Sanding porcelain

[Nicky S 12]

Just to say .... bisque firing went well cups facing up and hardly any warpage Thankyou for imput

Am now preparing for glaze firing .I will only glaze the insides of cups I would like to get the satin smooth effect by sanding ( extra work but makes a diff in the feel ) Do I sand before or after glaze firing ??? Much appreciated Nicky

 

[Bill Kielb 807]

Probably easiest to sand  now and touch up  after firing as needed. It will be hard as a rock later. Glazing only the inside does present some risk of the cup shattering later due to the difference in tension created by a partially glazed body. Cups are particularly susceptible to this and you may want to glaze up and over the rim anyway just so folks don’t have to drink over an unglazed surface.  There are many satin matte glazes that could give you a similar look.

last thought: the glaze helps seal your mug from permeability so the more unglazed area means your clay hopefully is fully vitrified and not very absorbent once fully vitrified. (Fully fired to its rating)

hope that helps

 

[Nicky S 12]

@Bill Kielb Thank u for your input Had not thought about glazing over the rim ( that’s how new I am :-) ) And my first time glazing only the inside Tho admit still pondering if utterly necessary But  I could do half and half to see results Thank you 

 

 

[oldlady 2,579]

nicky, whatever you are thinking just add to it the possibility that nobody would want to drink from an unglazed cup.   the feeling on the lower lip would be discouraging to most people.

[Marcia Selsor 1,840]

If you want smooth surface by sanding bisque porcelain, you should try diamond pads with high # grit 800-1800. I think it is more simple to use a rubber rib when it is wet. You avoid clay dust which is bad to breath.

Marcia

[Nicky S 12]

@oldlady Admittedly my glazing skills have a looooong way to go yet Hadn’t realized how difficult it was I’m just trying to make some sample pieces But yes agree re rims Thank you Nicky

@Marcia Selsor As I’m using water etching technique unfortunately some spaces need to be sanded But def Agree should be avoided as much as possible esp as I have emphysema Thank you for info tho Nicky