mold with color contamination

[claclana]

Hello!

 

I am using plaster molds usually with white clay but would like to switch to red clay ones in a while,

how could I avoid contaminating the white clay in future works?

 

I assume washing the mold will take for ever to dry!

should I do another sets of molds? mmmmmmm...

some suggestions?

THANKS!!

[Harry Potter]

I spoke with a mold maker this week about the same thing. They suggested that I make a couple of cast with slip or moist clay with the alternative clay and just plan on throwing the cast away. They said usually by the second cast most of the alternate clay has been removed and shouldn't stain the other color. Worth a try.

[Mark C.]

The iron will contaminate the castings for a few times then you will be fine-the molds will always have an iron look to them if its a red clay with high iron content but the casts will after a while be fine when you switch back. You will need to clean the tops of molds and any spills and equipment etc when done withy red clay.If you are just doing this in a few working molds consider making new ones just for iron clays.

Mark

[Lucille Oka]

Personally I wouldn't mind it. But there are a few things you can do you can try cleaning the molds with clean sponges and yes it will take the mold a little longer to dry. If this is really an issue for you, have several sets of molds and never throw out your molds for a little contamination. If needed use underglaze as a touch up.

[claclana]

Thank you!