Why did my mold dis-color?

[selmerfan]

I traded justingrosche for a nice NEI 178gr. .30 caliber mold. I preheated the mold the first time, heated the pot, and ended up with wrinkled boolits. I had done nothing to prep the mold. So I decided to remove any trace oils in the cavities by boiling in water with Dawn dishsoap. Now the mold is discolored with a grayish/blackish color. But it drops beautiful boolits! Is the discoloration aluminum oxide?

[Beerd]

I think it has something to do with what's in your tap water; chlorine, minerals, etc.
I have had the same thing happen to me with all of my aluminum moulds. It doesn't seem to hurt anything so I keep boiling them clean.
..

[JonB_in_Glencoe]

I have only Boiled one aluminum mold.
it was a older Lee 6 cav groupbuy.

I think the original owner used case Lube as a
sprueplate lube and was burnt on.

I thought boiling it in water would make the burnt stuff easier to clean.
BUT, all that happened was I got the grayish/blackish staining on
all the machined surfaces of the mold...still has the burnt on lube stains too.

It casts just fine...it's just ugly...drat !
Jon

PS, i won't be boiling a aluminum mold again.

[MtGun44]

Probably aluminum oxide, looking on the bright side, if it is alum oxide it should be
a bit harder than bare aluminum, may act as a mold release, too.

I scrub with Comet and toothbrush to clean and deburr Lee aluminum molds. Might
remove your ugly color.

Bill

[selmerfan]

I thought about the Comet, but I just got done casting with it - perfect shiny boolits and they don't quite jump out of the mold, but pretty darned close.

[PacMan]

I boil all my alum. molds in dawn soap before using. I really think it helps bullet release and prefer the greyish color to the shinney alum. color.

[Doby45]

I boil all of my aluminum molds with Dawn also and none of mine are grey. Either way it will not hurt the mold..

[MtGun44]

My guess is that it is minerals and ph of the water, not the Dawn that does this, so it
will vary around the country.

Bill

[theperfessor]

I think MtGun44 is right on about local water conditions. I also think that the alloy of aluminum used for the mold is also a factor. I do remember the warning I've read on certain dishwasher detergents about the possibility of staining aluminum cookware. As others have said it's just cosmetic.

[selmerfan]

And the cosmetics of the boolits that drop from it are beautiful, so I won't worry too much about it!

[GLL]

I also boiled an NOE with DAWN and ended up with a really ugly mould !
Casts beautifully though ! :)

Jerry