Porcelain lids

[PotterPutter]

Hi all! I usually work with stoneware, but have switched to porcelain for a while. I’d like to make some lidded vessels but I’m concerned about the lids sticking. They stick on my stoneware pots, but a tap on a table usually pops them right off. 

I’ve read that sticking is more likely when firing porcelain vessels with the lid in place. Any tips on preventing/minimizing this? I use Forbes wax resist - is this enough or do I need to use/add alumina and if so, how to I do that? Can I add it to the wax, or mix with water and brush on top of the wax? 

Thanks! 

[Jend3]

Yes, add some alumina to wax.  It is good to use on the feet of your porcelain pots  during firing and you wont get any of those little chips in the foot ring. 

[Min]

A heaping teaspoon of alumina hydrate to roughly a cup of wax resist. Keep mixing it up while you use it as the alumina will settle out. I would add a few drops of food colouring also, make the alumina wax resist a different colour than your normal wax so you don't mix them up. 

[PotterPutter]

1 hour ago, Jend3 said:

Yes, add some alumina to wax.  It is good to use on the feet of your porcelain pots  during firing and you wont get any of those little chips in the foot ring. 

Thank you! Most of my pots have flat bottoms, so that’s a lot of surface area to worry about.  Great tip. I wouldn’t have thought of that. 

[PotterPutter]

28 minutes ago, Min said:

A heaping teaspoon of alumina hydrate to roughly a cup of wax resist. Keep mixing it up while you use it as the alumina will settle out. I would add a few drops of food colouring also, make the alumina wax resist a different colour than your normal wax so you don't mix them up. 

I’m a label-maker junkie, but can see myself ignoring the label. Making it a different color is a great idea.  Thank you!!