Authur Posted January 8, 2019 Report Share Posted January 8, 2019 I m very new to glazing. I have done few glazing color but couldn't able to get clear white like coffee cups as shown in figure. My cups turn out coconut milk color or white grey instead of perfect white. Link to comment Share on other sites More sharing options...
liambesaw Posted January 8, 2019 Report Share Posted January 8, 2019 Zircopax is a colorant that is a blinding white. Link to comment Share on other sites More sharing options...
Callie Beller Diesel Posted January 8, 2019 Report Share Posted January 8, 2019 What clay are you using? What glazes? There's about a million reasons this could be happening, and specific materials will help us troubleshoot properly. Link to comment Share on other sites More sharing options...
neilestrick Posted January 8, 2019 Report Share Posted January 8, 2019 If you're working with a brown or red clay, white can be more difficult. It's easiest to start with a white clay body, and use a white glaze over it. Any clear glaze can be made white by the addition of a zircon opacifier such as Zircopax or Superpax. You'll need 10-12% to get a solid bright white. The base glaze formula will affect just how the white looks, but this will be a good starting point. Link to comment Share on other sites More sharing options...
Authur Posted January 9, 2019 Author Report Share Posted January 9, 2019 Thanks for replies guys. It help alot. The one i using is I bought from local seller here. I think it is called "earthenware" ? I also attached color of my clay also. I am new to this glazing things. I m gonna try out more with zircopax. Link to comment Share on other sites More sharing options...
neilestrick Posted January 9, 2019 Report Share Posted January 9, 2019 You can definitely get a good white on earthenware/terra cotta if you opacify the glaze enough, although maybe not the bright white like in your photo. Majolica was traditionally done on terra cotta, and it's pretty white, but not like it would be on a white clay. If you're using commercial glazes, they may or may not be white enough to work well on red clay. Link to comment Share on other sites More sharing options...
Callie Beller Diesel Posted January 9, 2019 Report Share Posted January 9, 2019 You will have to heavily opacify any glaze that you want to be that brilliant white over a red clay, and zircopax will indeed be your friend. If you want something to be that really pristine white with no hint of a shadow, even switching to a white earthenware will help that process along. Personally, I work with a lot of white glaze over red clay because I like that shadow, and the contrast it brings. It's just a different aesthetic choice. Link to comment Share on other sites More sharing options...
Min Posted January 9, 2019 Report Share Posted January 9, 2019 If you really like your red clay and don't want to switch to a white clay you can also cover the red clay with a white slip. One way of how to do that on mugs here. It's an extra step and the timing on when to apply the slip is important but it's another option. Covering glaze wouldn't need as much zircopax going over a white slip (or clay) than a red one. Link to comment Share on other sites More sharing options...
Bill Kielb Posted January 9, 2019 Report Share Posted January 9, 2019 Zircopax is an opacifier in that it blocks light or hopefully reflects all light. While effective, dark clay will require 100% opacity to appear 100% white. This will be difficult to do attempting to match the cup in your picture exactly using a dark claybody. In addition minor contaminants gettting into the glaze will often show up as an annoying speckle or two. Using a lighter claybody along with a fairly pure white gloss glaze is likely the only way to match the cup in the picture fairly closely. Tin and zircopax traditionally have been the colorants used to get white. Zircopax is cheaper these days but also does not melt (by design) and tends to cutlery mark. Link to comment Share on other sites More sharing options...
liambesaw Posted January 9, 2019 Report Share Posted January 9, 2019 Tin is also not a bright white, it's warmer than zircopax. I think tin looks nicer on dark clay bodies, but it's very expensive so I use a combination of zircopax and titanium to soften the white. Link to comment Share on other sites More sharing options...
liambesaw Posted January 9, 2019 Report Share Posted January 9, 2019 This is what the mixture looks like, a bit softer like tin Link to comment Share on other sites More sharing options...
Bill Kielb Posted January 9, 2019 Report Share Posted January 9, 2019 Nice decoration! I like the softer look as well and the variation. Stark white is not my choice and screams production to me. Just my aesthetic preference though. The bare bones simple coffee cup does look good though so I can se how it would be desireable. Link to comment Share on other sites More sharing options...
Babs Posted January 9, 2019 Report Share Posted January 9, 2019 Liam what percentages of titanium and zircopax are you using? What colour of clay are you usi gng? Link to comment Share on other sites More sharing options...
liambesaw Posted January 9, 2019 Report Share Posted January 9, 2019 48 minutes ago, Babs said: Liam what percentages of titanium and zircopax are you using? What colour of clay are you usi gng? I think that one was 10% zircopax 2% titanium dioxide in hansen 20x5. I use Klamath yellow from Seattle pottery supply, it's a yellow cone 6 stoneware that fires red in oxidation, dark brown in reduction. Piece was fired in reduction (you can see the iron spots). Link to comment Share on other sites More sharing options...
Babs Posted January 9, 2019 Report Share Posted January 9, 2019 Nice piece. The softerwhites certainly more attractive to me. Tin still my favourite but add or cut it with zirc nowadays. Wonder if your mix is more fluid though depends on vlaze I guess Link to comment Share on other sites More sharing options...
liambesaw Posted January 9, 2019 Report Share Posted January 9, 2019 2 minutes ago, Babs said: Nice piece. The softerwhites certainly more attractive to me. Tin still my favourite but add or cut it with zirc nowadays. Wonder if your mix is more fluid though depends on vlaze I guess Yeah hard to know, gotta test test test! I can't even count how many times I've seen a nice glaze, tried the recipe, and ended up with something way different. A little different is something I can understand, but WAY different is sad. Especially when you put a bunch of tin into something, that stuff is like gold Link to comment Share on other sites More sharing options...
Babs Posted January 10, 2019 Report Share Posted January 10, 2019 But as a potter you know when tin is doing it! Link to comment Share on other sites More sharing options...
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