Shiny to frosted

[michael m]

While casting today, this happened for the first time. My RCBS 2 cavity .408 mold has about 20 bullets cast and then, the bullets drop out normally but within 3 minutes or less they get frosty looking like gray and grainy looking as if they were overheated in casting.

I have produced frosted bullets on purpose, and they look frosted right out of the mold.

Any ideas? The metal is supposed to be wheel weights(thats what I paid for).

[btroj]

Mould temp.
Slow down a bit to let the mould cool a bit more between casts to keep a consistent mould temp.

Frosted is good, just keep them all the same level of frosted.

[s mac]

It seems to me that in cold ambient temps that frosting as you describe occurs, maybe due to a more rapid cooling?

[Wayne Smith]

It seems to me that in cold ambient temps that frosting as you describe occurs, maybe due to a more rapid cooling?

If that were true we'd see it on all water dropped boolits. I don't. Maybe specific to a particular speed of cooling??

[cajun shooter]

It's a direct sign of heat, either the lead in the pot or the heat of the mold. Your frosted bullets are very useable but as was stated by another member, keep it all the same.
Are you using a temp gauge? Are you allowing the mold to sit a few seconds before starting again?
If you are just starting out, and you don't have a lead thermometer, buy one from someone like Tru- Temp.
If you have the available funds to purchase another like mold, then do so. I've been casting since 1970 and using this method of using two molds as it allows just the correct amount of time between pours. You may also cast another type of bullet if you wish, I've always purchased two molds to cast my bullets for SASS shooting. I posted a thread on this subject about 4-5 years ago. You may want to do a search if you are interested in learning the process. If not allow some time for the mold to stay at the same temp. Later David

If you

[RobS]

Mold temp changed from the time you had shinny to the time you started to cast frosty. Either casting tempo and/or your pot is heating the alloy warmer as you continued on etc.

[bhn22]

Within 20 bullets? I'm assuming that you preheated the mould, and you may have overdone it a bit. Was the sprue really easy to break at the end? It sounds like an overly hot mould to me too.

[John Boy]

It's a direct sign of heat, either the lead in the pot or the heat of the mold
The one and only reason for frosted bullets

[michael m]

Thanks for input, I will try to slow it down a little.

[glockky]

Its just frosty from heat as other have said. I personally like a little frosty and don't start keeping bullets until I get in a rhythm and can keep the amount of frosting consistent.

I also notice that higher antimony alloys seem to give bullets a little more grainy and frosty look.

[prs]

I may have misread, or a ALL of youse guys did. I thought he was saying the product drops shinny and then over the next little bit of time the boolits develop a frosted surface. When I get frosty boolits, they are frosty from the get-go. Jest the way I likes 'em.

prs (Who sets his pace just slow enough to avoid smearing lead with the sprue plate.)

[1Shirt]

The advice from Btroj is sound. I like some frosting, but I also like consistency in appearance. Develop a rhythm that produces consistency.
1Shirt!

[geargnasher]

I may have misread, or a ALL of youse guys did. I thought he was saying the product drops shinny and then over the next little bit of time the boolits develop a frosted surface. When I get frosty boolits, they are frosty from the get-go. Jest the way I likes 'em.

prs (Who sets his pace just slow enough to avoid smearing lead with the sprue plate.)

I think everyone pretty much missed it. I see that a lot with WW and no added tin, they're bright satin coming out of a hot enough mould, then 2-3 minutes of sitting on the towel where they were dropped and they have an electro-galvanized look, kind of like WWII battleship camo, sort of faceted and splotchy like some corrugated roofing metal or flashing can have. Some just turn light, satin grey frost like a dust that will wipe off with a single twist of a dry rag and leave the bullet super-shiny. The galvanized look goes away with the addition of some tin, and if more tin is added, (2% or more) the bullets look like the dull side of aluminum foil.....but may have been quite shiny when first dumped out of the mould.

I don't worry about it, been observing this sheen-change thing for years. All I an figure is that certain constituents of the alloy are oxidizing on the surface of the bullet as it cools, and depending on the crystal or dendrite structure of the oxides, they reflect light differently.

Gear

[btroj]

Oops, I didn't read that right the first time.

Like Gear said, mine often change sheen over time. Has to do with the alloy.

Mine often change again if I heat treat them, depending on heat treat temp.

[Toymaker]

Temperature - either (or both) your mold is heating up on you or the lead is. Take a piece of flannel or shop rag, put a bullet in it and rub it around. The frosting will likely come off. If you see pitting in the bullet, recast them. If you see something that looks like a crystalline structure you're probably ok. If the bullet is nice and shiny you're good to go. If the frosting doesn't come off and it feels rough, recast them. If the frosting doesn't come off but it feels smooth, shoot em.

[jkcerda]

So frosty Boolits are gtg?

[btroj]

Oh heck yeah!
I want frosty. Tells me the mould is up to heat. Shiny bullets can be a sign of a cold mould and cold moulds don't give consistent bullets.

[MtGun44]

final crystal structure settling in as it cools and the atoms find their final resting places.

Bill

[retread]

Oh heck yeah!
I want frosty. Tells me the mould is up to heat. Shiny bullets can be a sign of a cold mould and cold moulds don't give consistent bullets.

+1 ^ When I start a session I preheat the mold but sometimes the temp is a bit low at the start (mold temp) and the boolits are nice and shiny but some are not filled out perfectly. Once they start filling out consistently a slight frosted look appears, at that point I am where I want to be. With a regular rhythm and a PID to hold consistent pot temperature they stay a that level of frost throughout the session .

[rsrocket1]

I would much rather have frosty boollets with good fill-out than shiny boolits that are on the verge of rounded corners or wrinkles.

[geargnasher]

I would much rather have frosty boollets with good fill-out than shiny boolits that are on the verge of rounded corners or wrinkles.

+1.

There is such thing as too frosted, though, when the surface looks sandblasted and rough, and the mould is so hot that the bullets are actually undersized. You have to really over-do the mould heat to get that, though. It's important to realize that the mould temperature causes "frost", not the temperature of the alloy you put in there. You can pour smokin' hot alloy into a cool mould and the bullets will still be shiny, rounded, and maybe even wrinkled, and you can pour alloy that's barely hot enough to be liquid into an over heated mould and get sandy boolit syndrome.

Gear

[Blanco]

I happen to have 1 Lee mold, I think a .45 TC single lube groove.
It is the only mold I have that will do what is described. They drop out of the mold looking great then get an oxidized look after a minute or so. I can have other molds on a hotplate ready to go and mold from the same pot and it will drop beautiful boolits. I can switch right back to the .45 TC and get frosted boolits again.
So in my case it seems to be a mold thing? nd the mold will do the same thing hot / cold hi lead temp / lo lead temp ...

It really doesn't bother me cause they get polyester jackets.

[michael m]

turn a Thanks again, to everyone for their experiences and advice. I do not know the tin content, but I have slowed down some and the shiny bullets now stop have after 5 mold fills, and the balance nice look real nice uniform gray. Thanks to everyone

[runfiverun]

Remember the difference between grey and frosted.
Grey well filled out is good.
Frosted is rounded edges and far past the grey stage.
most of my boolits come out grey, and if you look closely at them you can see all the details cut into the mold.
Shiny is just that shiny but without the detail unless the shine is from the use of tin.