We’re Home!


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Thanks everyone for coming out to the Melbourne Art Festival this weekend.  We had a great time and enjoyed meeting so many awesome patrons and fellow artists.  One of the highlights for us was our next-door tent neighbor, Bonnie Carter, who is a fabulous watercolor artist.  Bonnie doesn’t do your typical “watery” watercolors.  She’s not afraid of color and vibrant subject matter.  Please check out her paintings at http://bonniejcarter.com/.


The Melbourne Art Festival 2010


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Come see us this weekend in Melbourne, Florida!!!

The Melbourne Art Festival 2010

April 24 and 25, 2010




Festival Map


I’m so behind! So, here’s another random pottery picture.


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I was just looking back through my Glossary of Glaze Colorants and realized that I still have a lot of work to do on it.  A picture is supposed to go everywhere you see a little bracketed piece of blue text.  I have these test-pots ready to be photographed, but just haven’t had the time to set them all up and shoot them yet.  After the spring shows are over, I promise, I’ll fill in these gaps.

In the meantime, please enjoy random pottery picture number 4.  Maybe it’s 4?  I lost count.  We really enjoy making canisters and here’s a trio of them.  Robert, of course, threw them and turned them.  If you’d like to know more about throwing and turning, ask Robert.  I keep trying to get him to write an article and he keeps forgetting!  So, here I go chattering about the glaze…

After bisque firing, I glazed the group in my Mossy Mahogany Glaze (you know I like my glitzy names).  Many of you may have seen the first version of my Mossy Mahogany last year.  It was nice but not spectacular.  I spent a lot of time revamping it so it would shine even more.  What this picture does not show are the little gold crystals that dance around in the upper amber portions of the glaze.  It’s a real pain to apply – too thin and it’s just brown, too thick and it runs all the way down the pot during firing in olive drab puddles.  Sometimes, it runs onto the shelf (hence the angle grinder – which was surprisingly anticlimactic in actual use yesterday, phooey).  I am sure with time I’ll get more used to it, at which point, I will be bored with it and change it again or come up with another glaze and discontinue this one.  Enough talk.  Here it is:

Promethean Pottery - Mossy Mahogany Canisters

Promethean Pottery - Mossy Mahogany Canisters

How We Make Pottery – in Pictures


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For our booth display, I decided we needed some pictures showing how we make pottery.  Having been brought up as a good little scientist, I decided a PowerPoint presentation was the best answer.  So, over the course of a few weeks, I took pictures of Rob and he took pictures of me doing our respective things.  They all got narrated in presentation format, printed, laminated, and hung up in the tent at our last show.  I think the amount of information might have overwhelmed people.  Hmmm…  What do you think?

Robert throwing a canister. Promethean Pottery

Robert throwing a canister.

Robert throwing a lid. Promethean Pottery

Robert throwing a lid.

Robert trimming a bowl. Promethean Pottery

Robert trimming a bowl.

Emily putting handles on mugs. Promethean Pottery

Emily putting handles on mugs.

I’m always struck by how awkward mugs, pitchers, creamers (anything with a handle) look before they are bisque fired and glaze fired.

Emily signing and waxing bowl feet. Promethean Pottery

Emily signing and waxing bowl feet.

I didn’t take any pictures of us sanding pottery.  I just didn’t think that was very interesting.  After I wax over the signature, each pot gets a bath with the hose.

Emily glazing canisters. Promethean Pottery

Emily glazing canisters.

What these glazing pictures don’t show is all the time and energy I put into formulating new glazes.  All of the glazes we use are formulated by me and I’ve done over 2500 individual tests (at last count, meaning I’ve lost count and it’s probably a lot more than that by the time you’re reading this).  Our house is cluttered by boxes and boxes of little tiles and testpots with hideous glazes on them!

Emily glazing lids. Promethean Pottery

Emily glazing lids.

Morning Routine – Kittehs, Koffee, and Kafka


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I’m usually up first in the morning – like now.  I like to spend quality time with the kitties (they’re actually already outside except for MooMoo, who’s at my feet) and some coffee before I get started on whatever random project is looming from the day before.  Today, sanding, signing waxing and washing several large canisters is looming as is figuring out how to grind melted glaze off of kiln shelves.  The up side is I get to play with my new angle grinder.  The down side is that I have no idea what I’m doing!  Thankfully, all the different forms of taxes are finally done – thanks in large part to my brilliant mother.  So, I can – and should – focus on pottery again.

Emily signing pots

Emily signing pots

But in the morning, with my coffee and my kitties, I like to read through some of my favorite blogs.  It’s really the only kind of news I care about.  You’ll never find me cuddling up to a newspaper.  Call me oblivious.  This morning, I’m reading Jim’s latest posts on his blog: Sofia’s Dad’s Pots.  He has a very readable style of writing (that my early morning brain can follow, better than Kafka) and his pots are stunning.

OK, I’ve justified my laziness by means of this piddly post.  So, now I’m off to work.

Great Weekend, Thank You All!


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I just wanted to say thanks to everyone who came out to see us this weekend at the SFCC Spring Arts Festival.  We had a great time and really enjoyed meeting all the new folks as well as seeing some old friends.

The next two weeks will be spent restocking for our next show:

The Melbourne Art Festival 2010

April 24 and 25, 2010


This will be our last show during Spring 2010.  So, please come out to see us if you can.  As always, you can find out which shows we will be participating in here.

Late Night Kiln Opening and Glaze Testing Again


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The day before yesterday, I finished glazing enough (real pieces and tests) for a full kiln and got the thing on pretty late.  If you’ve read our “About Us“, you know we fire up to cone 10 and it takes around 24 hours.  The kiln went on around 8pm, and we could finally crack it about 11pm last night.  I had about 60 test tiles in this load and couldn’t bear to wait.  I had really high hopes.

As I was pulling stuff out of the kiln, I got more and more depressed because the actual glazes did not meet my expectations – as they never do.  For some reason, I always start imagining the greatest chemistries are taking place in my little personal volcano, but the reality is typically less impressive.  So, I pulled them all out, left them sitting in the studio and went to bed.

This morning, we brought the tiles in, and Rob said that he didn’t think they were as bad as I might have presumed.  So, we went through them and there are some (I think) pretty fantastic new glazes in there after all.  I didn’t get the blue I wanted, but there’s a nice blue-green in there, a better version of our old Mossy Mahogany (richer, darker, with gold crystals on top), a waterfall green (same as last kiln, just re-tested), a silica white (again, same as last kiln, just second testing), a pale variegated cream that I didn’t expect, and yet another saturated iron glaze which I can only describe as a cross between hare’s fur tenmoku and tea dust but with gold crystals scattered over the surface.  I love iron.  It never lets me down.

So, the moral of the story is to not open the kiln late at night when you’ve had to force yourself to stay awake.  You won’t like anything that comes out of it and you’ll just be more exhausted the next day.  Also, I reiterate, taking pictures of shiny glazes is really really hard!  You HAVE to click on / zoom into these pictures.  The thumbnails do not do them justice.

I’d love to hear suggestions for names on the blue-green and waterfall green.

For more information about glaze colorants, see the glossary I wrote here as well as my article about saturated iron glazes.

For those of you who are interested, there’s also a picture of Isosceles sleeping in my butt.  Lovely. 😛

Test Tiles Work Like a Charm


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Last week, I unloaded a kiln full of only glaze tests which I did on the new test tiles we made with the extruder.  I have to say that I am very pleased with the performance of the tiles themselves.  The glaze tests are another matter.  Let’s just say that out of a few hundred combinations and recipes, I think I’ll keep or expand on maybe five.  I keep telling myself that you never know what a recipe is going to look like until you fire it in your kiln under your conditions.  That’s my justification for appearing to waste so much time and energy.

In addition to 12 line blends, I also took all of my existing glazes and tested them over and under each other.  That’s 8 x 8 = 64 tiles right there.  In general, my glazes do not play well together in terms of appearance.  However, this was very educational, and now I know which ones combine to do something interesting, if not attractive.  I can also safely say that none of the combinations seem to crawl off one another or anything else catastrophic.

I did manage to generate some interesting purples, a new silica white, a medium waterfall green, a floating green-on-brown, and a floating blue-on-black (à la Midnight Peacock, but simpler because it’s one glaze not two, woo hoo!!!).

I also learned the following tidbits which might help you in some of your testing.  Remember, everything is dependent on the chemistry of the base glaze and your firing schedule.

(If you’re reading this article, you’ll probably be interested in my Glossary of Glaze Colorants as well.)

1.  Although lithium (from lithium carbonate, spodumene, or petalite for example) contributes to a lovely glaze finish in some base glazes, it can also kill certain color responses.  For example, at our temperature, I can get some great iron greens in certain feldspathic base glazes.  However, adding an appreciable amount of lithia-containing mineral to these base glazes make them turn an unimpressive brown.

2. Maybe this is obvious:  Two base glazes which have the same oxide analysis but use different minerals to get there do not necessarily look the same when fired.  For example, you can get calcia from whiting or from wollastonite (and others).  If you substitute wollastonite, you obviously have to decrease your flint content, to keep the silica the same, but once everything is adjusted and the molar amounts of all the different oxides are similar (within 0.1) you aren’t guaranteed that one base glaze will fire like another.  Fascinating, isn’t it?  From a purely chemical standpoint, one might assume that oxide source wasn’t nearly as important as final oxide content.  However, it seems that source does matter.  So, choose wisely.

3. Calcium does indeed have a bleaching effect on iron.  I don’t know if you would see this in a (high) iron-containing glaze, but in a clear glaze, increasing the calcium content will bleach the tan appearance coming from the iron in the clay body.  This is particularly noticeable on our white stoneware.  We use Phoenix from Highwater Clay which is pretty darn white in oxidation at cone 10.  However, there is a noticeable difference when clear glazes that differ only in calcium content are used on this body.

4. Black iron oxide (FeO) and red iron oxide (Fe2O3) perform differently in the same base glaze.  Now, I’m not talking about intensity of color, since by weight, red iron oxide is not as “strong” as black as there are more iron atoms in a given weight of FeO than Fe2O3.  At cone 10, Fe2O3 breaks down to FeO and thus, if correcting for molecular weights, one should be able to obtain the same color from FeO as Fe2O3 if you adjust the percentage correctly.  However, red iron oxide, in my experience, consistently generates a warmer brown than does black.  Browns made from black iron oxide tend toward a grey-green cooler hue versus those made with red which are warmer, more like burnt sienna.

5. Very small amounts of chrome in the appropriate base glaze are awesome and can do some miraculous things.  In the wrong base glaze it turns out cat-sick green.

6. Magnesium causes copper to tend toward a warmer and softer green whereas lithium generates yellower greens.

7. The titanium dioxide in rutile can have a lovely effect on basic cobalt blue, however, you have to be careful of the pinholing that is associated with adding TiO2 to a glaze.  I have worked on ameliorating this phenomenon by extending what I refer to as the “open” time of a glaze.  By that I mean, the amount of time a glaze is molten in your kiln, before a skin has formed on the glaze surface through which bubbles have to pass contributing to pinholing.  Logically, you can extend the open time of the glaze by maintaining its maturing temperature for longer either through heat or chemistry.  If you’re trying to extend the open time via different fluxes, you may need to take into account the temperature at which compounds such as oxygen or carbon dioxide are evolved from the molten glass.  Please note that “open time” is my own special word, meaning if you use it in front of someone other than me, they probably won’t know what you’re talking about!