Pottery beginnings

[CodeMonkey]

Very nicely done.

Thanks Penumbra, I was hoping for a little more depth and variation in colour but I'm happy with how they turned out.

I have also discovered over the last few weeks that my current favourite clay (to build with) doesn't take oxides well. It doesn't really take glaze well either! And I don't like it unglazed.
I've done around 300 glaze tests this month. Made a little progress but there is definitely something I'm missing. Be it the clay, or my firing technique. I've had some results that don't just don't make sense to me yet.

Any one here clued up on making their own glazes? I could really do with some insight. I'll be reaching out elsewhere too. Hoping I can find someone nearby.

 

[penumbra]

I seldom make glazes anymore. It is a bit of work that requires extreme caution and is not always consistent and materials vary from batch to batch.
I am a bit stymied by statement that you current favorite clay doesn't take oxides well. Share with me your procedure and results.

 

[CodeMonkey]

I seldom make glazes anymore. It is a bit of work that requires extreme caution and is not always consistent and materials vary from batch to batch.
I am a bit stymied by statement that you current favorite clay doesn't take oxides well. Share with me your procedure and results.

Maybe the word "take" here was incorrect. It is more the visual results that I dislike.
I have tested the following oxides: Red/Black iron, rutile, copper, chrome, ilmenite, cobalt. Out of all of them, only the BIO results in something visually appealing (at least to me). I think it's because of the yellow/buff colour the clay matures too.
I mix the oxides with Gertsley Borate for a bit of adhesion and apply to Bisque ware, this seems to work ok.

This also means not many translucent glazes look good either. Which I was banking on for some of my textured pieces. It's all good though, I've learnt from it and will reserve this clay for items that will have opaque glazes.

 

[CodeMonkey]

Here's an example of some of the glaze issues I need to work out.



There were 2 things different between these tiles. One is the clay body (buff vs white) the other is that the buff was fired upright where as the white was flat.

I wish I had fired the white standing up but I ran out of room. A few of my tests look like the tile on the left. Completely washed out. All if these recipes contained copper so my theory is this acted like a flux in the melt and was driven off. Except the glaze pooled on the flat tile.

I'll be doing a run of tests with different amounts of flux in my future firings.

 

[penumbra]

Well it sounds like you are figuring it out but have a way to go. I guess we all do. Let me ponder this.

 

[sorce]

I'll be doing a run of tests with different amounts of flux in my future firings

Melted is melted so I wouldn't vary the flux by too much, if at all, at least not first.

Were they both dipped upsidedown?

Seems the problem is more of thickness, amount.

Are you measuring specific gravity?

Sorce

 

[CodeMonkey]

Were they both dipped upsidedown?

Seems the problem is more of thickness, amount.

Are you measuring specific gravity?

They were both dipped at an angle to try and keep the back clean. 1 dip for 3 seconds fully, then another 3 sec dip on the top half. It does look like the larger tile may be slightly thicker.

I have been measuring sg but I don't find it much use for test tiles (as I don't know what I'm aiming for). I do use it to repeat a glaze that I like of course.

My vertical test tiles were pretty tightly packed. That could have had an impact.

I've got a lot of distinct issues to figure out so i guess it's focus on one at a time.

 

[sorce]

They were both dipped at an angle to try and keep the back clean. 1 dip for 3 seconds fully, then another 3 sec dip on the top half. It does look like the larger tile may be slightly thicker.

I was thinking, because it looks as such, that the allowing it to drip back down upside-down would have caused the top half to be thicker.

I believe that "thin" angle of dip, may be more the culprit, as you are dipping into that highest realm of what would be mostly water. I would consider the first 2-3mm of any glaze useless as a rule, even if vigorously stirred directly before dipping.

My vertical test tiles were pretty tightly packed. That could have had an impact.

Tightly Packed...as in pores of the bisque? That will have more of an impact on outcome than position in the kiln, though, I don't necessarily believe different bisque temps matter as great as some.

I'm not exactly an advocate for measuring SG, but I would consider it important in trial phases, at least until you become comfortable knowing you are "close enough" by look and feel. Knowing it now is going to give you the target to aim at, I would consider this More important for test tiles.

There is something to be said about "commercial" information and how it...it is kinda like that watery part of the glaze....shallow! Especially when it comes to things like "flux". There is a crazy deeper understanding of it, and the actual characteristics of glazes that I didn't find until researching ash glazes. Even if you don't intend to use them, having this information will help you keep tests to a minimum, and more quickly understand what may be going on.

My Ash Glaze Rabbit hole started here.

Ash Glazes — Derek Philip Au

All of the following ash glaze recipes and more can now be found on my new open-source ceramics recipes website, Glazy: https://glazy.org/search?base_type=460&type=1060 I’m not particularly an ash glaze aficionado, and I’m far from an expert. But it’s

derekau.net

Lotta resources on that link.

Cheers!

Sorce

 

[CodeMonkey]

Any of you wonderful potters out there got any tips for storing/sorting test tiles?

I feel I need a system to be able to refer back when needed. Currently using notes and photos for quick reference.

 

[sorce]

Any of you wonderful potters out there got any tips for storing/sorting test tiles?

I feel I need a system to be able to refer back when needed. Currently using notes and photos for quick reference.

View attachment 412337

I'd Velcro those onto a board so you can remove them for viewing in different lights.

Seems you're not getting much running, but I would consider a based tile to stay safe 100%. It also allows for a vertical and horizontal read on one tile.

I'm not big on organizing tests myself, but nicely organized boards are quite impressive, though I feel the mass of options can be overwhelming.

Depending on how you work, I think you can dial in a more useful system.
Because I brush I been thinking about making cups glazed with each glaze to use for each glaze, but only when I'm sure they are "keepers".

Don't be afraid to throw stuff out! I have come to love the sound of an old test tossed in the bin.

Perhaps a code(monkey) of like....a Roman Numeral for a specific base, then a letter for the colorant, R rutile, C cobalt, and a third number for the amount of colorant can be useful.
V R 3, IV C 2, etc.
That way the only thing you have to look up is the base.

Something to be said as well, about foot long tiles, where you can overlap glazes and get that information too.

Sorce

 

[penumbra]

At the local college they are hung on the wall.

 

[CodeMonkey]

Thanks both,

Some good ideas.
I can already see the need for larger test tiles. I should probably put a hole in them more consistently too and hang the keepers on a peg board near my glazes.

I like the idea of based tiles. I currently fire my vertical tiles stood up in a kiln brick that I've cut groves into. Works well as if it runs, the kiln brick is so sift you just break a bit off.
Time to purge some of the failed tests!

 

[penumbra]

Time to purge some of the failed tests!

Its always time to purge.
I have never been one to keep things to remind me of my past mistakes. I can remember them all to well.

 

[HorseloverFat]

Whoah! I’m behind here!! i make Almost ALL my own glazes..

What cone range are we looking at for melting..

Let’s talk fluxes.. there are many...

Let’s talk flux BLENDS... because any ONE has issues that you have to pre-empt for certain finishes (matte/clear/“controlled craze/ Ash/ chem) and certain temp
Ranges..

except boron... super stable borate is one that can stand alone.. but still melts early (if your firing to cone 6) so colors will be darker and glaze will need more alumina to control.



(My most common flux blend is Na, Mg, and trace amounts of Potassium.... but i have begun zinc-speriments! And an QUITE familiar with Boron from my time spent in low-fire earthenware processing.

 

[HorseloverFat]

I’m starting Cr02 experiment MOSTLY for color.. but testing flux capacity as well.

 

[CodeMonkey]

Whoah! I’m behind here!! i make Almost ALL my own glazes..

What cone range are we looking at for melting..

Let’s talk fluxes.. there are many...

Let’s talk flux BLENDS... because any ONE has issues that you have to pre-empt for certain finishes (matte/clear/“controlled craze/ Ash/ chem) and certain temp
Ranges..

except boron... super stable borate is one that can stand alone.. but still melts early (if your firing to cone 6) so colors will be darker and glaze will need more alumina to control.



(My most common flux blend is Na, Mg, and trace amounts of Potassium.... but i have begun zinc-speriments! And an QUITE familiar with Boron from my time spent in low-fire earthenware processing.

Finally got round to actually catching up on posts. It's been a busy few weeks.

I've been firing to cone 8, Although tried to hit 9 last time and massively over shot
As you can probably tell I've done a lot of glaze research and testing recently. I think I'm starting to get a grasp on it, but have a long way to go yet.

I don't tend to use boron (if I do it's a small percentage. Maybe I should be more open to it?). I've been trying to dial in some base glazes (among other things!) where the main fluxes are usually Potash Feldspar and calcium carbonate.
Although, I really love strontium. Strontium and Soda Feldspar or Neph Syenite with lower amounts of silica/alumina seems to be my go to at the minute for a matt/satin glaze.

Also had some good success with a Neph Syenite and dolomite (for the mg) satin base. Takes colours really well. Only downside I need to work out is it's got a slightly too high sheen. Looks like crystallisation to me so likely a result of me messing with slow cools.

I've had some some great results, but way way more rubbish ones! I'd love any input/info you can give.

 

[CodeMonkey]

A few pots ready for bisque firing in the next week or so.
Been on a bit of an oval exploration and trying out some new clays! One of them (oxidising ST Thomas) is soooo smooth, it's quickly becoming a favourite. yet to fire it though...

Still working on getting the oval walls to be at a consistent angle all round. creating my own wooden ribs/guides is proving very useful.

 

[CodeMonkey]

Also trying out a high iron red/brown firing stoneware clay too. I managed to order the high grog version by mistake at first so there will be plenty of chunky textured pots to use it up.
Planning for these to be unglazed. Potentially with some oxide highlighting.

I've got to see if the texture survives the firing first! Testing a new technique.

 

[CodeMonkey]

Got myself some of the finer grogged red clay.

Knocked up a couple of pots to test. I still need some more practise with smoothing grogged clay...

 

[penumbra]

Really nice work. I am glad you are in the UK else I would be concerned.
You just need to burnish your pots to push the grog into the surface. Even a very coarse and heavily grogged clay body can have a very smooth surface.