Got Greedy, may need help

[moose30273]

Hey, Just scored a bunch of old fishing sinkers. Most are 30+ years old so I feel good about the lead in them. However, mixed in with the sinkers were several chunks of what appeared to be lead. So, I treated them like lead just throwing them into the mix when I smelted (wood fire cast iron pot, high tech) everything down. There was just a little moltin lead in the pot when I put these in. So as the metal began to heat back up these chunks became sorta crumbly. But then they melted and everything flowed properly. After the fact I have several muffin tin ingots that the top looks great but the bottom looks "galvanized". It appears to be made up of a patchwork of different blocks or squares of metal. Any Ideas? I figure I just got greedy and should have known better.

[xr650]

The crumbly may be that the lead melted slowly.
The galvanizied look may just be frosted.
Cast with some and see how it does.

Welcome to the site.

[Boerrancher]

I have noticed that larger chunks of lead will often as they start to melt will crumble and almost look like they are made of silver grains of sand stuck together. The galvanizing you are seeing is what we refer to as frost. There is nothing wrong with frost it just means that that part of your ingot was hotter and cooled at a different rate than the rest. I am not going to go into the complete cause of frost, as I will save that for some of our resident metallurgists to delve into that. I think you will be fine, just when you put it in your casting pot keep your temps low and if it does happen to be zinc it will float on top after the rest of the lead melts off of it. I hope this helps.

Best wishes from the Boer Ranch,

Joe

[Down South]

My ingots have a galvanized look on the bottom too. As stated above, It's just from the lead being hotter on the bottom of the ingot when poured and it's called frosted.

[moose30273]

Thanks Guys. I feel better. Probably 90% of my first cast bullets were frosted simply because if 650 degrees is good then 900 is better. There is a learning curve here. I have just never seen such a large example.

[jameslovesjammie]

If they looked like this they are completely normal.

http://i26.photobucket.com/albums/c129/jameslovesjammie/gun%20stuff/Casting%20Stuff/P1010944.jpg

I had similar concerns when I first started casting and was told here that it was no problem! The chunky and crumbly stuff was just lead that wasn't up to temperature. The broken ingot was caused by not allowing my mould to cool down enough before I dumped them.

[jameslovesjammie]

Here's a link to my original post.

http://www.castboolits.gunloads.com/showthread.php?t=33302