excessive manganese

[suetectic]

this Gold Metallic (No Redart) on glazy immediately strikes me as irresponsible

I'm wondering what more people feel about these toxic oxides getting used in high amounts to satisfy extended UMF glaze requirements?

Am I just a bit of a codger when I want to tell people just because you can doesn't mean you should?

[Min]

How I'm reading his comments are the recipe won't work without the manganese and copper as they are necessary to flux the glaze. He did state the glaze without the manganese and copper won't work as those two oxides are necessary to flux it. It looks like he's taken a typical Metallic Glaze with high manganese and swapped the redart for custer, kaolin and a bit of talc.

I don't know what Glazy's policy is on posting recipes that aren't suitable for functional ware surfaces with or without a caveat stating so, perhaps that is something to bring up with Derek Au. We do make a point of stating if a glaze isn't suitable for pots coming in contact with food surfaces on this forum and to fire glazes or claybodies, slips and engobes containing manganese in a very well ventilated area.  No, I don't think you are an "old codger" telling people you shouldn't use such glazes inappropriately. 

Edited November 23, 2022 by Min

[Mark C.]

As a potter one should have an understanding of materials and thier use. In terms of safety and use

Not everything in life comes with a warning label.

This is spoken from an old codger

 

[Min]

15 minutes ago, Mark C. said:

As a potter one should have an understanding of materials and thier use. In terms of safety and use

In an ideal world then yes for sure. But, seems there are always going to be people who for one reason or another don't take the time to learn this stuff before diving in. Just take a quick look at social media sites, full of people with no glaze chem knowledge making pots.

[Kelly in AK]

Thera are many variants of this glaze on glazy that have no indication of their food safety (they’re not). There are also crawling, peeling, bubbling, and cratering glazes there too that aren’t food safe and have no “warning” text. In fact, it could be fun to have a contest to find the worst glaze recipe on glazy. 

 I don’t see the glazy site as a one stop shop for people to find easy glazes that satisfy all their requirements without having to think. I also don’t see it as a teaching website for beginners. It can do both of those things to a degree, but also much, much more. 

It’s a user driven database that exists because of good work from generous people. Glaze recipes there have comment fields, a good place to voice concerns. 

The ultimate responsibility for the food safety of my glazes lies with me, and for yours, you.

Now, if you’ll excuse me, I have to get down off this soapbox without breaking a hip.  

Edited November 24, 2022 by Kelly in AK

[Callie Beller Diesel]

From that post:

“This hasn't been tested for food safety and has an unusual composition, so assume it's not food safe unless you can prove otherwise.”

 

Joe’s done his due diligence. If people just try it out without reading to the bottom of one paragraph, I don’t think that’s on him. 

[Mark C.]

ya 

I get it I'm learning to fly airplanes from You Tube  vids what could go wrong?

[neilestrick]

Lots of questionably safe pots out there. Lots of unsafe practices out there in ceramics in general. It's frustrating for sure. There was a FB group that I tried out for about a week before I gave up because I was so overwhelmed with horribly unsafe information being accepted by newbies just because the person saying it made pretty pots and had been doing it that way for 20 years. The last straw for me was the discussion about using a 40 foot long 60 amp extension cord across the back yard from the house to the kiln, and more people saying yes than no.

[High Bridge Pottery]

I am not exactly sure this is the recipe they are trying to create but when places like here publish a recipe with 45% Manganese as  "some of our favorite cone 6 glaze recipes in a convenient recipe-card format, perfect for printing and taking to the pottery studio"  you can't really blame them.

https://ceramicartsnetwork.org/freebies/guide/15-tried-and-true-cone-6-glaze-recipes

[Min]

25 minutes ago, High Bridge Pottery said:

you can't really blame them.

Good to see the warning at the bottom of that glaze recipe.

 

[Kelly in AK]

If you can read the ingredients, you can read the note below, plain as day. I can’t remember an instance where Ceramic Arts Network has published potentially toxic glaze recipes without accompanying information and disclaimers.

I would absolutely blame someone who tried to pass a glaze like that off as food safe or otherwise without hazard. I’ve had probably three “Come to Jesus” pottery moments over the decades, people who knew what they were talking about getting in my face over things I needed to understand better. It’s not comfortable (particularly if you think their work is no good), but I’m deeply appreciative and grateful for those moments. I’ve stood corrected, the only thing it hurt was my pride. I wouldn’t mind helping anyone that way. 

This is, of course, separate and distinct from when people who don’t know what they’re talking about start giving a lot of opinions. In that case, “When someone is making a fool of themselves give them plenty of room.” comes to mind. 

[High Bridge Pottery]

I felt like the OP was more of the opinion that even if you provide a warning is there really any need to share them so I felt it was a bit mean to blame the glazy user when everybody does it.

 

It's good to provide the warning but that doesn't always transfer with the recipe. I think it should be down to the end user to understand what they are dealing with but a lot of people may see a glaze they like and breath through their nose as an extra precaution.

[Bill Kielb]

On 11/23/2022 at 10:27 AM, suetectic said:

I'm wondering what more people feel about these toxic oxides getting used in high amounts to satisfy extended UMF glaze requirements?

Am I just a bit of a codger when I want to tell people just because you can doesn't mean you should?

I think they posted the glaze for its visual result and not necessarily for extended UMF requirements. The flux ratio is in a likely non durable place for many. Part of the problem may be (in the US) to be technically food safe there simply needs to be no cadmium or lead. It also could be just fine as a glaze for sculpture or non food use ceramic products as well.

As others have pointed out there is a warning at the bottom for food safety, definitely always good to add a comment of  additional warnings you may be aware of though IMO.

Edited November 25, 2022 by Bill Kielb

[suetectic]

Thanks for the responses. I'm glad it got people talking.

I wanted to get a sense of how people felt about these metallic surfaces. I know the disclaimer was added but it seemed ot me more of a cya than psa.

this:

13 hours ago, High Bridge Pottery said:

is absolutely how these glazes should be published imo. There's no reason for a glaze like this to be used for functional surfaces imo. trying to make it food safe is only asking for trouble. the use of other metal oxides in this fashion deserves the same very explicit warnings.

I'm biased of course and remember the fallout from the use of lead so I'm sensitive to how ceramics are perceived. We make nice things but waste of bunch of stuff doing it.

lots of us are still just lemmings and goodness knows I've fallen off a few cliffs in my life  and no doubt will again.

hopefully I'll have a bunch of suitable cautions to help avoid any pitfalls. physical or otherwise

[Callie Beller Diesel]

I think when it comes to these really unbalanced glazes, it’s important to remember that not everyone working in clay is a functional potter. The balance of the community that chimes in here (including all the mods!) do tend to be making pots, so we tend to assume that as a default. But if you’re a sculptor, the flux balance is largely irrelevant, as long as you’re getting the surface you want. No one’s checking large scale sculptures for dishwasher safety or cutlery marking. (I mean, they could be. But that’d be weird.)

Do I hope that folks work risk-aware and do things like wear PPE/be aware of ventilation requirements/all the things that will preserve life and limb? Absolutely. Do folks not do that sometimes? Also yes. Should we do our best to educate? Yup. We gonna get ignored sometimes? Yeah. 

[Babs]

You can make the playgrounds so safe kids wont play in them

[suetectic]

20 hours ago, Callie Beller Diesel said:

I think when it comes to these really unbalanced glazes, it’s important to remember that not everyone working in clay is a functional potter.

this is important

some glazes are definitely for non-functional or sculptural work only. the ones I'm most familiar with are clearly labeled first and foremost.

I'm hoping people starting out will recogonise the importance of durable, well-fitted surfaces in contact with food. Call me  Nancy or Karen but I try understand and respect the material I work with. not trying to suggest other pepole don't just putting my cards ont the table as they say. I'm certainly not here looking to win the upvote popularity contest.

I also understand in some regards I'm a bit of a hypocrite.

I'm unsure why atm the playground analogy sits poorly with me. Maybe sculptural work is more playful or maybe fucntional work needs more play. maybe something about kids with matches

regards

[Min]

This has been an interesting thread but I too feel like some comments can get ones back up a bit and I'm not too sure why.

Perhaps it's because many on this forum have been working in ceramics for decades and have put the time and energy into learning how to work with kilns and materials with the respect and knowledge they warrant. It becomes second nature, but it has taken years to acquire this knowlege / experience.

Perhaps there is a bit of unspoken animosity towards some social media type posts, on whichever platform that might be, that blow off this type of learning, usually by a blatant omission of info.

Perhaps there is also the opposite issue of fear mongering in regards to glaze chemistry folklore that is also seen / heard without substantiation. Fear of litigation has shut down more than one ceramics arts dept in schools.

I find that clearly defining what a question is within a post in conjunction with ascertaining a persons knowledge level / experience (hopefully) helps tailor suitable replies.