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Project Name Campana Clear Cone 6 Adjustment Project Project Codenumber UnAssigned Notes This project is attempting to find a middle fire clear that has a lower expansion than G3806C (one that we have been using and recommending starting in 2016). 3806C does not pass the 300F:IceWater test on P300. |
Campana Cone 6 Transparent Glaze 3134, Spodumene, Zinc
Total:100.00 Auto Unity Formula
Notes *This is a popular fluid-melt cone 6 base recipe. We first compared it with 4 others in an effort to produce a fluid-melt, super-gloss, low-expansion transparent base. This appears to be the 20x5 recipe with Custer feldspar switched for a mix of zinc and spodumene (combining the power of lithia, zinc and boron fluxes to achieve a very low calculated thermal expansion, it does not craze on any of the bodies tested). Interestingly, because it has lots of melt fluidity it could likely accept more Al2O3 and SiO2 and yet still fire glossy (meaning the expansion could be taken still lower). Pictures Compared with G2926B ![]() These are 10 gram balls melted down onto a tile to demonstrate fluidity, clarity and bubbling. Left is our standard cone 6 glaze. Right: G2813. It is flowing significant more, but not as much more as some others I am testing right now. Bottom: G3813 on a Polar Ice porcelain tile. It is high glossy, not crazing out of the kiln. G3813 16x closeup of entrained bubbles ![]() Others also had bubbles, but there are alot here. And they are all the same size (in clouds). Although the photo does not show it clearly, hundreds of these are breaking at the surface, leaving dimples. This was fired by drop-100F-an-soak. This would do better in clearing itself with thinner application. G3814 Low Zinc High Feldspar Fritless base melt balls ![]() Top: G3814 G2926B Plainsman whiteware base L3808A high B2O3 fluid clear G3813 Campana clear Fluid cone 6 clear glazes ![]() These are 10 gram glaze balls are fired down onto tiles to demonstrate melt fluidity and bubbling. Left: L3808 GB clear from Shaun Mollonga (most fluid). G3808A fritted recalculation of former (best surface). G3813 Campana clear (most transparent). G3806B Panama Blue base. All of these survived 260F:Icewater test without crazing on M370, M390 and M340. Campana Clear is the smoothest on M340, Panama is second best. Campana clear on Plainsman M370,340,390 ![]() These were ice water tested at 260F and did not craze. Coverage is defect free on all three clays. Fluid cone 6 clear glaze comparison ![]() Top are 10 gram balls melted down onto a tile to demonstrate melt fluidity and bubble populations. Second row: Plainsman M370 whiteware Third row: Plainsman M340 buff stoneware Fourth row: Plainsman M390 red stoneware Left to right: G3814 - not melting as well G2938 - Water blue base G3808 - High Gerstley Borate base G3808A - 3808 using frits instead G3813 - Campana base G3806B - Panama base Cone 6 High Fluid Melt Transparents ![]() The chemistry of these glazes falls outside typical cone 6 boron, soda, calcia, magnesia chemistry. Why? To achieve higher melt fluidity for a more brilliant surface and for more reactive response with colorant and variegator additions. Classified by most active fluxes they are: G3814 - Moderate zinc, no boron G2938 - High-soda+lithia+strontium G3808 - High boron+soda (Gerstley Borate based) G3808A - 3808 chemistry sourced from frits G3813 - Boron+zinc+lithia G3806B - Soda+zinc+strontium+boron (mixed oxide effect) Compare four clear bases for copper blue ![]() Has extenal picture also The flow testers at the back and the melt-down-balls in from of them have 1% copper carbonate. The glazed samples in the front row have 2% copper carbonate. L3806B, an improvement on the Panama Blue recipe, has the best color and the best compromize of flow and bubble clearing ability. XML (to paste into Insight) <?xml version="1.0"?> <recipes version="1.0" encoding="UTF-8"> <recipe name="Campana Cone 6 Transparent Glaze" keywords="3134, Spodumene, Zinc" id="75226" key="SuWbGcvh" date="2018-03-19" codenum="G3813" email="strawdogs@hotmail.com"> <recipelines> <recipeline material="Spodumene" amount="11.000"/> <recipeline material="Ferro Frit 3134" amount="21.000"/> <recipeline material="EP Kaolin" amount="20.000"/> <recipeline material="Silica" amount="20.000"/> <recipeline material="Wollastonite" amount="20.000"/> <recipeline material="Zinc Oxide" amount="8.000"/> </recipelines> </recipe> </recipes> Born: 2015-06-23, Modified: 2018-03-19 15:58:30 |
Campana Clear Lower Expansion #2 3134, Spodumene, Zinc
Total:110.00 Auto Unity Formula
Notes *This recipe is the product of an ongoing search to find cone 6 low expansion ultra glossy clear glazes. P300 is the most difficult cone 6 body we have at Plainsman for fitting glazes. Our standard G2926B will fire uncrazed, but the combination fails a 300F:IceWater test (the way we evaluate long term resistance to crazing). Our G3806C recipe does the same. This recipe survives the test. Pictures G3813B Campana Clear mugs ![]() Fires super glossy, looks good. But there are entrained bubbles (top) vs. no bubbles in 2926B one below. 2926B vs G3813B clear glaze melt balls ![]() Crazing on the inside upper of P300 mug after a week ![]() This did not happen on P6476 Pioneer P300. G2926B vs G3813 B, C, D ![]() B top right, C - bottom left, D - bottom right. The added silica and MgO in the D make it appear more opaque yet on a mug it is crystal clear. D is moving toward the appearance of 2926B Whiteware (top left) but is still more fluid. Perhaps it could host a reactive result like floating blue. XML (to paste into Insight) <?xml version="1.0"?> <recipes version="1.0" encoding="UTF-8"> <recipe name="Campana Clear Lower Expansion #2" keywords="3134, Spodumene, Zinc" id="95906" key="KSX3RnLG" date="2016-11-19" codenum="G3813B" email="strawdogs@hotmail.com"> <recipelines> <recipeline material="Spodumene" amount="11.000"/> <recipeline material="Ferro Frit 3134" amount="21.000"/> <recipeline material="EP Kaolin" amount="20.000"/> <recipeline material="Silica" amount="30.000"/> <recipeline material="Wollastonite" amount="20.000"/> <recipeline material="Zinc Oxide" amount="8.000"/> </recipelines> </recipe> </recipes> Born: 2015-06-23, Modified: 2016-11-19 11:26:15 |
Campana Clear Low Expansion (no Spodumene) 3134, Spodumene, Zinc
Total:122.50 Auto Unity Formula
Notes *This sources Li2O from a Fusion Frit instead of Spodumene. This is a strategy to remove the micro-bubbles in the fired glass (and tiny dimples on the surface). Pictures G3813C Campana Clear Low Expansion (no Spodumene) ![]() G2926B vs G3813 B, C, D ![]() B top right, C - bottom left, D - bottom right. The added silica and MgO in the D make it appear more opaque yet on a mug it is crystal clear. D is moving toward the appearance of 2926B Whiteware (top left) but is still more fluid. Perhaps it could host a reactive result like floating blue. G3813C glaze on inside of P300 mug ![]() Bottom is a little matte, as well as sides (because of clouds of micro bubbles). Just below the rim it is glossy. Survives 300F:Icewater test. XML (to paste into Insight) <?xml version="1.0"?> <recipes version="1.0" encoding="UTF-8"> <recipe name="Campana Clear Low Expansion (no Spodumene)" keywords="3134, Spodumene, Zinc" id="99421" key="1eBXpCDR" date="2016-12-02" codenum="G3813C" email="strawdogs@hotmail.com"> <recipelines> <recipeline material="Fusion Frit F-493" amount="9.000"/> <recipeline material="Ferro Frit 3195" amount="18.000"/> <recipeline material="EP Kaolin" amount="25.000"/> <recipeline material="Silica" amount="34.500"/> <recipeline material="Wollastonite" amount="27.000"/> <recipeline material="Zinc Oxide" amount="9.000"/> </recipelines> </recipe> </recipes> Born: 2015-06-23, Modified: 2016-12-02 11:48:21 |