Frosting?

[fiatmom]

I was casting a 405 gr boolit from a Lee mold. The first one came out wrinkled which showed it was to cold. The next 6 came out perfect, then they started to frost starting fron the nose. Was I casting to fast ? or was the leas to hot. I don't have a thermometer but turned up the heat untill the tin went into the alloy. I was using wood shavings for a flux.

[geargnasher]

First, understand that frosting of antimonial alloys is a result of the temperature of the mould, not the temperature of the alloy being poured into it. You regulate mould temperature by casting pace, more pours per minute will keep it hotter, or you can slow down and/or use a fan to run it cooler. Frost is the result of a hot mould, wrinkles are a sure thing when it's too cold. I'm going to suggest alloy be maintained at as cool a temperature as possible for good casting, it oxidizes excessively and can slow down your casting pace significantly if it's too hot.

When they start to frost, slow your pace and use a small fan blowing across your casting area to cool the mould.

Personally, I prefer to run the Lee moulds hot enough to get a nice, even, light, satin frost all over the boolits, I get better fillout and razor-sharp bands and bases that way. This would be hotter than you got yours when just the noses were starting to frost a bit.

Try a variety of things, cast fast until your boolits are frosty all over, slow down until they are half-and-half, and then all shiny again, just play with the speed and mould temperature until you find the technique you like.

Gear

[lwknight]

Perfectly stated Gear. I agree 100%.

[Three44s]

Agree with Gear!


Three 44s

[montana_charlie]

I don't have a thermometer but turned up the heat untill the tin went into the alloy.
I don't know what that sentence means.
CM

[1Shirt]

Gear hit it on the head. That said, I like some frosting (not excessive) particularly on small blts. Think it holds lube better. Just my opinion however.
1Shirt!:coffee:

[gray wolf]

Gee Wiz Gear--
You don't leave any room for us slow to the key board guy's--Ha,ha--
Well said and you covered the question well.

Sam

[44man]

I don't know what that sentence means.
CM
I had to do a double take on that too! :mrgreen:
Gear has the answer.

[geargnasher]

I don't know what that meant, either. Tin disappears instantly even in slushy ww metal at my house.

The truth is, without a thermometer of some kind, there really is no way to tell how hot the alloy is once it's fully molten, especially 20 minutes or an hour into a casting session. With the Lee pots can be perfect one minute, and ten minutes later it can be 150 degrees hotter.

Gear

[XWrench3]

try using two different molds at the same time. alternating between them. if you still get frosting, try three. i used to spray the mold with water mist from a sprayer, but i really can not think it will help the mold any by doing that. so i started using multiple molds, to keep me at an even pace. i am to impatient to sit and watch a mold cool!

[Lizard333]

I had an old timer tell me to dip the mold in a coffee can full of water momentarily. Works with my cast iron molds. I use too different molds and dip my mold, full with sprue and cavities full of lead so as to not worp the mould. Works pretty well.

[oscarflytyer]

I had an old timer tell me to dip the mold in a coffee can full of water momentarily. Works with my cast iron molds. I use too different molds and dip my mold, full with sprue and cavities full of lead so as to not worp the mould. Works pretty well.

I would be way afraid of warping a mold with a water dip.

OTOH - I have been known to keep a wet COTTON (NO synthetics!) T-shirt or rag handy to sit the base of the mold on for a couple quick seconds. Helps a lot if I get things a tad hot, and also speeds up the casting rhythm.

[Lizard333]

No warping to date. I only dip the mold in the water for just a second. Works well.

[1Shirt]

I used to dip with a single mold and never warped one. For a number of years, with sing and double cav molds, use two or three at the same time with the pot cranked up as high as it will go.
1Shirt!:coffee:

[fiatmom]

I was told that if the alloy is to cool , or if more cold metal is added the tin would come out of alloy and float to the top. I found a silvery clump of metal on top untill the alloy was up to temp., was this tin? I was also told frosting was bad. My bullets were perfect but lightly frosted, so I remelted them : ( .
Thanks for all of your help.
Nick

[HDS]

I was told a damp cotton rag was the best way to cool a block down if it got too hot.

[waksupi]

I was told that if the alloy is to cool , or if more cold metal is added the tin would come out of alloy and float to the top. I found a silvery clump of metal on top untill the alloy was up to temp., was this tin? I was also told frosting was bad. My bullets were perfect but lightly frosted, so I remelted them : ( .
Thanks for all of your help.
Nick

Stay away from whoever is telling you that stuff. They are an idiot.

[white eagle]

some put a great deal in the appearance of their boolits
I just could never see them ... after I pulled the trigger
tin will appear golden in the alloy color scheme
when your alloy gets to temp you will not have any sloshy alloy
UNLESS
you have zink in your mix bad,bad stuff

[brotherdarrell]

funny thing about frosted bullets. if you rub them with a cloth the frosting disappears and they look like any other bullet.

brotherdarrell

[geargnasher]

funny thing about frosted bullets. if you rub them with a cloth the frosting disappears and they look like any other bullet.

brotherdarrell

Light frost disappears when you wipe it with a rag, that's how I cast the vast majority of my boolits, with the mould temperature high enough to just barely get rid of the last few shiny areas. Easiest way for me to get complete fillout with a bottom-pour pot. With a ladle, I cast slower. contact-pour for slight pressure, and run a cooler mould so I get nice shiny boolits.

Heavy frosting makes the boolit look and feel like sandblasted aluminum, and the boolit is usually grossly undersized. That's from a mould that is seriously overheated, even with a fairly cool alloy being poured into it.

Gear