Colorado’s Ceramics

[NaoTK]

This red glaze is already published in many places, but just for funsies...If we combine the Australia and US SDS we get

Silica <15%
Frit 5-20% (probably 3110 3124 or 3134)
Calcium carbonate+Dolomite <15%
Kaolin <15%
Zinc Oxide 1-3%
Tin oxide <1%
Lithium carbonate <1%
Iron oxide <1%
Copper carbonate <1%
The weird chemicals are flocculants and gums to make it brushable
+ Silicon carbide 1% - magic ingredient not listed but obvious
+ Balance is some feldspar not listed 30-40%

Then you get to work tuning the frit + kaolin + feldspar + zinc to get the cone and look you want. You can save money and create a unique glaze if you make it yourself- and learn a lot!

 

[Colorado]

This red glaze is already published in many places, but just for funsies...If we combine the Australia and US SDS we get

Silica <15%
Frit 5-20% (probably 3110 3124 or 3134)
Calcium carbonate+Dolomite <15%
Kaolin <15%
Zinc Oxide 1-3%
Tin oxide <1%
Lithium carbonate <1%
Iron oxide <1%
Copper carbonate <1%
The weird chemicals are flocculants and gums to make it brushable
+ Silicon carbide 1% - magic ingredient not listed but obvious
+ Balance is some feldspar not listed 30-40%

Then you get to work tuning the frit + kaolin + feldspar + zinc to get the cone and look you want. You can save money and create a unique glaze if you make it yourself- and learn a lot!

View attachment 478912
View attachment 478913
View attachment 478914

Wonderful information, thanks so much!

Now I am starting to feel an itch to start making my own glazes

 

[penumbra]

*Jaw Drop*

This is great information. I was just thinking earlier today that it would be nice to know the ingredients of a glaze, so that a commercial glaze could be reproduced but “tweaked” to be even better for our purposes.

This purple glaze is Amaco ‘Copper Red’

View attachment 478808

Very good of you to share this. I have known a lot of potters and it seems bonsai potters are the most likely to share their "Secrets".

 

[JeffS73]

I'm quite surprised there's a commercial glaze using silicon carbide for local reduction, the tin will help with carbon trapping but I'm still surprised!

 

[Colorado]

I'm quite surprised there's a commercial glaze using silicon carbide for local reduction, the tin will help with carbon trapping but I'm still surprised!

Why the surprise, Jeff? (Excuse my ignorance, I just don’t really know much of anything about the technicalities of glazes so I am eager to learn!)

 

[JeffS73]

Well, copper is green in an oxidation firing but goes red in a reduction firing, which you can't do in an electric kiln (there are ways but they're mostly bad for your kiln).

But electric are the most common kilns.

So some clever people worked out that silicon carbide burns out at a high temperature, which creates carbon monoxide, so if you put a very fine powder in a glaze, the CO from burnout has the same effect as a normal reduction firing, which can turn copper red.

My surprise comes from the fact that silicon carbide is not as reliable as a proper reduction atmosphere, and can cause 'cratering', it is more commonly used for crater glazes. Amaco know their stuff though, the chemistry must be really good to be that reliable. So bravo Amaco!

Here's a pot with a celadon glaze I made using silicon carbide:

It worked quite well, i was cautious about glazing thicker because it risks carbon trapping, which can be cool but i wanted a true celadon.
I've decided some glazes just need to be fired in reduction properly!

 

[Colorado]

Well, copper is green in an oxidation firing but goes red in a reduction firing, which you can't do in an electric kiln (there are ways but they're mostly bad for your kiln).

But electric are the most common kilns.

So some clever people worked out that silicon carbide burns out at a high temperature, which creates carbon monoxide, so if you put a very fine powder in a glaze, the CO from burnout has the same effect as a normal reduction firing, which can turn copper red.

My surprise comes from the fact that silicon carbide is not as reliable as a proper reduction atmosphere, and can cause 'cratering', it is more commonly used for crater glazes. Amaco know their stuff though, the chemistry must be really good to be that reliable. So bravo Amaco!

Here's a pot with a celadon glaze I made using silicon carbide:
View attachment 478957
It worked quite well, i was cautious about glazing thicker because it risks carbon trapping, which can be cool but i wanted a true celadon.
I've decided some glazes just need to be fired in reduction properly!

Very interesting, thanks Jeff! I have a lot to learn

 

[Carol 83]

Now I am starting to feel an itch to start making my own glazes

But the purple one you have been using is awfully pretty...

 

[Colorado]

Here is a fun one that I am looking forward to using this season! It is a mame tray. I watched this video on YouTube posted by @Eric Schrader on Bonsaify:

Bonsaify on Instagram: "New video! In "Mame Tricks: Repotting and Rebuilding a Mame Tray", Eric shares growing and maintenance tricks for mame bonsai. https://youtu.be/bWT-dXe7OeY #mame #mamebonsai #mametray #bonsaify #bonsaiforyou #bonsaivideo #er

164 likes, 5 comments - bonsaifyonline on January 16, 2023: "New video! In "Mame Tricks: Repotting and Rebuilding a Mame Tray", Eric shares growing and maintenance tricks for mame bonsai. https://y...".

www.instagram.com

So I made this:



It is about 15” x 7”. It will only fit 3 or 4 mame trees probably, but that’s all I’ve got anyway.

 

[Colorado]

I reglazed and refired that f-ed white oval from earlier in the thread @sorce

 

[Colorado]

Here’s a wonky one. I don’t even know what I did to make the rim do the wave but here we are

 

[Colorado]

Small round, light purple glaze

 

[August]

So I see you've made leaps and bounds in firing; where are you at with appraising?

I gotta come over and buy one of these from you soon!

 

[Colorado]

So I see you've made leaps and bounds in firing; where are you at with appraising?

I gotta come over and buy one of these from you soon!

Thanks for the kind words! Just let me know when you want to come by

 

[Kanorin]

Here is a fun one that I am looking forward to using this season! It is a mame tray. I watched this video on YouTube posted by @Eric Schrader on Bonsaify:

Bonsaify on Instagram: "New video! In "Mame Tricks: Repotting and Rebuilding a Mame Tray", Eric shares growing and maintenance tricks for mame bonsai. https://youtu.be/bWT-dXe7OeY #mame #mamebonsai #mametray #bonsaify #bonsaiforyou #bonsaivideo #er

164 likes, 5 comments - bonsaifyonline on January 16, 2023: "New video! In "Mame Tricks: Repotting and Rebuilding a Mame Tray", Eric shares growing and maintenance tricks for mame bonsai. https://y...".

www.instagram.com

So I made this:

View attachment 479068View attachment 479069View attachment 479070

It is about 15” x 7”. It will only fit 3 or 4 mame trees probably, but that’s all I’ve got anyway.

Very nice! Something like a juniper raft would look great in this kind of pot as well if you ever want to do something else with it.
Enjoying the thread, keep it up!

 

[Colorado]

Well I haven’t made any pots in months because this summer we moved to a new house. Last few months have been so busy with moving, work, unpacking, etc.

I’ve been working for the past few days to get all my pottery gear organized and set up in the new place! Last night I got home from work after a long week and fired up the wheel….just like riding a bike, I’m back in the game!

 

[Apex37]

Still would love to get a pot from ya TJ! Just let me know once you open back up to commissions.

 

[Colorado]

Still would love to get a pot from ya TJ! Just let me know once you open back up to commissions.

Awesome! Would love to make a pot for you. I’ll send you a PM.

 

[Carol 83]

Still would love to get a pot from ya TJ! Just let me know once you open back up to commissions.

You'll be very pleased!

 

[Hartinez]

Still would love to get a pot from ya TJ! Just let me know once you open back up to commissions.

You'll be very pleased!

Yes. TJs pots are legit. Just getting better each new piece.