Mars (Martianware) clay, finally fired

Mars clay bulbs with small impressions (left) and flower stamp impressions (right)

I finally got around to firing some of the pieces I made last month with the new Martianware clay. In fact, I fired them a while ago and only just got around to taking pictures this weekend after my most recent glaze firing was completed.

Salty Mars covids and bulbs before firing

Since I wasn't sure about the clay, I didn't make a lot of items with it. Then, before firing I got concerned about the salts damagining my kiln walls or elements. The soluble salts show up on the oustside of the forms as the clay dries, and they also act like glaze mixed into the clay, creating the unusually texture surface. Firing a salt kiln can be hard on the walls and the elements. Though this was clearly a lot less salt than a salt kiln, I decided to play it safe and make some saggars in which to fire the work.

Saggars after firing

I threw and slab-built four saggars which I can reuse in future. Being extra cautious, I also fired the pieces on stilts which was probably unecessary, as it turned out. Based on how the saggars look inside after firing, I'm guessing these were unecessary, too. The floors of the saggars have a bit of spitting, little freckles of color, but the tops look just like the outsides, no damage.

 

Interior of a thrown saggar with salt speckling from the Mars clay

I fired the pieces in a bisque firing with a bunch of other greenware. This Martianware clay isn't supposed to get too hot. This bisque was cone 06 and fairly full. The Martianware ceramic surfaces have varied colors ranging from brown to red and a rough, crumbly texture. I can't tell how much their location during firing or drying or their building techniques impacted the colors, so I'll have to pay closer attention next time.

Mars clay Covid Balls

The surfaces feel crumbly, as is evident in some of the pictures where there are little dustings of crumbs that I didn't brush away. The bits that do flake off don't stain my photo paper and removing them from the surface doesn't seem to impact the colors of the original form. I haven't tried scrubbing these pieces yet, but they feel like raku work that needs to have the ash washed off.

Mars clay bulb (other side)

 

For a few of the pieces, I mixed the Martianware clay with my regular pugged reclaim and the result was underwhelming. Theese pieces just look like a bit of terracott has gotten into or onto the regular clay which looks white after bisque.

Mars and reclaimed clay Covid balls after bisque

In one case, as a test, I glazed the rest of the form (the part made of reclaimed clay) and left the inset Martainware clay circles unglazed. I then fired the piece to cone 6. As expected, the clay fluxed and bubbled a bit. I knew the clay wasn't designed for this temperature, but I was just curious what would happen. 

The black dots are actually the Mars clay fired to cone 6. The lines and yellow surface are glazed

I made COVID balls and Ericano bulbs out of the the Martinaware clay. On the COVID balls, I didn't do much to the surface, relying on the clay itself to create texture. For the bulbs I tried a few different things: sprigs, impressed stamps and a texture roller/stamp. The impressions look pretty similar after firing, as the clay sort of takes over and obscures the texture. The sprig additions are easier to see on one side than the other, based on the clay color and how it shows up differently in the higher and lower areas.

The front and back sides of the sprigged bulb made with Mars clay

The clay is fun, but working with something like this requires a really different planning process, especially for someone who is used to focusing on texture and color. I could see this clay working well for the darker, moodier work I did for my politics bulbs series, but I'd have to think about what can and cannot show up as far as texture. This clay could lend a gritty feel, but it could also obscured what I want to show. And, honestly, I've felt a bit exhausted in thinking about this work lately. 

Mars Covid ball

This past week I was a bit disappointed in my kiln results, which tends to be opposite of a motivator. But while I was photographing the work I realized that I had quite a bit of work. Some of it disappointing, but at least I've been making. Some loads are like that.

Mount St. Helens Glazing

my mixed ash/low fire glaze ready to fire

Early this winter I was invited to make some work for a Mount St. Helens art show. The show date and location have been shifted to account for the pandemic. I was given a new deadline of last Wednesday which I have now missed. I don't very often miss deadlines like this. I think that with the spring quarter moving online, the general worries about the pandemic, and the specific anxiety of trying to work from home while my daughter is also home all day, I had reached a point of just not being able to make everything work.

bisque with two volcanos and some sprigs, ready to unload

I did get the work made and bisque fired by last week's deadline, but pure white wasn't really the look I was going for. I still have some serious uncertainty about the end results, but I glazed this weekend and I'm just about ready to fire the pieces. 

Mount St. Helens eruption box ready to fire

The reason I am uncertain is that I made a significant mistake when I began this project. I was anticipating being able to use some Mount St. Helens ash glaze made by some fellow artists, and though I knew this was cone 6 glaze, I started building with cone 06 clay. 

cinnamon underglaze on interiors and some box exteriors

I had the low fire clay out to make a batch of sprigs and I simply didn't think before starting to build. I'm going to chalk it up to trying to squeeze in too much thought into my week. Usually I work on projects in the summer when I'm not teaching. Occasionally I work on projects during breaks or on the weekend during the year. I can honestly say that I've never worked on ceramic projects during a pandemic while trying to adjust to a fully online quarter and preparing for contract bargaining as president of our faculty union while my daughter is also home with me all day, every day. My brain was (is) full. I couldn't cope.

my three glaze tests at cone 06

Since the work was made in low fire clay, I can't fire it to the higher cone 6 temperature without risking damage to the form. I also couldn't remake before the deadline, so I figured I should try some glaze experiments during my bisque firing. I had the cone 6 glaze, which I guessed was highly unlikely to melt at cone 06, but I figured I should test it anyway. I also tested a glaze that mixed one part of the cone 6 ash glaze with one part of a cone 06 gloss glaze. The third glaze I tested was equal parts ash and 06 glazes with some added red iron oxide. I used the sophisticated technique I learned in graduate school from my checked-out ceramics professor: scooping a random amount so that the results can never be replicated (see above re: no more brain space).

glazing and under glazing in progress

The results weren't particularly surprising. The Mount St. Helens ash glaze on its own didn't melt at all at cone 06. Cone 6 is roughly 2165 - 2232 degrees Fahrenheit, while cone 06 is only 1798 - 1828 (Cones melt based on time and temperature, so the range refers to a slower or faster firing), so the difference is significant. The mixed glazes also didn't melt correctly--again, not surprising. But the mixed glaze fluxed a bit, meaning the surface is starting to become glossy, and has a thick, semi-opaque texture. This texture reminds me a bit of lava, which seems fitting for this project.

peeling off the resist

Because I really want to use Mount St. Helens ash (pumice) in the finishing of these pieces, I'm happy to see what happens with minimal testing. If I were going to fire these pieces, as originally planned, to cone 6, I have a variety of colored glazes that I was planning to use. For cone 06, I have clear glaze in matte or gloss. So, I have used some of my underglazes to try to add some interest to the forms. 

glazing in progress

Did I take pictures of my work after I had finished adding the underglaze? Of course not. Thinking and planning are apparently not things I do anymore. Nor, according to the images shared here, do I take care to check that my images are in-focus, so this is what I've got. Done is better than perfect (I mean, assuming perfect isn't done, right?)

applying the Duncan Mask & Peel to the lid 

I used cinnamon underglaze for the interiors of all the pieces, as well as for a wash on the textured surface of the eruption and venting. I usually like to layer two colors of underglaze over each other, but I simply didn't leave myself enough time for this project, so this will have to do. 

I put a clear glaze over the underglaze on the interior of each piece, so the color looks pink (or white) before firing

Usually when I layer underglazes, I fire them in between, which means I can wipe the surface after adding the glaze. Since I didn't have that middle step, I used some resist which protects the underglaze from accidental drips of glaze and then can be peeled off before firing, taking the over glazed mistakes with it.

this box has both types of glaze on the outside. We'll see how it looks when I unload it.

I used underglazes alone in in combination for all of the pieces, but also left the bare clay color visible in several. I am concerned about how this will work, but time is passing and these are past due. I used a gloss glaze over the cinnamon underglaze inside every piece, then used a combination of my low fire glaze and the mixed ash/low fire glaze for the exteriors, leaving one without any exterior glaze for contrast. The underglazes I use are velvets, so they tend to look nice without a glaze anyway.

Ninja Junior Crawl

Lidded Jar by Adela Arciga. The Ninja Junior Crawl Glaze is used only on the lid, where it was applied over a copper/cobalt glaze that caused it to melt.

The quarter ended last week with final critiques and final photos of work. In my clay classes the last week before finals are spent glazing and firing kilns, so that by the end of the week most students are done working and are just waiting on kilns. I also have them all take photographs of their work on a nice clean backdrop and put them in a folder shared with me. The work looks so much better on a backdrop and I like them to get the practice of taking good quality photos of their work. Even if they never do pottery again, they have this record of what they made. All the photos shared in this blog were taken by the students themselves (I did crop some of the students' photos).

Mug by Amber Ryan. Ninja Junior Crawl was applied over a cobalt glaze that doesn't run or flow too much. The dark spots on the side and handle are where the NJC glaze fell off before firing.

This quarter's wheel and hand-building classes were particularly strong. One indication of this was that all students had all but two of their works glazed and finished on time for their last critique. This probably shouldn't be a surprise, but it isn't unusual for hand-building projects to break before or during firing and it isn't unusual to have a few students who just don't get their work glazed in time to be fired, or at all.

Lidded Jar by Lauren Coffey. Ninja Junior was applied on the lid over a  fairly think coat of a semi-transparent glaze.

This quarter I was firing lots of kiln loads at the end of the quarter, but I didn't have really any abandoned student work to deal with after finals were over, meaning the students either took their work home, loaned for the Spring Student show, or donated it to the studio. On the other side of the equation, both final critiques were lots of fun and the students had great work. 

Bowl by Amber Ryan. This bowl has NJC only on the bottom, again over the blue glaze she used on the mug above.

In the throwing class in particular, there were some trends I noticed as far as the forms students chose to make. I'm not sure if a glaze choice can be a trend, exactly, but during their final critique my throwers spent a lot of time discussing our Ninja Junior Crawl glaze. This is a glaze recipe I developed in graduate school and brought to the YVC studio during my second year (while I was heavily pregnant). It was named after my daughter's tendency to kick fairly hard before she was born. I remember throwing for class one day and she kicked so hard she moved my arm.

Tiny bowl by Taelynn Loyd with just NJC

The conversation during the critique focused on students' preferred methods of applying the glaze. Ninja Junior is a crawl glaze, meaning it is designed to have some thickness and pull away from itself (or crawl) on the surface of the pot. When applied alone, as in Taelynn's tiny bowl above, it has a matte texture and cracks in the surface. The edges are linear and the edges can start to peel upwards. With thick applications, it can fall off before firing, or even peel up so far during firing that it barely seems attached. If it is applied excessively thickly, it can start to melt, but it will still pull away into separate pieces.

Lidded Jar by Lauren Coffey with NJC on the lid over a runny copper glaze

When this glaze is applied over another glaze, the other glaze can impact the texture and the shape of the NJC glaze. The reaction of the two glazes together lowers the melting point of the combination. This is sometimes called eutectics. A glaze that melts during firing, but retains a more satin texture will cause Ninja Junior Crawl glaze to also melt a bit, rounding out or flattening the individual sections of the NJC glaze over the top. A glaze that melts to a high gloss finish and also moves on the surface of the pot when in the kiln will cause NJC to start to move and mix with the gloss glaze during firing. In the images shared here, the dark blue glaze melts the least. The red glaze melts the most.

Bowl by Taelynn Loyd

Of course the thickness of the Ninja Junior Crawl glaze also matters. In Taelynn's bowl above, she applied the blue fairly thin, but the NJC is fairly thick, causing it to look different from both of Amber's examples earlier in the post. The NJC on blue in Taelynn's bowl is divided into large glossy blobs, whereas Amber's mugs and bowl with the same blue glaze show smaller and more geometric divisions of the NJC, mostly because NJC was applied thinner.

Underside of bowl by Beau Filbert

Beau Filbert created a thick texture with several glazes, simply based on his application. In the bowl above, he applied a Copper Red glaze, which melted enough to create even drips all the way around, but not enough to drip onto the shelf. He used a think coat of Ninja Junior Crawl on the rim. Though is is a thin coat applied in a small area, we can see how it acts differently on its own and over the copper glaze.

Mugs by Beau Filbert

Beau did lots of experimentation with drips on the sides of both bowls and mugs. In the photo above, the mug on the far right has drips that similarly get thick at the bottom but don't melt off the piece. This glaze combination does not involve NJC.

Loading Lots of Kilns for Class (and Back Pain)

Egyptian inspired sarcophagus and coil vase by Isabella Johnson, before glaze firing.

I have three strong clay classes this quarter. The hand-builders I've written about once this quarter, and when I get my act together, I share some more of their work from this quarter. The wheel class is unusual in that the class started full and ended full. Most quarters, a few students drop after the first day or two, once they realize what the class is about. I'm not sure if they go away because they find it too difficult, their schedule changes, or they don't want to get dirty, or maybe there's something I'm doing that they dislike. I usually lose these students so early that I try not to take it personally.

Wheel thrown mug by Beau Filbert, the pink glaze was misbehaving that day.

This quarter I have 16 throwers total in the beginning level functional pottery and the advanced wheel classes, which meet at the same time. The students laughed at me the first time I said we would need to hurry through critique because the class was so large. They're used to thinking of 35 students as a large class, not 16. (I enjoy working at a college where a large class is 35, not 100) With 16 student wheels, that's the most I can fit in a class without some kind of wheel rotation schedule (I like the pun, I'm leaving it in).

One of four full carts of finished work this week. This batch was unloaded from the cone 10 reduction firing.

Last week was the last week of classes, with three days of finals next week. The last week is often crunch time for firing and finishing work, but the crunch gets worse (or better) with more students, especially when those students have more work. Since all three classes this quarter are composed mainly of hard-working, motivated students that just means there's more work to fire. 

a look into one of the oxidation firings as I was unloading it. Just one real drippy piece.

Monday was meant to be our last bisque firing, but with both bisque kilns completely stuffed, we ended up needing to fire again once those were unloaded. In fact, we ended up firing two more loads. On Wednesday we unloaded the super last final (really, I mean it) load and then later that day the super uper duper last (now I really mean it) bisque loads. Because so much wasn't bisque fired on schedule, we didn't have a chance to fire our gas kiln (cone 10 reduction) twice last week and only fired it on Thursday. 

This little bird on above the handle really caught my eye as I was unloading. I'm not sure whose work it is.

I had started having some back pain the week before, but I figured I just overdid it at boot camp or maybe had been sitting at a desk too much. My usual response is to walk or stretch or exercise it away. I also haven't really had back paint before. But by the end of the day Wednesday my back was really hurting and though I'm still not sure about the initial injury, I think the kiln loading exacerbated the pain. It probably didn't help that I was unloading hot kilns and that the one kiln is very deep.

I might have hurt my back trying to lift this big girl.

Because of the late bisques and late gas firing, after the "super last" bisque loads were done on Thursday, we needed to load the equivalent of more than a full gas kiln load in the electric kilns. The hand-builder critique is on Monday morning, so I knew I needed to get their work into the kiln last week. I mostly unloaded and loaded both kilns (all four loads) myself because students were glazing, one of my studio assistants was ill, and the other had to leave early. I usually load with more help, so that I might lift out the heavy shelves from the large kiln, but then hand them over to someone else. 

Isabella's Sarcophagus and vase after firing. Some thrown work and a woman's head are also visible.

I loaded these kilns carefully, since the hand-builders' work tended to be fairly large. In the large kiln, I put in the tall work at the bottom, but there were a couple of pieces that weren't ready when I loaded the bottom of that kiln. I saved room at the top of the smaller kiln and loaded the remaining large pieces as soon as the student finished glazing. Since throwers don't critique until Wednesday afternoon, I figured I could load and fire the remaining cone 10 work on Monday/Tuesday.

Here's something unusual that we found when unloading one of the last bisque loads. This foot had popped off an inside was some crumbly white material that felt a bit like styrofoam. If you look closely, you can see the shape of the foreign object that got lost in the clay.

My back was starting to hurt pretty bad, so I was relieved not to have to unload and load again without help. (On Monday I should have plenty of support from students and work studies and assistants.) Then, I walked out of the kiln room and looked on one of the work tables. There were two hand-builder sculptures glazed, ready to be loaded, but not on the glazed work shelf. I could tell they were meant to be loaded, and one of them was very tall. It wouldn't fit in either kiln without unloading a serious amount of work. 

We think that a silicon end of a "rubber tip" blending tool fell off, got lost in the recycled clay, then turned up in the middle of the student's clay slab. Since it was small, she didn't notice it until it caused problems with the fired ceramic piece.

So, that is the story of how I ended up coming in on Saturday (with a sore back) to unload two full electric kiln loads and then reload two full electric kiln loads so that all the work could be ready by Monday's critique. (I neglected to mention that I also needed to fire a low fire kiln load with hand-builder work, but there were only about 6 items so that load was pretty small and easy to load--once I had unloaded the cone 10 stuff). I anticipate a fun, interesting critique tomorrow. And no more kiln loading for me until next quarter.

Underglazing for Art a Day Project

a coat of wet terra-cotta under-glaze on the screaming face, before wiping

I finished the building for my Art a Day projects early last week and have been glazing since then. Right now I have 50 pieces in the cooling kiln and the rest are being glazed today. 

abstract and politics bulbs used different clays

I made the two sets of 30 from two different kinds of clay. The abstract bulbs are made with a reclaimed stoneware from last summer and the others are made with a red mica clay that I thought was similar to the clay I used for last year's political bulbs.

the new mica clay and the old political bulb clay

As it turns out, the new clay is much lighter in color and more sparkly than the clay I had last year. They look the same in the bag, but last year's clay was a gift and I didn't replace it with the same type. My intent was to keep the tone of these political bulbs much darker than the bright layered colors of the abstract bulbs. Last year I did this, but I also had some issues with last year's clay looking splotchy. It may have been because I wasn't as careful as I should have been about getting light clay on the dark clay because I was working the same space or with the same tools. 

the new red mica clay with under-glaze inlay at cone 04

I also wanted to use a clay that is pretty itself because, unlike most of my work, I didn't plan to cover it all with underglaze color. The mica in this particular clay causes little sparkles to be seen on the fired clay surface. I wanted to use the colored underglazes and shiny glaze solely to highlight the textures, lines, and impressed letters of the finished pieces and let the dark, sparkly clay also be visible.

the new red mica clay at cone 08 (left) and cone 04 (right)

I initially bisque fired all the pieces to about cone 08. I was impatient and wanted to go to bed with the kiln off, so I shut off the kiln a bit earlier than scheduled. I was disappointed in the very light orange color of the mica clay at this low temperature. In the second firing I had a mixture of greenware to be bisque fired, some underglazed abstract pieces and a couple of glaze tests, so I fired to cone 04. The mica clay looks much nicer at this temperature.

bulbs and sprigs waiting to come out of the bisque kiln

I was given a bottle of clear glaze in a brand I don't normally use, so I wanted to test it on the new mica clay before applying it to the finished pieces. Immediately after bisque firing (at either temperature), the political pieces are clearly distinct from the abstract pieces. I tried to apply color and glaze differently, too. However, during building, some of the content started to bleed across the edges of the two groups as I worked. I ended up with faces, eyes, and hands done in both white and red clays and some of the pieces I made with white clay could probably fit in with the political group.

each bulb needs three coats of underglaze, so some are drying while others away their first coat  

All of the abstract bulbs required two layers of underglaze. I used mostly highly textured surfaces and I enjoy layering the underglazes one over the other. In most cases, I applied one color to the background texture, a contrasting color to the sprigged additions, and sometimes another color to highlight a dot or contrasting part of the sprig. 

two sets of bulbs with one or two underglaze layers waiting to be glazed

After this first layer(s) of underglaze, I fired all of the abstract pieces again. After the work came out of this second firing, I applied a second coat to most of the abstract pieces, then wiped it away incompletely. The fired first coat stays put when I wipe away the second color from the raised surfaces. This approach highlights the textures, because one color is visible in the deeper recesses of the texture or sprig and another color is visible everywhere else. Most of the abstract bulbs have 2-4 different colors of under-glaze, some have 5 or 6.

political bulbs and one "abstract" face with under-glaze waiting to be wiped

Because of when I finished building, I had some newly dry work to bisque fire as well as some abstract bulbs with one layer of under-glaze. I also fired some of the political bulbs with a wiped coat of under-glaze inlaid into the textures to see the mica clay color at that slightly higher temperature at to determine whether I needed glaze in addition to underglaze in the impressed texture areas.

a political bulb on top of some abstract bulbs, all have had the underglaze layer applied and wiped and are waiting for glaze

After I applied underglaze, re-fired, reapplied underglaze, and wiped the surfaces, in most cases I also applied a clear glaze to the surface. In the political pieces I will probably use a combination of fired underglaze with glaze and without. The underglazes I use are mostly Amaco Velvets which have a nice of a texture on their own, and at least one of my colors fluxes by itself at cone 04. 

under-glazed and wiped politics bulbs waiting for glaze

In a few cases, I added under-glaze color and/or clear glaze over whole sections of the political pieces to try to accentuate the subject and make it more recognizable. In one case I felt the MAGA hat just needed to be red, in the other case I felt the ice (ICE) needed to be glossy in contrast the the bulb out of which it projects. I used a satin clear glaze one the ice and the underglaze alone on the hat. The kiln is over 1000 degrees Fahrenheit now, so I won't be able to see my results until tonight or tomorrow.

clear satin glaze covers the ice cubes in "Melt ICE"