"skin" on my melt.

[Mpape]

New to casting boolits. I am using a quart cast iron pot over propane cooker. I'm
Getting a skin on top of the melted lead after dipping with the ladle a few times. I haven't fluxed, could this be my problem, or is it just slightly cooler on the surface?

This was for casting muzzle loader using pure lead.

[runfiverun]

it's lead oxide.
flat grey and wrinkly.
just push it away with the back of your dipper, then submerge.
knock it off the ladle occasionally.