Corrosion on Lee and Lyman ingot mold.

[Jaak]

I stopped casting for a couple of years and put away all of my equipment in an unheated shed (except for the bullet molds). When I dug out the ingot molds I saw a thick white corrosion all over both the Lee and the Lyman molds. Anybody know what this is? I tried to sand it off with a few wipes of some sand paper but it's only getting some off it off. Any tips on how to recover my ingot molds or do I just throw these away and get new ones?

https://imgur.com/a/Xo7T8

[Motor]

It's oxidized aluminium or aluminium rust if you will. Don't worry there are ways to remove it but there will be pitting under it. I'm sorry but I can't think of what's best to remove it off hand other than dry blasting (basically sand blasting). Hang in there someone will post with a cleaner or something that dissolves it.

Motor

[Jniedbalski]

They make a product called aluminum jelly. It will get the oxidation off but why. Just cast ingots like the molds are they will come out easy and it won't hurt anything

[country gent]

Don't know of a solvent to remove it. A wire brush and some elbow grease will remove it One of the tooth brush sized brushes with steel bristles, the brass ones may also work. The problem with sandpaper or scrath pads is the powder / corrosion plugs them up and affects how well they cut. The wire brush will move it and stay cutting. Sand Blasting the surface will work. If you have a larger case polisher a trip thru it may remove it also. walnut would be good then corn cobs. Rice or wheat grains may also work faster.

[Bazoo]

A 1 inch end brush in a drill will make short work of it. I've cleaned mine like this. I've also used it to clean the inside of my lyman dipper occasionally.

[Jaak]

All right then. Thanks for the info guys. I have a buddy with a sand blasters on the other side of town. I'll see when I can steal a few minutes from him one day.

[tazman]

They make a product called aluminum jelly. It will get the oxidation off but why. Just cast ingots like the molds are they will come out easy and it won't hurt anything

What he said. It doesn't effect the usability of the ingot mold at all. Mine did that after my basement flooded. I just used them as normal.
Best to heat them up some the first use. There may be a tiny bit of moisture in the oxidation causing a visit from the tinsel fairy if you don't.

[lightman]

Be careful with the sand blaster, they can cut aluminum. A bead blaster may be better.