Strange Ingot Issue ?

[pt4u2nv]

OK, Been lurking for quite awile trying to get a handle on casting my own boolits and finally secured a couple of buckets of WW's ( approx 145#) to try. I made a huge pot out of a 10" steel pipe with a 3/8" steel plate welded to the bottom for smelting on my turkey fryer stand and started melting my wheel weights down to make ingots. Pot worked great and tried to keep my temps in line as best as I could, between 600 and 700 degrees. Fluxed with pine sawdust about every 2 handfuls of WW's and melt looked great.....that is until I started pouring the ingots. They frosted worse than I have ever seen and actually some cracked in the middle and actually warped when I removed them from the ingot mold !! No idea what caused this or whether it will affect my bullet pouring so I thought I would check with all the pro's and maybe help me figure out what happened. I will say it was quite cold when I was doing the smelting and pouring of the ingots ( probably in the low to mid 30's)

I did skim off all the zinc weights and as I stated the melt in the pot looked great, no discoloration at all. I will try to post some pics tonight that may help to determine what went wrong.

I should also state that this affected all 110# of ingots I poured and made no difference from a cold mold vs a hot mold temp.

Any help in this new venture will be greaty appreciated

[Orygun]

Sounds like you didn't let the ingots cool long enough. You might try to find some more molds so you can let them cool longer between filling. Shouldn't be any problem with the alloy.

[dragonrider]

You are making ingots, nothing matters except the fluxing, using sawdust is the way to go.
frosting? ignore it, breaking apart and warping? ignore also. From your description you are doing excellent so far.

[pt4u2nv]

Sounds like you didn't let the ingots cool long enough. You might try to find some more molds so you can let them cool longer between filling. Shouldn't be any problem with the alloy.

Actually the frosting started as soon as the alloy started to cool, long before I released them from the mold. You may be right though with the cracking and warping being from releasing them too soon. I had to let them set for several minutes even at that for the mix to solidify enough to remove from the mold.

[pt4u2nv]

You are making ingots, nothing matters except the fluxing, using sawdust is the way to go.
frosting? ignore it, breaking apart and warping? ignore also. From your description you are doing excellent so far.

Will this frosting carry over to my boolits or is there something I should be doing to prevent this. I thought I should probably add some tin to the mix and maybe some pure Pb ???? I have about 750# of pure lead I thought I could use to make the WW's go a little farther.

By the way I am only planning on casting boolits for my 40, 9mm and 38, so I am assuming I do not need the boolits to be much harder than a BHN of about 10 - 14. Again this is all new to me so I will need some help understanding what I need for my applications.

I am fortunate in that I have access to an Alloy identity meter to check my alloy compositions. It records actual %'s of any given alloy. So far it has been a tremendous help as I add different alloys to my mix.

[454PB]

Wheelweights are usually in the 10 to 12 BHN hardness range. This should work fine for your applications.

No, the frosting is caused by the alloy and ingot being too hot. The boolits will only be frosted if the alloy and mould are too hot. Light frosting is a good thing.....it tells you your alloy is hot enough.

[lwknight]

Frosting is caused by slow cooling and nothing to do with melt temperature other than a high melt temp will heat up the mold and cause slow cooling. Cast into a thick cold mold and you get a shiny crome looking ingot.

[Hiaboo]

That happens to me, and nothing to worry about it all, here's a little interesting test -- as they cool, harden int he middle, give em a minute then just dump em out of the mold and whack em with a hammer and they will SHATTER!

Nothing to worry about.