Glaze Pops On Slipcast Items

[Lorraine76]

Hi All!

 

I've been making these small water fonts and bottles. All items are slipcast from the same slip. The small fonts were perfect with the glaze. But i've just emptied the kiln and the bottles are awful. Did with the same glaze as the fonts - dipped, fired at the same temperature...

 

The bottles are full of glaze pops. I fired the the caps (wine stoppers) of the bottles too and they had no glaze pops. Only the bottles have these pops (with two different glazes)

 

Can you help me what can be the problem?

 

thanks in advance

 

Nandor

[Mark C.]

This does not look like glaze POPs more like dust or adhesion issues as in bubbles formed in glaze when dipped.

Was bisque ware clean (washed or blown off?) did the glaze bubble ever so slightly when dipped? was it to thick?

Mark

[bciskepottery]

The glaze may be too thick and is crawling; take a small container of the glaze, add one, or at most two, drops of Darvan, stir and glaze a test item.

[Lorraine76]

Bisque was blown off. It didnt seem thick (there are some areas on vase where it is rather thin). It had some bobbles after dipping, but not so many and it was "dusted off"

 

Would reifiring help? Or thinning glaze and washing off and not dusting off?

 

There are some other pieces that are already dipped but not fired. Should we dust them off and then fire for example on lower temp. and longer hold? Would that help?

 

Thanks

[Mark C.]

If the glaze has the bubbles on surface when dry- I would rub them out with my finger 1st before firing. 

Does the surface of the bucket of glaze have bubbles on it? or do they appear after dipping??

Usually if you rub them out when dry you have no more issues .

Or at least with the few bubbling glazes I use.

Mark