Ravenscrag Plum Red Cone 6
Recipe
Notes
Iron red glazes are common, but tricky, in the cone 6 range. The red color is a product of iron silicate crystals forming during the cooling cycle in the kiln; it can be difficult to develop a process that gives repeatable results. Only a few people have discovered the proper combination of recipe, iron oxide percentage and firing curve (especially cooling). Warning: Iron Red recipes will confront you will troublesome or expensive materials (e.g. bone ash, tricalcium phosphate, lithium carbonate, gerstley borate, ulexite). Getting and using these will put your dedication to the test, especially when testing produces initial failures. Warning: High iron content causes glazes to gel, making application difficult. More water is needed to get fluidity, which causes higher drying shrinkage which leads to cracking during drying. Don't take this warning lightly, working with iron reds is working with "buckets of jelly" for glaze. Are you sure you want to do this? If yes, then this might be a good starting point. ====== While it would seem logical that these glazes should have a very fluid melt and a slow cooling cycle during firing to give the red iron crystals time to grow, in actual practice, we have not been able to confirm either assumption. However, it does appear that a thick application is needed to encourage the crystallization (thus there is a danger that too much thickness will result in it running down off the ware). Experience is needed to achieve a workable thickness to be able to manage vertical surfaces. Just try to apply the glaze just thick enough that you can tolerate the amount of running.
Description
Plainsman Cone 6 Ravenscrag Slip based iron-red glaze. It can be found among others at http://ravenscrag.com.