the way I do it.

With that alloy, 700 degrees should be plenty for the alloy, but you might find that casting at a pace of four pours per minute is required to keep the mould hot enough for lightly frosted boolits.

One more thing, I find it really simple to skip the hot plate with two-banger Lees and just dip the front edge of the mould about 1/4" into the melt for 30 seconds or so, then dip the tip of the sprue plate about 1/2" into the melt for ten seconds and start casting right away. Four pours a minute will keep it hot if it's more than 50 degrees in your casting area. Time it!

Gear

[DrCaveman]

Why do you strive for frosting? The Lyman book says that means the mold/alloy is too hot. Shiny boolits are my goal... Am I missing something?

[DrCaveman]

Btw geargnasher, you seem to show up in every thread I think worth reading. And always have good info. I might want to tag along somehow. Thanks for everything.

[geargnasher]

Why do you strive for frosting? The Lyman book says that means the mold/alloy is too hot. Shiny boolits are my goal... Am I missing something?

The only thing you're missing is that it's a matter of preference. I find it easier to get better boolits that are very lightly frosted, especially using a bottom-pour furnace and scrap alloys of dubious composition (think modern wheel weights)that I've refined myself. If you're using Lyman #2 certified alloy and contact pouring with a ladle, it's easy to get shiny, perfect boolits by running a cooler mould, but it's expensive and time consuming. Like many others, I have had enough experience casting to be able to make match-quality boolits with just about any mould and alloy, but some methods and materials are easier than others.

You will find a difference in size of your boolits when casting antimonial, ternary alloys with cooler or hotter mould temps, and weight also. The key is to do lots of experimenting with casting pace and mould temperature until you figure out what YOU like.

Gear

[edit] DrCaveman, I was having some major internet lag and lost this post the first time, didn't see your "BTW". Pay attention to everybody, I learned most of what I know from the Sr. members here, doing lots of reading, and most of all trying things I read about every casting session. Every time I log on I learn something new, and some of these guys are absolute Masters of the craft.

[runfiverun]

i start most of my luminum molds at the hot end, about where the lead won't solidify.
then go from there.
cool slightly, and then go as fast as i can,pouring a big sprue.
this works well with my two cav 72 gr 25 cal boolit and my 4 cav's too.
the only one i don't is the 45/70 ranch dog, that one i have to cool down with a damp rag.

i see about the same heat progression with the steel molds as gear see's with his aluminum.
even running lower temps like 650-675.
the lower temps allow for a more continous movement without getting the mold temps up and makes it easier for me to get into a flow.

[Bret4207]

Why do you strive for frosting? The Lyman book says that means the mold/alloy is too hot. Shiny boolits are my goal... Am I missing something?

Ya know the saying, "If a little is good, a lot is better."? Well, you can get a mould too hot and if I were making moulds that some clown might get red hot and damage or that people might want a refund on because their boolits weren't "shiny" I'd just try to nip it in the bud and tell everyone frosting was a sign the mould was too hot too!

[beagle]

I'll go along with Bret. You can get a mould too hot. The next step after frosting is incomplete fill out. I like mine well filled out and a little frosty. It's kinda like baby bear's soup....has to be just right./beagle

[1Shirt]

Agree with Beagle as far as "a little frosty". Think that a "little" frosty particularly in the lube groves helps to hold the lube.
1Shirt!

[whisler]

"A little frosty" was what i was aiming for but not able to attain. That's what inspired the question.

I'll try dipping the mold end and sprue plate, and using about 700 deg. alloy temp. If that doesn't work, I'll have to get a better hot plate.

Thanks for the replies and suggestions.

[Bret4207]

Hot plates are nice friend, but nothing beats a good fast casting tempo. Pour, dump, pour, dump, pour dump pour dump pourdumppourdumppourdump, etc. The natural inclination of pretty much every newer caster I see is to dump the boolits and give them the once over to see how they came out. Fagettaboutit. Get the tempo going and the mould will take the heat.

[DLCTEX]

I had trouble getting a mould to stay up to temp this week when my reloading shack was cold. As the heater brought the room temp up to 75 the problem went away. I was surprised. If a warmer casting temp doesn't cure the fillout problem then look to venting and/or try pressure casting.

[williamwaco]

Btw geargnasher, you seem to show up in every thread I think worth reading. And always have good info. I might want to tag along somehow. Thanks for everything.



Doc.

You are exactly right. If you are new to reloading, you want to read everything Gear writes.


PS, In my experience,you are not going to get frosting with a Lee 2 cavity mold until the sprue hardning takes 8 to 10 seconds.


I like a very light frost on my bullets. When I try for shiny, I get too many wrinkles.



.

[largom]

"A little frosty" was what i was aiming for but not able to attain. That's what inspired the question.

I'll try dipping the mold end and sprue plate, and using about 700 deg. alloy temp. If that doesn't work, I'll have to get a better hot plate.

Thanks for the replies and suggestions.


Also pour as large a sprue as possible as this helps to keep the mold hot.

Larry

[snuffy]

'cause momma didn't have enough sugar for the cake AND the frosting.:kidding:

Yeah, temps not high enough.

I got one o' them wallgreens hot plates. Darn thing has such a cheap thermostat on it, I'm tempted to rig another PID to control the darn thing. In fact, I could use the same pid on my lubrisier to control the heater. It's temp swings means I have to set it on high to maintain a medium temp of 300 degrees, but before it shuts down on high, it must hit over 400,,,---. But once it melted the ingots I had "warming" on it, had to be over 600 to do that!

Mold preheating is a hit or miss thing unless you KNOW the actual temp of the mold.

BRB, gotta go look up some stuff on aubers.

[geargnasher]

One of these days I'm going to take a more dramatic (and not so stupidly HUGE) picture with more extreme mould temperature spread, but this one's decent. The left boolit was from the mould being too hot, note the rounded edges and sandblasted appearance of the surface (won't wipe off and be shiny, just stays dull), middle is "just right" as mentioned above, sharp fillout and light, satin frost that wipes off with a twist of a dry rag leaving the boolit like polished silver, and on the right is one cast from a slightly too cold mould, note the wrinkle at the parting line and rounded edges. It is also much more shiny than the others, although with this wheel weight alloy even badly wrinkled boolits from a room-temperature mould aren't glossy like can be with some alloys.

All these were cast if I remember right with an alloy somewhere around 675 degrees.

http://castboolits.gunloads.com/attachment.php?attachmentid=28007&d=1293562439

Gear

[Casper29]

the reason bullets are frosted is because of the antimony is coming to the surface because the mold or the lead is to hot, that is why most people throw the frosty ones back to melt and mix it back in with the tin and lead.

[runfiverun]

allright.
one more time.
it's ALL about mold temp, and cadence.
control that and you can make just about anything work.
even alloys with zinc or copper or little/no tin.
alloy temp affects some things,speed of casting is the main one, and depending on the alloy you might need high heat for it to flow well.
running a mold too hot or too cold will not make good boolits period......
look back at gears post about temp progression, that is mold temperature progression.
as you go through that progression your alloy temp can go down.
not only can it, it should be going down.
we DO NOT need to use 800* alloy temps.
700 is fine.
i get as close to 625 as possible [with an alloy with some tin in it] usually 645-650 is where i end up, because i use as little [heat and tin] as possible for the main part of my casting.

[whisler]

Well guys, I really am casting about as fast as I can go. As soon as the bullets are dumped, I close the mold and pour again. I'm not stopping to look at the boolits until I have to refill the pot. (I read it right here) At that point the mold goes back on the hot plate until the pot is back up to temp.

One thing that slows me down somewhat is the boolits hanging up in the mold, but, as fast as I can get them out, the mold is closed and refilled.

Sounds like my only choice is to get the mold hotter in the first place. Hopefully dipping the mold in the alloy will allow this, or maybe a better hot plate.

The next session should tell the tale. Thanks again

[Bret4207]

the reason bullets are frosted is because of the antimony is coming to the surface because the mold or the lead is to hot, that is why most people throw the frosty ones back to melt and mix it back in with the tin and lead.

I'm not sure of the why of frosty boolits, but most of us here like them that way and would never "throw one back". Appearance doesn't count for beans, but perfect fillout, which often comes with frosting, does.

And no offense, but frosty boolits are a sign of mould temp, not pot temp. You can put 1K F lead allot in a cool mould and get wrinkled, shiny boolits.

[RevGeo]

Hot plates are nice friend, but nothing beats a good fast casting tempo. Pour, dump, pour, dump, pour dump pour dump pourdumppourdumppourdump, etc. The natural inclination of pretty much every newer caster I see is to dump the boolits and give them the once over to see how they came out. Fagettaboutit. Get the tempo going and the mould will take the heat.

Truer words were never spoken (or written). A good rhythm of pouring and dumping is the key to consistency in bullet casting. Personally I don't like the look of frosted bullets, but better a little too hot and too cool, IMO. Sometimes I think about the buffalo hunters and other frontiersmen casting their bullets over a fire made from buffalo **** using brass moulds and whatever alloy they were able to buy - probably pretty close to pure galena - in the dark after shooting all day. I'll just bet they got pretty good at temp control and the rhythm of casting.

[whisler]

Well, I cast with the 105 SWC today and I have 2 problems. 1. Hot plate wont get hot enough. 2. boolits hang in the mold and while i'm getting them out, the mold cools.
Dipping the mold definitely gets it hot enough, but the boolits hanging up delays me enough to cool the mold on those tiny boolits. I got some nice boolits today but the reject rate is still too high
I'm going to work on the cavities until I can get them to jump out, then maybe I can keep the mold hot enough. .
Thanks for the help.

[John Guedry]

If it's a new model hot plate (one with a solid type element) chances are it won't get as hot as you're trying to get. Lawsuit phobia or some such thing on the manufactuers part.

[kappy]

I get frosting with hotter lead which makes the mold hotter.

[geargnasher]

I get frosting with hotter lead which makes the mold hotter.

I don't understand this comment in light of all the facts that have been layed out about unnecessarily overheating alloy and the importance of casting cadence/mould temperature.

Gear