oxide look to boolits?

[oneokie]

Am getting what looks to be oxides on the surface of my boolits. Using a bottom pour pot. Using sawdust for flux, stiring with a wood stick.
Nothing seems to change. Do I need to empty the pot and clean it? Use a different flux? Boolit fillout is good. Weight is consistant.
What say ye?

[GabbyM]

Could that just be frost from to hot of mould or alloy?

[454PB]

I've seen this before with certain alloys. I don't know what it is, but it doesn't hurt anything. A good cleaning of the pour spout usually clears it up, if it bothers you.

[runfiverun]

not using any tin?

[oneokie]

I think 454PB hit on what is causing my problem as I noticed that the stream from the spout is erratic. Will empty the pot and give it a good cleaning.