Need help finding recipe

[CraftmanVN99]

Hello everyone,

I'm looking for a full recipe of emerald glaze for kaolin clay. I'm firing from cone 04-01. If anyone have a step-by-step tutorial or detailed recipe to create such color, please reply me. 

Thank you for your help!

[Min]

@CraftmanVN99, you have already had a few replies to your question about your search for an emerald glaze recipe in your other post about this so I don't want to duplicate what has already been said. It's difficult for us to give you an exact recipe as your materials and claybodies are going to differ from what most on this forum use plus we don't know what your ability to alter recipes to make use of your materials is. 

If you have a clear glaze that works for your clay and firing you could try adding the colourants Lisa Orr uses for her similarly coloured green glaze. In the image below the colourants Orr uses for her luscious dark green are chrome oxide 0.4 + copper carbonate 2.83 + Spanish Red Iron Oxide 9.43  

I doubt you have the materials for her base glaze but here is the recipe if you want it:

Lisa Orr Base Glaze cone 04

Gillespie Borate  9.43

Soda Ash  15.09 (very soluble material)

Ferro Frit  3110   63.21

EPK 4.72

Silica  7.44

Bentonite  1.89

 

 

 

[PeterH]

Looks rather like a low-fire lead glaze coloured by copper.  Their use by craft potters has largely been phased out on safety grounds (at least in those counties I'm most familiar with).

 

Are you familiar/happy with using lead glazes? Do you have a recipe for one?

PS This 1999 posting reflects the historic movement of craft potters away from the use of lead.
http://www.potters.org/subject22065.htm

PPS Digitalfire,  usually a comprehensive source of pottery information simply opts-out of giving advice on this topic.
Lead in Frits: The Hazards https://digitalfire.com/hazard/lead+in+frits%3A+the+hazards

Lead has been used in ceramics for thousands of years because it works so well, that is, leaded glazes melt at low temperatures, have low thermal expansion, dazzling colors and tolerance to variable firing. Frits are a modern development that have dramatically improved the safety with which the material can be handled. Notwithstanding this, leaded frits are difficult to obtain in recent years.

Generally most leaded frits were thought be fairly insoluble and safe to use as raw powdered materials, however recent findings about the disproportionately large effects of low lead levels call this into question. In addition, the glazes they produce will be as leachable for a given lead percentage as if the lead came from raw lead carbonate or lead oxide. There is a huge range of lead content in frits, some may have 1%, others 80%. To create a safe leaded glaze you need equipment to measure leaching of lead and expertise in ceramic chemistry to find the oxide profiles that release the least amount of lead.

Therefore we are no describing any safer ways to use lead here. Please check the reference links on this page.