Contaminated

[BlackandWhitedogpottery 2]

I pretty sure I have contamined my ^6 white glaze with specks of granular manganese or Speckled Buff.  Can I seive a glaze to remove contaminants like clay particles? Perhaps.. hoping.. 

 

Also. When using my white glaze on my ^6 stoneware, does anyone ever have a light green haze? Not like a copper carbonate painting haze but a tinge of light green that turns the bright white glaze into off-white. 

 

Thank You

[Bunnybaer 5]

Do you mean the powder to sieve? Of course you ca do it. If the spots are big enough you´ll be successful. Although -maybe it´s getting interesting if you leave it so or is it too much?

 

The problem with white getting green shined, yes I nknow that, too. Sometimes it happens on clay wich is colored like sand. Don´t know how it is called in english, we call it creme in german. or lederfarben. liek leather.

Then sometimes I have a light shine of green or yellow.

 

If I heat up the oven, push the temparture higher, then it´s gettin better. But the flood is horrable....

[Callie Beller Diesel 1,675]

Sieving will work only if the contaminant particles are larger than your sieve mesh. You might be able to remove some, but probably not all.

With the glaze, can you post a recipe, so we can help troubleshoot?

[Babs 890]

could be from fuming in your kiln from previous or current firings...

[GiselleNo5 486]

If you're not able to get rid of it, I would say add an ingredient to cause speckling and a bit of green or blue colorant, that way it's uniform and you don't have a batch of unusable glaze!

[GiselleNo5 486]

... *whispers* Can ... can you do that? 

[Tyler Miller 435]

could be from fuming in your kiln from previous or current firings...

 

What I was thinking.  Copper likes to fume.  

[MatthewV 259]

Adding cobalt carbonate is a way to "fix" a glaze bucket by making it blue instead of clear/white/other light color. About 1% should turn it a pleasant shade of blue. Cobalt oxide (0.2-1%) will make it a speckled blue which is pretty nice if the original recipe was white.

 

It is very unlikely you could sieve out an ingredient. The process will just mix everything in so the color is smooth instead of speckled. Rocks, bits of bisque and debris will be all that stays on the other side of the screen.