Oxide Wash Application

[OlgaBiff]

Hi!

How do I apply washes to enhance the look of a glaze? Could you recommend any good online tutorial or have any tips to share?

 

For what I have read this world be a possible process:

·Bisque fire the piece

·Apply the oxide wash with a brush or sponge and wipe off excess

·Let dry one day (or longer if needed)

·Glaze as usual

 

Could also be done on top of the glaze? Would not the glaze be "washed away"?

Thank you so much!

[oldlady]

you are thinking too hard about this.  apply the wash, whether colored with oxide or stains just as you describe.   drying does not necessarily take a whole day.   

yes, applying a wash over an unfired glaze will wash off the glaze.   and just to be sure you are not imagining something, you cannot put a wash over a FIRED glaze.

[liambesaw]

You can put a wash on top of unfired glaze, Simon Leach does this with all his decoration

[OlgaBiff]

Thank you both. I was thinking to apply a manganese wash over a commercial black matte glaze to try to get some more visual interesting surface.

But I wonder how to apply the wash on top of the unfired glazed pot... Maybe spray?

[Bill Kielb]

1 hour ago, OlgaBiff said:

Thank you both. I was thinking to apply a manganese wash over a commercial black matte glaze to try to get some more visual interesting surface.

But I wonder how to apply the wash on top of the unfired glazed pot... Maybe spray?

Careful with the manganese it has specific handling risks and for sure breathing risks. Familiarize yourself with safely handling.

[Min]

Be careful when firing manganese, fumes from the kiln pose risk if the kiln isn't well vented. MnO and MnO2, are both insoluble in water and therefore  cannot be absorbed through the skin, however the kiln fumes can enter the lungs and bloodstream through mucus membranes.

[Bill Kielb]

5 hours ago, Min said:

Be careful when firing manganese, fumes from the kiln pose risk if the kiln isn't well vented. MnO and MnO2, are both insoluble in water and therefore  cannot be absorbed through the skin, however the kiln fumes can enter the lungs and bloodstream through mucus membranes.

Fumes are an issue but manganese can be absorbed multiple ways and your body can not immediately remove it.  So kiln firing, some through the skin,  and inhalation are all known pathways. Read the dangers from a .gov source,  become as informed  as practical and try to avoid. Failure to do so can pose a significant health risk.

[Min]

5 hours ago, Bill Kielb said:

 some through the skin,  and inhalation are all known pathways.

Page 9 , from Willam Carty, professor of ceramic engineering and materials science at Alfred University. "An example of ceramic glaze (and body) folklore are the reports surrounding the use of manganese (Mn) and its link to Parkinson’s Disease. Mn in a soluble form is a neurotoxin, but this data was generated from the steel industry and the conditions of exposure are dramatically different due to the vaporization of Mn during steel production (and the use of a furnace open to the local environment, that is, without a stack). Inhalation of these vapors creates a readily available reactive species for adverse interactions with the body (and internally through the lungs and mucus membranes). Even small amounts can be readily absorbed into the bloodstream. The oxides of manganese, MnO and MnO2, are both insoluble in water and do not pose a threat. The Mn is not soluble and therefore not available, cannot be absorbed through the skin or even an open cut, and even if ingested, cannot dissolve into the blood stream."

Absolutely agree with you though, practice good studio hygiene to minimize risks with all the materials we use.

 

[Bill Kielb]

On 11/29/2019 at 11:25 PM, Min said:

Page 9 , from Willam Carty, professor of ceramic engineering and materials science at Alfred University. "An example of ceramic glaze (and body) folklore are the reports surrounding the use of manganese (Mn) and its link to Parkinson’s Disease. Mn in a soluble form is a neurotoxin, but this data was generated from the steel industry and the conditions of exposure are dramatically different due to the vaporization of Mn during steel production (and the use of a furnace open to the local environment, that is, without a stack). Inhalation of these vapors creates a readily available reactive species for adverse interactions with the body (and internally through the lungs and mucus membranes). Even small amounts can be readily absorbed into the bloodstream. The oxides of manganese, MnO and MnO2, are both insoluble in water and do not pose a threat. The Mn is not soluble and therefore not available, cannot be absorbed through the skin or even an open cut, and even if ingested, cannot dissolve into the blood stream."

Absolutely agree with you though, practice good studio hygiene to minimize risks with all the materials we use.

 

Maybe,

current docs from ATSDR say it’s an issue. My suggestion since it can be cumulative and cannot be readily expelled  from the human body use all practical precautions including contact with your skin. ATSDR says can be absorbed slightly directly through dermis so I would not dismiss it.  Definitely don’t ingest it or breath it for sure. Safety first would be my motto, artists have a track record of licking their brushes.

https://www.atsdr.cdc.gov/phs/phs.asp?id=100&tid=23

 

 

[liambesaw]

I've seen like 20 different MSDS and SDS for MnO2 and the ones that are more specific mention that it's 80% or higher manganese dioxide, and mention manganese salts as well.  I'm going to go ahead and guess that in addition to manganese dioxide there are other manganese salts and oxides as well.  

[Min]

1 hour ago, liambesaw said:

I've seen like 20 different MSDS and SDS for MnO2 and the ones that are more specific mention that it's 80% or higher manganese dioxide, and mention manganese salts as well.  I'm going to go ahead and guess that in addition to manganese dioxide there are other manganese salts and oxides as well.  

I agree, you need to look at the form the manganese is in. In the OP's post when she mentions perhaps using a manganese wash for all intents and purposes this would be made from manganese dioxide or manganese carbonate and those are the forms of manganese referenced in the quote from Dr Carty above. Manganese salts are a whole other issue just as the supplement forms of manganese such as manganese gluconate, sulfate, ascorbate etc. Apples and oranges.

edit: time to move this into a new thread so we don't digress too much from the OP's original question. thanks

[liambesaw]

4 minutes ago, Min said:

I agree, you need to look at the form the manganese is in. In the OP's post when she mentions perhaps using a manganese wash for all intents and purposes this would be made from manganese dioxide or manganese carbonate and those are the forms of manganese referenced in the quote from Dr Carty above. Manganese salts are a whole other issue just as the supplement forms of manganese such as manganese gluconate, sulfate, ascorbate etc. Apples and oranges.

edit: time to move this into a new thread so we don't digress too much from the OP's original question. thanks

I meant that since MnO2 that we buy is impure (80%+), that some of those impurities are other oxides of manganese (which are soluble) and possibly salts as well.  Anyway, I agree, this isn't the thread to discuss it in.