Back on the wheel and colorful clips

Nicely focused from my recent glaze firing, I got back on the wheel yesterday  for a lovely couple of hours of throwing and made some more flat bowls/plates.  ”But what are they FOR?” asked Nick, ever the pragmatist (well, one of us has to be).  Well, I could go on and on about what you could use these for.  But most importantly, at this point in the venture, the bowls will be stars in my next stage of glaze testing.

This low bowl shape is fairly new in my repetoir:  I started making it at the end of my tenure in the UK.  I really like glazing this  simple shape, as it serves as a great canvas for highlighting glaze interaction.  My first glaze testing showed the potential for some very cool glaze interactions, and some more cool bowls to come!  Oh my fingers are itching in anticipation!

And thinking towards that not so distant future, these little bowls are prototypes of larger low bowls that I’ll make once I have a bit more glaze testing done.   Sacrificing a 12oz bowl is one thing, 3-4 pounds of clay a pop is another…).

On another note, did you notice that cute green clip in the photo?  The the other day, I picked up a pack of colorful clips (at a $1 for 6, how could I resist?).  I thought they’d be perfect in the studio.  Yesterday, I finally put them to good use to keep my plastic sheeting in place over my newly thrown bowls (wicked wind in the studio today!) and, to clamp a sponge to the inside of my water bucket (for wiping off wet/dirty ribs while throwing).  I think I’ll pick up another pack of these today.  Mighty useful little things!

 

Glaze testing 1.0

Let’s get back to the pottery now, shall we????  :-)

Ok folks, this is quite long so get your cuppa coffee or bevarage of choice.  I was going to try to keep this brief, but found that writing was helping focus my thinking about the results and where I want to take them.   If you’re not interested in the technical aspects of glaze testing, feel free to skip to the end, where photos await!  :-)  However, as I myself read the ins and outs of every glaze testing report I could find before I fired my first kiln, I kept this as detailed as possible.  Hopefully this information will indeed be interesting and helpful to someone out there! As folks will tell you, there is no replacement for running your own tests. I found this to be indeed true and happily, next round of glazing will be much more focused.

But I digress!   As many of you know, this was my very first glaze firing in my new L&L e-28s and the first time that I’ve mixed up glazes in Puerto Rico.  In the UK, I fired to cone 8-9, but I’ve decided to go down to cone 6 for economic reasons.  However, as I was very impressed with the lovely range of Cone 6 glazes out there,  it really was not a big sacrifice.  It did mean I was starting from scratch as far as glazing was concerned!  This was my first round of glaze testing.

My goals in testing were to:

1. assess glaze fit and appearance on the two clay bodies I’ve been testing: Standard 240 and Axner’s version of B-Mix, Maccabbee (Mix 5).  From my throwing experiences, the Standard 240 is so far winning the race.
2. narrow down the list of glazes I want to mix up in large quantities
3. identify interesting glaze  interactions/overlaps for future work
4. develop a nice celadon-like  green glaze for my Sea-Grape plates
5. develop another brown glaze
6. successfully fire a cone 6 glaze kiln (following MC6G guidelines and firing schedule) for the very first time!!!!

I mixed up batches of the following glazes from “Mastering Cone 6 Glazes” by John Hesselberth and Ron Roy (see book for recipes):

• Raw Sienna (1000 grams)
• Waterfall brown (200 grams)
• Bright Sky Blue (500 grams)
• Variegated Blue (500 grams)
• Licorice Black (500 grams)
• Glossy Base Glaze 2 (100 grams)
• Glossy Base Glaze 2 + 1% copper carbonate (200 grams)
• Glossy Base Glaze 2 + 3% copper carbonate (200 grams)
• Glossy Base Glaze 2 + 6% RIO + 4% Rutile (200 grams)
• High Calcium Semimatte Base 2 + 1% copper carbonate (200 grams)
• High Calcium Semimatte Base 2 + 0.5% copper carbonate, +0.5% cobalt carbonate (200 grams)

I had prepared a good amount of small work (espresso cups, small bowls, handbuilt plates) for glazing.  As I’ve previously mentioned, I could not fathom filling my 28-S (all 6.8 cubic feet of it) solely with test tiles.  I realized going in that this was a bit risky and potentially a lot (even all) of the work would be a wash.  But hey, I got a good amount of throwing practice out of it and the name of the game is testing, right?  All work was bisque fired to cone 04, as per MC6Gs  recommendations.

The recommended minimum amount for a glaze testing by the authors is 200 grams of glaze, which is really not much at all!  It is fine for dipping test tiles (of which I had many) and was also useful for very small test items (shell pendants, magnet disks).  I also was able to use the smaller quantities by pouring into (then out) of my small espresso cups.  On the other end of the scale, 1000 grams is quite a good amount of glaze, and I was able to glaze the way I normally do, by using tongs or holding wares to complete quick “in and out” dips.  The resulting glaze application was even and thinner than any other method I used to compensate for smaller amounts of glaze.  I found that 500 grams was a much better  amount for my purposes than 200 grams.  I was able to dip larger pieces (especially if I was only applying to glaze to part of a pot) but still  didn’t have the “depth” for complete quick dips. This of course resulted in greater glaze thickness (and not the most even glaze application). But glaze application with 500 grams of glaze was indeed closer to how I normally would work with glazes.

Before I share photos of my results, a few findings, observations and reflections:

First, regarding the new recipes I mixed up (variations on MC6Gs):

• Glossy Base Glaze 2:

Nice transparent glaze.  With the Standard clay, this means slightly yellowish (really only noticeable to me when held up against a whiter clay body).  I tested it with some Mayco Stroke and Coat underglazes and the underglazes showed up true to color under this glaze. In other words, it was transparent!

• Glossy Base Glaze 2 + 6% RIO + 4% Rutile (Temporary name, variegated bluish-brown):

Boy we liked this one!  It is brownish/mauvish/creamish/bluish in its variegation.  When very thin (and where it breaks on patterns), it is a lovely brown.  Beautiful.  Definitely mixing up a larger batch to further test this one

• Glossy Base Glaze 2 + 1% copper carbonate and Glossy Base Glaze 2 + 3% copper carbonate:

Both give nice greens.  The smaller percent does look like a very light celadon (on my light clay body).  The higher percent is quite a vivid green and Nick is quite partial to it.  Both would work well for my dishes but I think we’ll also try 2% next time!  :-)

• High Calcium Semimatte Base 2 + 1% copper carbonate:

A nice, even covering semimatte glaze, light green with delicate light crystals.  Created some really glaze effects when poured over Licorice Black and Raw Sienna (kinda like “Hare’s fur”)

• High Calcium Semimatte Base 2 + 0.5% copper carbonate, +0.5% cobalt carbonate

Very nice blue and again, as above, nice glaze effects with Licorice Black and Raw Sienna.  Will continue to explore.

Other notes:

• As far as glaze application goes, the glazes all went on the clay bodies very nicely.  They dried to a hard shell (i.e., not powdery) which made it easy to handle and  multiple dip pieces.

• For a first firing, I was very happy with my results.  No major catastrophes (I was well prepared for glaze runs with 3 layers of kiln wash AND kiln washed biscuits under each piece but suffered none!),  lots of awesome results, lots of learnings and good focus for future experiments AND future glazing.

• My Variegated blue and Bright Sky Blue could have (should have) been a tad thinner.  Due to the application challenges, a few areas were clearly too thick.  Where very thick, the variegated blue pinholed a bit.

• Overall, the glazes (at least to my eye) present as they do in the book on porcelain.  For example, my variegated blue looks a lots like figure 6-12 in the book and not at all like figure 2-5 (which is unfortunate, as the latter is actually the look I prefer).   Perhaps this would be different if the glazes were thinner? Not so much?   As we used to say in academia, “It’s an empirical question!” and more testing will reveal the answer.

• I could see no major differences (to the naked eye) vis-a-vis glaze fit for the Standard and Axner clays.  All glazes stayed put (no running below glazing line) on both clay bodies, expect for the waterfall brown of course.

• My one “complete wash” of the firing was a bowl with waterfall brown poured into a bowl, swished around to cover, then out.  I applied licorice black to the outside.  The resulting glaze application of waterfall brown was clearly far to thick on the inside bottom of the bowl (where the glaze most have also pooled down the side), and actually blistered!  As I kept the glaze inside the bowl, no harm done, major lesson learned!  :-) Test tiles and small flat pieces with waterfall brown show its promise and I’ll keep playing around with it.

• The bright sky blue is VERY bright.  I can see using it in combination with other glazes but probably not on its own.

• I mixed up a nice sized batch of Raw Sienna as I thought it would be a winner and it was!  Very nice brown with slight color variation and subtle changes from matte to glossy where thickness varied and nice crystallization.  Looks really sharp with Licorice Black but also interacts nicely with Variegated blue.

• Licorice Black is lovely.  Smooth black, and interacts well with other glazes (a characteristic that is very important to me).  Where it breaks (on texture and rims) it broke brown.  Favorite combos:  under and over variegated blue and over and under bright sky blue.

• Other combos I really liked:  Variegated blue over Raw Sienna, Variegated bluish-brown over licorice black, raw sienna over black.

• Standard 240 fires to a creamy slightly yellow color (see following pictures) whereas Axner’s Maccabbee fires more white/gray.  This is most evident in the comparison of the two clay bodies with Basic Glaze Base 2.  This is not an issue for me but it might be for others.

So now, without further ado, here are some images (click on any image to enlarge).  First, test tiles with single glazes.  The back row is Standard 240 (top of tile was double dipped), the front row is Axner’s Maccabbee (single dip).

Verigated blue, Licorice black and Raw Sienna

Waterfall brown, Bright sky blue and Glossy base glaze 2 (note visible difference between the two clay bodies for the latter).

GBG2 with 3% copper carb, GBG2 with 1% copper carb & GBG2 with 3% copper carb & GBG2 with 6% RIO + 4% Rutile

HCSB2 with 0.5% copper carb & 0.5% cobalt carb, HCSB2 with 1% copper carb

The following images illustrate my favorite results from the firing:

Wheel thrown cup (2×2.5inch).  Standard 240.  Licorice outside, Bright sky blue inside (overlap on inner rim)

Wheel thrown cup (2×2.5inch).  Standard 240. Verigated blue outside, Licorice black inside (overlap on inner rim)

Wheel thrown cup (2×2.5inch).  Standard 240.  Raw Sienna (glazed in one dip)

Wheel thrown cup (2×2.5inch).  Standard 240.  Black licorice outside,  Variegated bluish-brown inside (overlap on rim)

Wheel thrown bowl (4.5inch diameter).  Standard 240.  Varigated blue over licorice black

Wheel thrown bowl (5inch diameter).  Standard 240.  Bright sky blue over Licorice black

Wheel thrown bowl (5inch diameter).  Standard 240.  Licorice black, Raw Sienna with  HCSB2+.5%copper carb+.5% cobalt carb poured over overlap and negative space

Wheel thrown bowl (5inch diameter).  Standard 240.  Licorice black, Raw Sienna with  HCSB2+1%copper carb poured over overlap and negative space

Hand-built plate (3.5×3.5inches), Standard 240.  Variegated bluish-brown over Licorice black

Hand-built plate (3.5×3.5inches), Standard 240.  Raw sienna over Licorice black.

Handbuilt slab vase (5×3inch) textured Axner Maccabbee.  Variegated blue over Raw Sienna

So what’s next?  I plan to mix up larger batches (1000-2000 grams) of a few of the glazes and mid-sized batches  (500 to 1000) of those I’m not quite ready to commit to yet but want to further explore.  I can forsee having some glazes that never get mixed up in batches larger than 1000 grams, as I only use them as “special effects” glazes (e.g., bright sky blue).  Time will tell!

There are a few more small batch (200 grams) experiements I’d like to try out, based on the results of this firing (e.g., playing around a bit more with levels of copper carbonate in GBG2).  And, I  want to play around with the colorants in Licorice a bit to get a deep brown (of course, Licorice Black is definitely staying on the menu!).

I’m also planning to mix up some Raspberry (from MC6Gs) and Jeannie’s Purple, which is based on Raspberry.  By now, I have amassed a large number of cereal sized bisqued bowl for the next stage of glaze testing.  I will also throw a bunch more of the small bowls I used this time (wheel thrown from 12 ounces of clay), which proved an excellent size for testing glaze combos, even with the smaller (e.g., 500 gram) glaze quantities.   My head is exploding with ideas, and I finally have some REAL finished pots!  Very exciting!

 

I’m back!

Recently this blog has more resembled “Miri’s Pottery Prattle” than “Nick and Miri’s PR Prattle” and for that I’m afraid you must blame the Wimbledon Tennis Championships.

For the last 2 weeks I’ve been ‘busy’ lounging on the sofa watching hours upon hours of fantastic tennis, thus letting Miri monopolize blog proceedings!

Alas, it all ended today (with Roger Federer winning a record breaking 15th slam in an epic 16-14 fifth set win over Andy Roddick) and so I am back in the blogosphere, although I’ve nothing of substance to report (see above re. extended period of sofa dwelling).

I will leave you with a picture of Maria Sharapova. She didn’t do anything of note in this year’s championships, but hey, I don’t need a reason to post a picture of the lovely Maria!

 

PVC Magic Take 2 – Kiln Shelf Storage

A trip to Home Depot always means figuring out what other future projects might need parts.  Before we headed out to buy all the bits and pieces for the light box, Nick and I pondered another little problem we were trying to solve on the pottery front.

Problem:

Between firings, I’ve been storing my kiln shelves (other than the bottom two, which stay in the kiln) by precariously leaning them against the wall by the kiln.  No es bueno.

Nick’s Solution:

Using PVC (and some casters we happened to have), Nick created a rolling, easy to clean and very sturdy shelf rack.  Nifty, if I do say so myself!  Here is set up in situ:

 

PVC Magic Take 1 – Light Box

As the saying goes, you only get one chance to make a first impression.  This truism holds  for pottery and it is therefore important to me that my photos of my pottery are as strong as they can be.  I read with interest Jeff Campana’s comprehensive post about how he creates digital images of his amazing pots.  One of the main take-away messages?  Get a light box!

After dead-ends on the online purchase front with the cheaper light boxes (around $40), we decided to build our own light box for photographing my work.  I found a LOT of information online about DIY light boxes but was sold once I came across one that involved using PVC.  We have a lot of pipes hanging around, leftovers from construction, and Nick LOVES to build stuff from PVC.  A trip to Home Depot (and  Kmart) and we had all our parts:

For less than $10, we had the makings of my light box AND the makings of a frame for mounting the lamps (missing from the photo is the white sheet of poster board we purchased at Kmart and a hanger we used to attach it to the frame).  The light fixtures and bulbs were the big expense (and we would have had to have purchsed them regardless), coming in at about $20.  Here is the frame of the box and the frame for mounting the lights:

Lights off…

Lights on!

For diffusing the light, we used a fitted twin sized white sheet.  Here is the final set-up:

Classy, huh??  :-)  Well, regardless of how it may look, the setup does seem to do the job.  As Jeff suggested, it seems that the most important thing is getting the light right.  We’re still messing around with light angles and distance from the box to get the best photos.  Since none of the joints are glued we can easily expand the setup.  For example, we have another  longer 1/2inch pipe for the external light frame so we can set the lights further away from the frame.  I tested the box out with a bowl I made in the UK that has been quite a pain to photograph (lots of shiny reflective surfaces):

Not a bad start, huh?

 

There will now be a short delay…

I started taking pictures of my new pots and decided I really NEEDED a light box!  I looked at ebay, saw some that looked good (about $40) but the sellers either didn’t ship to Puerto Rico OR wouldn’t specify how much shipping to PR WAS (just that it was MORE).  Sod that!

A quick search online uncovered many DIY designs for light boxes, including some that suggested using PVC.  Joy oh joy!  My love of PVC is only matched by Nick’s love of that delightful material (and the wonderful aisle in Home Depot filled with lots of excellent little PVC parts).  We had all the PVC pipe we would need leftover from construction but needed a few cruicial parts (including the light fixtures) to complete the set-up so off we went to Home Depot.  We are almost done and glaze results are forthcoming, as is the description of Nick’s PVC masterpieces!  :-)  Happy Independence day everyone!

 

No lizards were harmed in the making of this pottery

Whew! We’ve unloaded the kiln and boy are there some fine results. Most importantly, lots of great learnings and direction for mixing up larger batches of glaze for future work (and NOTHING ran!!!).  I’ll post a much longer report of the glazes I used and my results but for now, here’s one of my favorite glaze combos (variegated blue over licorice black):

Here is the top of the loaded glaze kiln pre firing:

And for the “after”, as well as blog history, here is the momentous opening of the kiln:

P.S.  There is ONE difference between the pre and post top shelves (other than the firing of course!).  Can you find it???

 

Lessons in self control

 

Going down…

***WARNING!  The following content is likely to bore non-potters to tears***

Well, for what’s its worth, my very first glaze firing (this is a test, this is ONLY a test) is almost under my belt.  Amazingly, everything fit!  I am following the firing schedule suggested by John Hesselberth and Ron Roy. The trick is that, having never fired to cone 6 in my kiln, I had no idea what temperature to set it to so that I could include the recommended soak (i.e, not have to skip the soak and start the cool down when I hit temperature). In my quest to figure out how to fire my first cone 6 firing, I found this very helpful exchange on Clayart:

On Jul 25, 2005, at 1:40 PM, Charanjiv Sachar wrote:

> Should it be such that Cone 6 should bend at the end of the 20 minute
> soak?
> I know it will take a few firings to program it the way the cones
> should bend. But when should Cone 6 bend? or it doesn’t matter and it
> is a matter of how I want the glaze to look?
> I might have just answered my question.
> Thanks in advance to everyone
> Charan

Hi Charan,

Unfortunately there is no fixed answer to your question. Every kiln is
a little different and thermocouples drift a bit as they age. With my
kilns I find somewhere between 2170 and 2195 usually does the trick.
But when I am firing with a new thermocouple or in a kiln I am not
familiar with I pick a temperature at the upper end of that range. Then
I watch the witness cones and when cone 6 gets to about 2 o’clock I
note the temperature, turn the kiln off and quickly enter a new program
that has that temperature as the peak, the soak I want, and the cooling
cycle. Then turn the kiln back on. It shouldn’t take more that 2-3
minutes and the kiln won’t drop more than 15-20 degrees. Then if the
cone bends to almost tip touching during the soak I just use the ’skip
to the next ramp’ capability of the controller and start cooling a
little early. All this just requires you be thoroughly familiar with
how to program your computer–but that’s not such a bad thing to learn.

Then in future firings you will be much closer and, gradually, you will
get your program fine tuned to where the computer does the whole job.
You will have to adjust it a bit, though, every few firings as your
thermocouples age. Good luck.

Regards,

John
John Hesselberth
http://www.frogpondpottery.com
http://www.masteringglazes.com

Following John’s advice, I set the target temperature on my program to 2195.  I also programmed a second program, with a “full steam ahead” (9999) ramp up to 2185, with the required soak, then the controlled cooling ramps.  Knowing how anxious (and sleep-deprived) I’d probably be during the firing, I figured it would be quicker to change just one number in the program when the time came rather than enter the whole thing.

I started looking at my cones at around 2100F.  At 2145F, Cone 5 (my guide cone) reached 1 o’clock.  It hit 2 o’clock around 2160F, then finally 3 o’clock at 2165F.  At this point, Cone 6 started to move.  It reached 2 o’clock at 2178F, at which point I stopped the program, and quickly re-programmed my second program with 2178 as the peak temperature.  Whew!  A few minutes before the end of the soak, Cone 6 had it’s tip touching, with slight movement starting on Cone 7 (my guard cone).  This is what is described in “Mastering Cone 6″.  I skipped to the next ramp. So far, so good.

Now, the kiln is going through its controlled cool down (free fall to 1900F, then 125F an hour to 1400F).  I have never been so excited nor terrified about a kiln firing before!  Hopefully there will be a few nice results.   Stay tuned…

 

Going up….

Oh boy oh boy oh boy!

 

Variegated. Not talking glazes now.

Yesterday, after a looooong day of glazing for me and a loooooong day of watching Wimbeldon for Nick, Nick suggested we head to the beach for an evening walk, followed by beers and pizza at Pepe’s, probably our favorite spot in Rincon. Fine idea!

During our walk, from a distance, I noticed some seemingly variegated sea-grape plants. I’ve never seen this plant with partially white leaves, so was quite curious and approached for a closer look:

In close proximity, we noticed a “variagated” unhealthy looking coconut palm…hmmm! The plot thickens!

On our walk back, the mystery plant “disease” source was revealed: A flock of hundreds of pelicans roosted in a large tree. We’re glad that they, unlike us, didn’t decide to live up in the hills!

 

Test Glazing? Done!

• 10 small bowls
• 2 “infinity” vases
• 33 “proper” test tiles
• 19 espresso cups
• 32 small plates/saucers
• 9 shell pendants
• 12 round stamped disks (magnets)

Whew!

I’ve got kiln-washed “biscuits” to put under everything in case glazes run.  And, my kiln shelves have 3 coats of kiln wash, fired on. Hey, got to be prepared for what might be the reality of my first firing…  Hopefully, I’ll got a least a few cool results.

 

Simply beautiful

There is something so alien but so beautiful about a banana flower. I discovered this beauty right next to my new vegetable patch while on a break from finally getting my vegetable plants (cabbage, cucumbers, eggplant, 3 types of peppers and pumpkin) into their new home (more on that later). Stunning, no?

On the glazing front, things are progressing, albeit slowly. I’m discovering that glazing small things takes just as long as glazing big things and boy do I have A LOT of itty bitty pots! It doesn’t help that I’m trying to be “clever” with my new glazes but oh well, its all good fun, regardless of the outcome. This is a glaze TEST firing after all, right?

P.S. Jim and Gary, the glazing table is getting messy now!

 

Glazes? Check!

 

Mixing glazes is a lot of work!

I’ve been down in my glaze/kiln room mixing up glazes. For those of you unfamiliar with the process, glazes are made by combining together chemicals that, when fired, create glass (silica), stiffen the glaze so it doesn’t slide off the clay (alumina) and cause the glaze to melt at a low enough temperature to be used in ceramics (flux). Glazes may also include other additives such as opacifiers, suspenders (so the glaze doesn’t harden into a lump in your bucket) and colorants (such as cobalt, copper).

The actual mixing involves following a recipe that outlines the exact components of the glaze, with specific quantiatities. Some glazes serve as a base glaze, to which can then add various materials (done mostly to change the color of the glaze). Such glazes offer plenty of room for experimentation to come up with unique colors and surfaces. Yes, you could just buy pre-mixed glazes, but then you could also buy tv dinners!

I was planning to mix up about 6 glazes but ended up with…11 (ranging in quantity from 200 grams to 1000 grams depending on degree of experimentation…). Regardless of batch size, the process is the same: measure out the dry materials, mix, add the dry materials into water, mix, then run through a sieve (80 mesh) twice! After spending all day hard at work, I’ve finished two glazes, with 9 more to sieve. Once all the glazes are sieved, I finally get to glaze some stuff! But now, this is where I am heading, at least until its gardening time…