Here’s the newest round of slips for leather hard/stiff application. All but #7 will work for bone dry application. Not tested (yet) for bisque application. Fired to cone 10 flat in a hard reduction. Left side is super thick, right side is thinner. Clay body is a Hawthorn/Goldart/OM4 stoneware – nothing fancy.
#1 Greenware Slip: Grolleg Kaolin 40, OM4 Ball Clay 10, Custer 25, Silica 25
#2 Greenware Slip v.1: EPK 25, Grolleg 25, OM4 Ball Clay 10, Custer 25 Silica 25
#3 Bringle Slip: EPK 20, OM4 20, Neph. Sye. 25, Silica 30
#4 BS v.1: Grolleg 25, OM4 25, Neph. Sye. 25, Silica 25
#5 BS v.2: Grolleg 30, OM4 10, Neph Sye 20, Silica 20
#6 Coleman Clay: EPK 50, Silica 25, Custer 25, Frit 3110 5
#7 CC v.1: Grolleg 50, Silica 25, Custer 25, Frit 3110 5
#8 Porcelain Slip: Grolleg 30, OM4 8, Custer 30, Silica 30, Bentonite 2
The light is cheating these a little bit. #1,2, and 8 seem to be the whitest, with not much differentiating them. #1 seems to promote the best celadon blues, although timing is critical, because it cracked when applied to a bone dry tile. #2 seems to be a perfect middle ground in terms of versatility, cost, and whiteness. In my experience, the difference between a 50/50 grolleg/epk and a 100% grolleg clay body is negligible in cone 10 reduction. The case could be made that it really matters in oxidation – which is just now bringing to mind the need to test these in c6 oxidation.
My picks? For Whiteness:
#2__Greenware Slip___
EPK 25, Grolleg 25, OM4 10, Custer 25, Silica 25, 45cc Water, 5cc Darvan #7,
For Celadon Blue:
#8__Porcelain Slip___
Grolleg 30, OM4 8, Custer 30, Silica 30, Bentonite 2, 50cc Water, 5cc Darvan #7
