Jump to content

How can i make this glaze “whiter”?


Recommended Posts

1 hour ago, Crooked Lawyer Potter said:
VC Matte Base
Custer feldspar.  40
Whiting.  16
Silica.  16
EPK.   10
Frit 3124.   9
Talc.    9

@Dick White is spot on. Generally a base glaze contains no colorant and the end user colors to taste. This glaze is Val Cushings VC 71 I believe and there are folks who have noted some problems with some bodies. It’s chemistry would infer a gloss but it’s firing range is generally cone 5-6 so it would be interesting to see if it simply becomes a gloss as it’s fired cone 6 and beyond. If it did then that would infer it really is just an under-fired gloss at lower firing temperatures.

Here is a Glazy link from which you may be able to learn more, see some colorant or find variations should you have a need https://glazy.org/recipes/1373

Edited by Bill Kielb
Link to comment
Share on other sites

The VC 71 has been around for years and I've read many accounts of it being problematic. Spar is high for a cone 6 glaze, boron is low and it will fire to a gloss if taken higher, these all point to it being matte because it's an underfired higher fire glaze, not a properly formulated matte glaze for cone 6.  It's had a few alterations along with name changes over the years. With approx 3 copper carb + 5 rutile it became known as Xavier Warm Jade. Ron Roy altered the Xavier's Warm Jade recipe to be more durable when fired to cone 6 by decreasing the spar, increasing the boron and giving a slight bump to the silica. Much better glaze chemistry wise, it does fire to a gloss. Comparison of the two glazes below.

Obviously it's your choice to use it as is but if adding zircopax to it makes it even more underfired then reduce the silica content of the glaze by about 1/2 the zircopax content that you add. Between 8 - 12% zircopax should give you a solid white.

1928022069_ScreenShot2021-08-11at8_15_09PM.png.3aca039987699c21614eb24d47cfed17.png

 

Link to comment
Share on other sites

  • 2 weeks later...

If you want a whiter piece yet, use a clay without the speckling of the Manganese, or even more go for a white clay body. I love the speckling, some do not, and if wishing to do brush work or other decoration with under/overglazes use plain bodies.

 

best,

Pres

Link to comment
Share on other sites

Thanks. 

I usually do not like the big speckling but sometimes the plain white is a little drab.  So I have been using something I read about once:  steel wool, bisqued, then crumbled to dust and used as an additive to my glazes.  It produces a very nice -- and subtle -- effect that gives some depth and interest to otherwise plain jane surfaces.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.