the secret life of potters

This week:

Obsessing over making an oxidation fired plate coordinate with a reduction fired plate.

Obsessing over making mini butter churns fired in oxidation that correctly replicate the 23" tall salt fired original in both proportion and glaze.  I may be explaining this more at a later date.

Major obsessing about getting this mug commission right. 

Size, color...yes, but mostly fear of glaze failure during the last firing for the decals.  Having had a few problems with pinholing in the past, I did a search and found that better kiln ventilation may solve the problem- leaving the lid and portholes open up to 500 degrees F.  That, and spacing the mugs about 2 inches apart in the kiln.  Success! At least this time.  And, hurry up to get some birds and cairn parts in the kiln to be bisque fired along with the decal firing.  Luckily, the sun was out to help the drying along.

15 emails and several picture taking sessions about a possible commission through etsy. It is possible I gave the customer too many choices.  Some of the test tiles involved:

And, these are a few of the closed forms in the glaze firing this week.  Made these just because I wanted to and am trying to learn what I can do glaze-wise with this spotted clay.  Will have these at River City Farmer's Market tomorrow.

Picture taking session is not over until I can focus on the interactions of a wood ash glaze and several other glazes used on this pot.  Yes, this is what we obsess over.

mystery albany slip

I made some more mugs in this plum glaze I like.  Some are for a customer, the rest will go either to the market or etsy.  There's something very attractive to me about this glaze.  At first glance, you think it's black, but then you notice the warm plum tone it has.  I mentioned this glaze in a former post, plum.  Now I'm trying to decide whether or not to mix it in larger quantities and how I'd like to use it.

 I find it difficult to capture the true color of this glaze with my camera, so here's two of my attempts. 

I found this glaze on a Clayart thread:  

Plum Gloss (cone 6)

Albany Slip     70

Yellow Ochre  10

Frit 3134          20

Isn't it great to only have three ingredients to weigh?  One problem- I no longer have the recipe for the Albany Slip substitute I used in this glaze.  I used to rely heavily on Albany Slip based glazes.  The real Albany Slip, that is.  When it got mined out I turned to making substitutes, trying to find one that would work with my glazes. I also tried a couple of commercially made Albany subs. The only one of my glazes that worked with the substitutes was a gunmetal color.  Eventually I gave up and started testing new glazes to replace the old.  About a year ago I cleaned out some stuff in my work space. One of the things I tossed was some Albany Slip sub recipes.  I figured I'd use up the sub I had left, then rely on commercially prepared ones if I ran across a recipe that calls for it.  Problem is, when I tested a Laguna Albany Slip in this Plum recipe it looks quite a bit different from my mystery mix.  

 These test tiles are (1)Licorice Black,  (2)Plum with my mystery Albany sub, and (3)Plum with Laguna's Albany sub.  It's very difficult to distinguish the first and second test tiles in this picture. Laguna's is slightly transparent and more glossy. These tiles all have a brush stroke of white slip going across the middle.  You can see that white slip through the Laguna tile.  I brushed Rutile Green from Bill Van Gilder over the Plum on the mugs and across one corner of the Licorice.  The Licorice (Ron Roy's) is a nice glossy black.  There's a swipe of white glaze under it- barely visible. I tested it because I wanted a good black glaze.  Another reason for testing it is I may be talking myself out of widely using the plum. When someone picks up a piece glazed with this plum I feel I have to tell them it's not black.  I know if they happen to have black granite counter tops, they might be in for a surprise when they set their new pottery piece down. 

I had this test tile in a previous firing. This is Graces yellow under Plum (top) then swiped across the middle over Plum.  I thought the interaction of the two glazes on the top was interesting.

Since that test looked promising I thought I'd try it with a couple of other Grace's based glazes.  Not the results I hoped for.  Something about Grace's yellow being high in rutile?

hodge podge

I was back to my old tricks with this kiln firing.  Had a lot of different items that required different glaze treatments so I took a long time getting this kiln load ready.   

 I'll pass these on to a jewelry friend down at the farmer's market.  I have no talent in this area.  She'll know what to do with them.  I'm interested to see what she thinks of the bird pendant.

 I almost cannot do a firing without putting in some tests.  On the left is a black slip using a mason stain for color.  Top line is under glaze, bottom over.  I was interested in getting a nice sharp line for drawing black over white.  This does it, but it's really dry.  The other is a glaze (the green) I've used before, but this test tile is a lighter clay than my usual.  Tested it with an Albany slip glaze I've had around for awhile.  I tested this Albany slip glaze a couple years ago but hadn't used it on any pots yet.  It was fine then, other than it was supposed to be tan, but obviously is much darker.  I wanted to see what these two glazes looked like together.  I was envisoning a dark glaze on the outside of a bowl, the light green inside.  You can see how it shivered off. I also used it on the rim and inside of a vase. Upon opening the kiln I saw the rim of the vase had shivered.  That was yesterday. This morning I went to pick it up and saw it was cracked all over.  I suppose it was caused by the tension of the poor fitting Albany slip glaze inside the pot.    

Better. I refired a couple of candleholders that looked a little flat to me.  Brushed on a little rutile and clear glaze here and there.

 Something a little different for the acorn finial.  I like it , but realize this may have been better to come out with a couple of months ago.  Kind of fallish looking.

 I had quite a few tiles in the kiln.  This darker clay can stand alone nicely.  My regular throwing clay has some color, but looks bland next to this clay. I might try getting the hangers on the backs of these tonight.  I still have a table full of bisque ware waiting to be glazed, though. This morning when I went downstairs to the basement where I work I could only stand and stare for a few minutes- so much to do I couldn't decide where to start. 

Still need to work on photographing this flat stuff if I'm ever going to put it on Etsy. 

about those glaze tests-

 More details on those glaze tests from the last post.-  I felt I should do a little checking on a couple of glaze ingredients, epsom salts and borax, I used recently on test tiles.  Mainly, I wondered if one or the other might damage the kiln elements. I found nothing that indicates this could happen.  Someone let me know if it does?

About Borax. O.K. I remember now. Back (way back) when I had just graduated from college I was looking for a way to work in clay. The problem being that I had no money to buy equipment and no space for it. I did a little research (without the internet- Wow!) and found info on handbuilding pots and doing pit and sawdust firings. Glazes were minimal, and included terra sigillata and a kind of slip with borax added. The borax acts as a low-fire flux. I tried these methods and got some interesting results. A lot of nice flashing from the pit firings, especially. I found it difficult to get the clay hot enough to vitrify using these methods, though.
Here's an interesting article showing a spatter-on method with borax. I wonder if I could get salt/soda fired results in my electric kiln doing this.
http://www.ceramics-decor.com/spattering-borax-on-colored-glaze.html
Here's another source for borax:
http://www.washing-machine-wizard.com/what-is-borax.html
This next one answers another question I had- Can I use the stuff off the shelf in the laundry aisle at the grocery store? Apparently, yes. Which is what I took a chance on when I made up the glaze test. I wanted to make sure before I made up a whole bucket load of the stuff, though. Here's a thread about that:
http://www.potters.org/subject111409.htm

The info on epsom salts was new to me.  Hey, why I didn't already know this? Epsom salts is used to keep the glaze in suspension.  Many of my glazes call for bentonite to do this.  This is the first time I've come across using epsom salts.
Check out this link-
http://www.glazefixer.com/postreview.aspx?PostID=50&PostTitle=What%20are%20Epsom%20Salts?
And this explains why my Grace's yellow glaze is rock hard and takes 45 minutes of hacking and stirring to make usable.  Why didn't I know this?!!!
http://www.claytimes.com/articles/glazeadjusting.html

This is where I got the recipe for the Chun glaze.  It was posted on Peter's Pottery.  He suggests adding 10-20% borax to lower the firing temp to cone 6.  I used 10%.  I'm not familiar with what a chun glaze is supposed to look like by itself.  I would say this one is satin, mostly smooth with just a slight orange peel texture. 
http://opopots.blogspot.com/2009/03/chun-glaze.html
He layered the chun over a temmoku glaze.  There was one I've been wanting to try.  This Temmoku Gold is from Frogpond Pottery and it really does have flecks of gold.
http://www.frogpondpottery.com/glazestability/glaze0013.html

A little rehash on the pictures-

 Back row, second from right is the Temmoku Gold.
Front row, middle is Chun.  Second from right in that row is Chun over Temmoku.  Far right is Chun over a brown engobe.

The epsom salts are in the clear glaze- back row, the first 3 test tiles. First is clear, no colorant. The next 2 with colorants, obviously. All the rest are Grace's yellow. I upped the rutile a little and played around with brushing a couple of clears w/Fe over the glaze here and there, which basically had almost 0 effect.  These are cone 6 glazes.

This looks very similar to the Chun over Temmoku combination but is actually Grace's blue over Albany Plum. Used a wick holder as I was out of test tiles. 

getting organized

I was working all last week on a little studio improvement project.  Actually I thought it would take two days, but you know how that goes.  Had help from my advisory committee (husband and son).  My son also did the hammer drilling on the cement blocks.  I'm glad I didn't try to take that part of the job on myself after seeing the dust and debris flying.  Here's how it looks-

    I know this is not exciting to anyone else but this gives me a lot more storage, better height to use scales, and frees up some floor area.  I didn't have a good place for my glaze test tiles before and now I have them up on the pegboard safely out of the way but easy to see.- No more broken tiles!  Underneath the bottom shelf is enough space for my 5 gal. glaze buckets.  What I was using before in this corner was a big 50's linoleum topped table. It was in the house when we bought it.  Kind of neat, but it took up a lot of space without giving me practical storage.  Yesterday I finally got everything put back together so I'm ready to get back to making pots.