Marcia Selsor

I've taken to using the web between the pointer finger and the next finger to compress lips. No extra reaching!
 
best,
Pres

Porcelain tends to fuse to itself during the glaze firing. Sometimes the feet also fuse to the kiln shelf. So using Alumina prevents both of these things from happening.
 
Marcia

I have used alumina in wax on porcelain for many years and never saw anything like that. I usually just brush is one both sides and the bottom for porcelain.
I can only think that it may have dripped during application. Was your wax white?
For that process, I use the Aftosa wax.
I like it because it is bluish and can be seen. It can come off if you make a mistake and catch it immediately.
Marcia

Moved.
Good catch! You'll be much happier with the new elements.
New kilns and old kilns only differ in cost of firing if they have different brick thickness. 2.5" brick used to be the standard on older kilns, with the exception of 28" wide kilns. Now 3" is the standard on all sizes for the most part. Some manufacturers don't even offer 2.5" brick any more.
I once did a test to see how much firing costs change as elements wear. I let the elements in my L&L e18T-3 wear until they could no longer reach cone 6, and the firing cost was double that of a new set of elements. On my kiln that was an extra $9 per firing. In a 10 cubic foot kiln it could be $25 per firing. So definitely keep those elements fresh. Once the resistance has changed by 10% from new they are due for changing. A cheap multi-meter is definitely worth the investment to be able to check element resistance every now and then.

A while back I mentioned on my Workshops Facebook group that my large Skutt kiln cost a small fortune in electricity to fire and that a newer kiln wouldn't have that issue.  Which turns out to be true - in a simplified way.   A long firing using my Skutt after 20 years was taking too long and eating a lot of power.   It might run me $50 in electricity to do a single long, slow firing and that's nuts. I had no idea until my husband commented on how much our power bill had jumped up when I started using that kiln again.   But for a while I had used this kiln so little until the past year that I forgot how long the firing schedule should have been.

While firing a Cybis 'Nashua' I've been working on for a while, one evening my kiln finally threw an error code and aborted the firing.  Thankfully my client's Cybis wasn't ruined.  It merely didn't fire up to temperature.  Either one of my kiln elements had blown or my thermocouple had gone bad.  Testing was in order.  A simple multimeter (while the power was disconnected) showed me a LOT of resistance in the elements that still worked.  I then ordered new elements for my Skutt and they arrived yesterday!  Mind you, BOTH of my kilns have been used much of the past 20 YEARS and NEVER had anything replaced on them until last year.   My Skutt especially still looks brand new and I try to keep both kilns in top condition, but....  My Olympic suddenly blew a relay last year and that was a wake up call for me!  Now this.

Needless to say I should have replaced the relays and elements YEARS ago.  Expensive as they are I've surely wasted several times the cost in electricity in just the past few years due to having worn out elements and not realizing it.   All my firings have continued to go just fine - I just wasn't keeping a log of how long it took for those firings.  If I had been I'd have seen that my firing times were getting longer and longer over the years.  It did that so slowly I didn't even notice.  I barely even use this large Skutt kiln compared to my little Olympic Doll E so why would I have caught that?  Now I feel stupid for not catching it sooner.
As I am fond of saying, 'No matter how much you think you know about anything, there is ALWAYS more to learn!'  Ceramics is definitely no exception to that rule.  So guess what I am doing today?   Replacing all four elements in my Skutt.  I've got this!  There's a YouTube video for almost anything out there...
 

Doug Baldwin , long time educator at the Maryland Institute College of Art in Baltimore, passed away in Dec 2018 also. Below is the piece from MICA newsletter as it appeared on the NCECA blog. Doug was born in Missoula, Montana and retired to Missoula. He continued working at the Clay Studio in Missoula.
Marcia
http://blog.nceca.net/remembering-doug-baldwin-1939-2018
 

Eve marie Gibbons died last month. She was a member of Clayart many years ago. More recently she was teaching post -fire surface finishes on Teachinart.com. Her death was very unexpected. 
Marcia

Duly noted.
Pres

There have been times where a significant event has happened involving ceramics where posters could not figure where to post it. Sadly enough, deaths of important artists is one of these areas. There are times also when a major museum has a Ceramics event of great interest, or where some other event occurs that really should be posted other than in the Ceramic Events of Interest area. We have posted this strand here in the Educational Approaches and Resources section as we expect the litmus test to be. . . .is this of educational importance to Ceramics.
 
best,
Pres

Last week we explored a little about feet on vertical forms, and alluded to the importance of lips on vertical forms, mugs, cups, pitchers, vases etc.
Which of the following profiles would you attribute to you forms? Do you use more than one profile, or do you have a profile that is not listed here as in 7.
I think most of us started out with something like 1 or 2, when beginning to throw, and often maybe felt that wasn't enough and went to 4 or 5. Just my thoughts.
QotW: How do you finish the lips of you vertical pieces? Please explain, and provide pictures if needed.
best,
Pres

I have used similar products frequently with stains and glazes.  As @Chillystates not great for overall glazing, but useful in many ways. I you have highly textured surfaces you may use stain or glaze at angles across a piece to accent the texture. These work well over a base coat of glaze, dipped or sprayed on. At the same time the slow build up of color over texture will show many variations of depth in the surface. The latest slab/wheel combination piece in my galleries is an example of a highly textured slab surface with cobalt and iron stains applied first, painted and sponged glaze added on second, and thirdly a series of sprayed on glazes that I was not familiar with only using test tile references to build up the surface. Load the image into an edit program an look at it closely. . . . you may be surprised.
 
best,
Pres

I was going thru downsizing old Ceramics Monthly's yesterday -the 60s and 70,s issues-kept a few 70s glaze recipes rest hit the recycle bin
I found this ad in the October 1970 issue-My Model C is that wheel assembled it was $265-splash pan was galvanized sheet steel. The thing to note was the flat formica decks and the foot pedal those are the two features that they changed fairly quickly in early 70s.  The other features that changed soon afterwards where 3/4 shafts on all wheels (these where 5/8 inch) and motors that had easy change brushes on the outside of motor. This ad also notes the location in Santa Monica that I bought my wheel from Brent himself-which was 1970.
Brent moved shortly afterwards to Healdsburg Ca.. I met recently a woman who's husband worked there back in the mid 70s. Small world
 

Besides the obvious issue with firing large slabs flat (dunting), the other issue is uneven heat. The side exposed to ambient kiln temperature can vary to the temperature under the slab in direct contact with the shelf; further adding to the warp issue. I have fire porcelain slabs up to 30” square by bisq firing them on edge. Use tile setters as shown, or prop them up using other wares. 
Tom

I think it is copper too. In an alkaline base
Marcia

I think it is copper too. In an alkaline base
Marcia

I use stencil paper, what I would call a thin cardboard like binder dividers. I cut the image or pattern with exact knife

Just a few drops of dish detergent worked into brush bristles.
 
 

Just a few drops of dish detergent worked into brush bristles.
 
 

I use stencil paper, what I would call a thin cardboard like binder dividers. I cut the image or pattern with exact knife

Lately I have been using the stencils, stamps and branches etc directly on the slab after rolling, actually embedding into the slab a design. In the slab piece here, I used a large slab, decorated completely then cut to slabs for use so the design went around the piece. After bisque, cobalt and iron stains were used under the glaze,  
Glazing was completed using dipping, pouring and atomizing layers of opaque, and transparent glazes to build up the surface.
best,
Pres

Research majolica glazes and Linda Arbuckle, she is the best.

Picture below has been cropped to fit format: actual clay size is 7” x 4” x 4”. Sample was saw cut and wetted to illustrate layers/ color/ and grain. Sample was flipped upside down to capture color variations. The orange/gold color on top is actually the bottom of the sample.
A wild clay sample can tell you a lot just by looking at it. Obviously this is a sedimentary clay because it has three distinct layers and colors. The bottom layer is thin, and is noted by the cleavage crack at the bottom left corner. The top layer is granular and light orange/gold in color, which denotes the presence of iron disulfide (iron). This sample of iron disulfide is light in color, which means total iron content is in the 3-4% range. As the percentage of iron goes up; the color will become deeper and deeper. Naturally occurring magnetite (iron) usually presents medium to dark gray in clay color. Naturally occurring hematite will present light to medium “reddish” in color, with no goldish hue. Iron disulfide typically has a gold cast because the iron is oxidizing (rust), whereas hematite is not subject to this natural process.
The middle layer is dark brown ball clay which typically indicates the presence of inorganic sulfides from lignite coal particles. Lighter brown color means less inorganic material, and darker brown means more. The exception to that rule is organic particles (humus). If your sample was taken from a heavily vegetated area; then the level of organic (humus) will be higher, which like wise will create a dark brown appearance. How can you tell if its organic or inorganic? First, the collection site: open fields or valleys will have less organic material, and heavily vegetated areas will have more. Secondly, a very simple test: take a small 1/4 cup powdered clay sample and add a a bit of water at a time until it forms a pliable ball. Does not have to be all nice and neat; just pliable. If it is sticky or gummy feeling; organics. If you can roll it between your hands without it sticking or smearing; it is inorganic. Yes, there are exceptions were a sample can have both inorganic and organic materials.
Besides the obvious large particles of shale; did you notice the smaller nodules? There seems to be a heavy population of them in this sample; which means the middle layer has a higher percentage of 20-60 mesh particles. Bad thing? No, it can be used for non-functional, large format pieces. If you are going to make cups and bowls, then these larger particles have to come out. Wet processing will allow the large particles to settle out quickly, or dry processing will require a 60-80 mesh screen. This sample was found in an open eroded ditch in a field, so the color is most likely from inorganic sulfide. The presence of these sulfides also indicates a coal seam is nearby: which I happen to know is correct because of the numerous coal mines located locally back in the late 1800’s. This knowledge also helps determine the plasticity of ball clay located next to coal seams; typically they are more plastic. 
The bottom (thin layer) is free from large particles, and because this is a sedimentary sample; also means it is finer and more plastic. As with all clay sediments; larger particles drop out first, and smaller particles drop out last. Remember, this sample was photographed upside down to capture color variance. So the thin layer on the bottom, is actually the top of the sample. Can you field test plasticity? yes. Make a 1/4 cup of the middle layer, and a 1/4 cup of the bottom layer to start. If you have a scale, you can accurately measure what you add to each sample to create a pliable ball. If no scale; add 1 teaspoon, add a second, and once it begins to form a ball, then add 1/2 teaspoon until it becomes a pliable ball that does not crumble, nor overly wet and sticky. Low plasticity clay requires less water to form a pliable ball, and a high plasticity clay requires more water for the same. Exact? no- but will give you some general sense and direction.
Tom
 

Thanks for posting this Mark. I'm a big fan of all things art related and the California scene. In the 70's/80's the work of Ken Price was getting lots of attention and it drew my attention to what was going on.  
Also in the 70's, when I was in high school, my mom worked with a gal who had lived next door to Gertrude and Otto Natzler.  (And helped them in their studio.) When she found out I was a potter-in-training she gave me all her tools and showed me her collection of their work.  Only afterwards did I do some research and found out just what amazing glazes they created.

You didn’t even get to cone 022. Yes, I would rebisque after you sort out your ventilation issues. 
Although, just because I deal with Celsius numbers a lot more, that 1045 number is suspicious to me. 1045 C is close to a cone 04 bisque. Double check which scale your kiln is set to before you do anything. 

that previous life went by at 100 miles and hour, you were too busy to notice all the things you do now as separate from the old daily rat race.   now you have a few more minutes to notice that you still have to work.  the new work is called "chores" and are with us forever.
we all need time to look around at how beautiful life can be if we just sit down and breathe once in a while.