Underglaze become dusty and fell off bine dry greenware

[Jinbei]

Hi! I'm a self taught artist, just starting out pottery.. soo i made a pottery mug and it's almost bonedry and i clean it up a bit then put an underglaze on it.

 

The underglaze kinda weird, it dries off as soon as it touch the greenwaee. But i keep applying until all covered up. 

 

Now it's been a week and the underglaze become dusty and fell of the greenware.. i planning on firing it next month(?) 

 

is it supposed to be like that? is it normal that the underglaze fall off like that? what am i supposed to do? 

 

[Babs]

Underglaze best applied to leatherhard greenware so your pot would have been too dry.

I apply at time of trimming foot, wipe all over with damp sponge then apply the underglaze. Can sgraffito at this point.

You can apply underglaze after bisque, wipe dust off and apply but may need to bisque again to avoid smudging when glazing.

Also the thickness of your underglaze before applying may be a factor.  

[neilestrick]

Is this an underglaze that you  made yourself, or a commercial underglaze that you purchased?