Shiny vs Frosty

[d_striker]

I use two different lee six banger molds. Both of them are a tumble lube bullet.

It seems like when they come out shiny, the micro groove section is more defined with "deeper" micro grooves than when they're frosty. Any comments?

[Gunslinger]

Shiny or frosty is simply a question of temperature... nothing else! When the mold and alloy are not up to temp, the boolits will come out shiny. When everything starts to get a little on the hotter side boolits come out frosted. Another indicator of the alloy/mold not being hot enough is bad fill out. If you experience this turn your pot up a little.

Some people re-melt the frosted boolits which I find is a waste of time. Frosted boolits shoot just as well as un-frosted boolits... okay they are not as pretty but the cosmetics is about the only difference.

I always cast with at least 2 molds at the same time. This allows me to cast faster without running everything too hot.

[Ricochet]

I think the frosting must come from slower cooling, letting the crystals of antimony get bigger. When I'm making sure a mould's up to temperature, boolits I drop on a towel often look frosty, but the water-dropped ones are always shiny. If they stay in the hot mould longer, they spend more time in that "slushy" stage or in the temperature range where the "solid solution" is getting supersaturated, and I'd expect coarser crystals to form.

[Humbo]

When casting with aluminum molds, I usually don't mind a little bit of frost. But my experence is, when casting with steel mold in particular, partial frosting is causing that part of the boolit to be badly undersized, as much as .002 smaller than the rest of the boolit. I try to run my melt just above liquidus temperature, and rather adjust mold temperature for perfect fillout. With this practice, I rarely have to cool down the mold, just the sprue plate when cutting the sprue is getting too easy. Aluminum molds need to be run hot, but the alloy itself doesn't usually need to be hotter than 650 degrees for good fillout when mold is up to temperature.

[Bret4207]

I don't worry about appearance, I worry about fillout. If my boolits frost, but have complete fill out I'm happy. I've never noticed a size difference but will check from now on.

[EMC45]

I don't worry about appearance, I worry about fillout. If my boolits frost, but have complete fill out I'm happy. I've never noticed a size difference but will check from now on.

Exactly what I was gonna say!

[SCIBUL]

+ 1 ! Since they shoot well I don't mind.
:lovebooli

[Calamity Jake]

Complete even frosting is good IMO as long as there is no crystalin appearence on the surface.

Frosted in spots is a no-no!!

[243winxb]

It seems like when they come out shiny, the micro groove section is more defined with "deeper" micro grooves than when they're frosty. The hotter the alloy/mould/frosty, the more the bullet will shrink on cooling giving a smaller diameter bullet. The shrinkage takes place in the mould as the alloy cools, pulling away for the mould surface.

[rockrat]

My water dropped boolits drop frosty and stay that way.

[Bill*]

It seems like when they come out shiny, the micro groove section is more defined with "deeper" micro grooves than when they're frosty. Any comments?
caliper or mike them...Some of it could simply be an optical illusion due to the surface finish. Sounds crazy but I've fooled my eyes with things like that.

[d_striker]

caliper or mike them...Some of it could simply be an optical illusion due to the surface finish. Sounds crazy but I've fooled my eyes with things like that.

9 replies and you're the only one that actually read my question. To all others, yes I know what causes frosty bullets.

Bill-I was wondering if it was an illusion myself. I did mic them and they are the same diameter As the frosty ones. But mic-ing them doesn't tell me whether the micro grooves are deeper.

[SP101GUY]

+1 on the optical illusion. The first time I cast about a hundred 310g Lee's, I pulled them out of the water bucket. They were all frosted and looked like they didn't fill out at all. I was hotter than the mold at that point.

Then I put my contacts in and even got out the magnifier. They all filled out and measured perfectly, they just didn't look like it from a distance. They all shoot good too.

AJ

[runfiverun]

i have some steel molds that i just have to go slower with.
they will come out white on parts of the boolit and they will be rounded off.
my solution to these two molds is to fill differently add some tin and wait for the sprue to suck in and change color.
i've tried cleaning the vent lines, loosening the sprue plates etc...
it's just a time thing,and they are only happy in that temp zone.
they come out a iron grey color not really shiny not frosted.
it's just those molds happy spot.
kind of nice though as i can let them hang out on the pot cover and pour into them as i run another mold and make some as i go along.

[bigboredad]

I think you are seeing a optical illusion as well I have a lee mold that is a tumble lube design and when the bullets are frosty it can take a double look but from my experience they are the same as the shiny ones

[AZ-Stew]

When most of a boolit is shiny and only a small part of it is frosty, there is likely a difference in diameter (smaller) at the location of the partial frost. I don't have to measure it with a tool, all I have to do is run it through the lubrisizer. At the location of the frost, there will be lube across the driving bands, as well as in the lube groove, showing clearly that the driving bands are smaller in diameter at that location.

Dull gray works with some moulds, but trying to drive all boolits into full crystallization is a waste of heat, in my opinion. In addition, with pure lead for muzzle-odors (a new Cast Boolits word) or pure linotype, VERY shiny boolits will be produced at any reasonable temperature that causes complete fillout of the mould. With lino, that can be a pretty low temperature. Why drive your pot to 900+ when 600 will fill the cavity?

It's NOT cosmetics, it's alloy vs temperature vs fillout. When the mould completely fills, more heat only wastes electricity.

Regards,

Stew

[stubshaft]

That may be true on TL boolits. But I have had the "frosted" sections of some boolits measure a smaller diamter than when they are not frosted. I noticed this whan casting .502" boolits with a Lee 440gr mould. Fillout looked good but when I went to size I noticed that the bands that were frosted had minimal contact with the sizing die. I pulled a couple of boolits and measured them and found that the frosted section was as much as .0018" smaller in diameter.

[AZ-Stew]

Stub,

You and I are on the same page on this one.

Regards,

Stew

[Bret4207]

It's NOT cosmetics, it's alloy vs temperature vs fillout. When the mould completely fills, more heat only wastes electricity.

Regards,

Stew

A good point. But those of us with alloys a bit low in tin have to run the mould a little hotter to get good fillout. If it frosts, I don't care as long as the fillout and dimensions are right.

Hindsight being 20/20, I sure wish I'd latched onto all th e"printers lead" I passed up back in the late 70's.:groner:

[AZ-Stew]

A good point. But those of us with alloys a bit low in tin have to run the mould a little hotter to get good fillout. If it frosts, I don't care as long as the fillout and dimensions are right.

Hindsight being 20/20, I sure wish I'd latched onto all the "printers lead" I passed up back in the late 70's.:groner:

Bret,

Agreed. When I cast straight WW or WW with a bit of tin added, I do have to run the pot/mould a bit hotter to get good fillout, resulting in "dull gray" boolits, but I try to avoid full frost because it takes too long for them to cool before I can drop them from the mould. In addition, a long, skinny rifle boolit may still be soft when dropped if the system is run too hot, resulting in bent boolits, even when cushioned by a towel.

I run just enough heat to get the mould to fill. I don't see any need for more. And I've never had a problem with lube sticking to the boolits, even when they're shiny. I've always used 50/50, which is plenty sticky.

I've purchased enough lino and mono to last me for many years. I used to shoot the stuff straight out of magnum handguns, but I've learned the folly of that practice. I wish I had even half of it back.

Regards,

Stew

[Frank46]

When I first started casting all i was looking for was nice filled out bullets. Unfortunately a lot of then were anything but. Read an article I believe it was the CBA Fouling shot. OK tried hotter pot temps. Bingo got much better fillout fewer rejects and the bullets were pretty consistent in weight as well. This is from bullets like the 314299 up to the big lyman 45 cal rifle bullet much better all the way around.
Once all the bullets started coming out completely frosted I had to pick up my casting rate. Thats where the welders gloves come in handy. Fill the mold do a quick count to ten grab the sprueplate with a gloved hand turn mold sideways and out came the bullets. So after that day I cast frosty.Frank

[tactikel]

As long as my "frosty boolits" have nice shiney sides after going thru my Lee push thru who cares? They have filled out the mold and are sized to specs. I too use 2 and sometimes 3 Lee molds to keep the molds cool- I cast really fast (gotta lay off the coffee!!).:coffee:

[Ricochet]

My water dropped boolits drop frosty and stay that way.
I think the reason mine don't frost is that I cast them in a hot mould, cut the sprue and drop them as soon as the sprue will cut cleanly. They don't have time for any crystallization to occur before they get quenched.

[Bret4207]

Your pot only needs to be run as hot as you need to maintain a proper mould temp at your preferred casting rate. The more often the mould is filled with molten alloy and the less time it spends empty the warmer it will stay. If your casting tempo is slower or you let the mould sit empty longer it requires more pot heat to help make up for that.