Notes on terra sig - part 3

So where am I headed from here?
Being on injured reserve these days, I have plenty of time to think.

What my experiments have shown me is that I definitely want to explore this direction further, maybe take it somewhere no one else has. I've already had some happy accidents with streaking, I'm wondering what else is waiting out there.

For starters, I want to go ahead now and get some proper equipment and materials and see if I can make an even better terra sig using Vince Pitelka's instructions.

I've been using sig on my saggar pieces, and I really like them that way. I'd also like to try it on raked raku, although I've heard mixed results of getting the resist slip to adhere properly to a smoothly burnished pot.

The high shine of low-fired sig is lost when the pot is fired up to stoneware temps, but I want to experiment with that anyway. The more satin finish might be just what I'm looking for.

Notes on terra sig - part 2

In part 1, I talked a little about proportions of clay and water and basic clay prep.

Deflocculants will definitely improve your results over mixing only clay and water. What they do is help separate all the individual clay particles and keep the smaller particles of clay suspended until the larger particles settle out. What to use is a whole other matter.

By far, the most recommended deflocculant for terra sig is sodium silicate. It's very effective, and only a few drops are needed. Other choices include soda ash and tri-sodium phosphate (TSP).
For my first experiments, I used TSP since it was readily available at the local building store as a cleaning agent. Make sure you get actual TSP, and not TSP substitute. I used about a teaspoonful in a gallon or so of slip and it was plenty. Later I used about a tablespoonful in a 3 gallon batch of red sig slip.

So then you mix well - I used a paint mixer attachment on an electric drill for a few minutes.
Depending on the clay you'll usually see an almost oily appearance to the surface when you stop stirring from the fine clay on top of the water.

Then walk away. Let it sit. 24 hours minimum. My first try didn't sem to be separating into distinct layers, so I let it sit for 3 days.

You'll either get layers or not, but either way you'll then want to carefuly siphon off either the top 2 layers, leaving the heavy third layer behind, or siphon off the top 1/2 to 2/3 of the liquid if there isn't distinct layering. This is the terra sig you've been after.

You'll need to experiment with the consistancy. As I said earlier, my first batch used WAY too much water, so I had to evaporate some of the water away to get a usable product. I actually poured it into an old bisque bowl I had laying around which let it evaporate and also absorbed and wicked away water through the bowl.

Next time - Future testing

Notes on terra sig - part 1

I've been looking at all my various notes on all the variations of terra sig. I thought I could put it all together and maybe make sense of it all.

Up to this point, I've just been trying to see what kind of results I could get without a whole lot of trouble, gram scales, deflocculants, and measuring specific gravities. I think I did pretty well, I even surprised myself a bit on my first tries I suppose. But comparing notes, and sitting down and doing a bit of calculation and comparison, I probably could have done a bit better.

This first time, I used about 2 pounds of dry clay to a gallon of water. From what I'm looking at, that's probably way too much water to start. It made the slip easier to mix, but was probably overkill and all that water has to be evaporated back off. The trend I'm seeing is something more like a little less than 1 cup water for every 100 g dry clay. What I used was 16 cups to 1000 g, it should have been about 10 c.

And do yourself a favor, use dry clay, it will mix a lot easier. I busted up some scrap throwing clay in a heavy bag with a big hammer. Don't do it in the open, because 1) you REALLY don't want to breath that fine dust, and 2) that fine dust is actually what you're after, so don't waste it.
If your clay is still moist, just use a sur-form tool or cheese grater and shred it into a bucket and let it dry. Then add it slowly, a little at a time, to the water, then let it sit for 20-30 minutes or so. then use the power tool of your choice to give it a good mix. I used a paint mixer attachment on a drill.

Next time - Deflocculants, settling, and siphoning.

Getting back on track

It's been a week tomorrow since the big wreck, and I've been at a bit of a loss as to what to post. It's pretty clear that I won't be back in the studio any time soon. One of the more painful injuries is a very bruised, very sore sternum. I don't even like to think about trying to wedge or center clay.

I do have some pieces from my failed attempt to re-familiarize myself with the old #112 claybody that are coming through the bisque firings at the center, so I'll be able to glaze them soon. I did take the remainder and wedged it up on the tables and sprayed it down. Hopefully it got a good dose of microbes to help it age. It should be good and ready by the time I'm ready for it again.

I never got a chance to say anything in all last weeks excitement, but I'd thrown in the towel, raised the white flag and went back to my old familiar white stoneware. I'd been trying and trying to get the 112 to work for me, and was just being frustrated. My clay time is precious to me, and I just decided I didn't want to spend my fun time being frustrated and pissed. I threw a 12" vase on the first try.

I'm also spending some time going through old notes I've collected, ideas, sketches, etc. (when I'm not sleeping... I'm doing a LOT of sleeping). Maybe I can get them more organized and possibly share some. And there's been some interest in more details of the naked raku and aluminum foil saggar techniques, so I hope to post more stuff about all that too.

The blog has been up for a little over a month now and I'm having a lot of fun with it. I'm enjoying the community, and have made new acquaintances from around the world.

Very sad news from Scotland

I just got some horrible news from my friend Nicola at Argyll Pottery.
http://www.argyllpottery.co.uk/
She tells me that Alan was in an accident riding his motorbike on Monday and was killed. I don't have any more of the details.
There's a little more info at Hannah McAndrew's blog.

She wanted our assistance in spreading the news and letting people know. I know most of you have a lot more traffic and bigger blogrolls than I do.

Please keep his family and friends in your thoughts and prayers.

Crunch time

So Friday after work I came home and went back out to get gas for the lawnmower to do some yard work this weekend.

I'd usually have just went Saturday morning, but the gas stations all over the area were raising their prices to outrageous levels in a panic over what hurricane Ike might do to Houston.

But I went Friday night.

And I normally would have turned right to go to the closer independent gas station that's usually cheaper than the one by the highway exit. But I'd just driven past that station and it had the highest price of ANY of the 8-10 places I drive past on the way home.

So I turned left.

Halfway there, a Ford pickup truck (F150 or bigger) in the oncoming lane swerved directly into my lane. Accounts vary as to whether he was swerving to avoid rear-ending someone in front of him, or simply passing in a no passing zone. Regardless, all witnesses put him clearly in the wrong. I swerved to the right to the side of the road/ditch, as they teach you way back in driver's education, but so did he, and we hit head-on.



Looking at all the carnage, it's amazing, but I'm mostly ok. After a trip to the hospital on the body board, cognative tests, blood tests, and a CT scan I 'walked away' from this.

I feel like I went 16 rounds with Mike Tyson, but no broken bones, no internal organ injuries. Just some major bruising and muscle aches that I'm sure I'm just beginning to experience. Actually found a big one last night on my left hip from the seat belt, to go with the big one on my left shoulder.

Moral of the story: Seat belts and airbags save lives. Plain and simple. Being a nice day, my driver's window was down. The seatbelt kept me IN the car, and the airbags saved my life. The first responders were amazed I was in as good of shape as I was. These people deal with this every day, and it really shows on their faces when they can take someone out alive from something like this.

Couldn't help putting this one in.... When my wife went to clean out the car, she found a bisque pot that I had in the trunk. Intact.


Those Toyota engineers really know what they're doing.

Clay Review -Standard #112

Today's clay review is Standard Clay Co. #112

It's a buff cone 6 stoneware with dark specks of manganese. The same clay is available without specks as #225.

Lots of people like this clay. It's generally the recommended clay for all the beginning wheel classes here at Pullen. I used it myself exclusively for several years, before branching out and experimenting with other clays.

I'm still struggling to re-adjust to it after using the smooth white stoneware for my saggar work. I'm better able to control it when throwing small work, 1, 1.5 pounds, but run into serious issues over 2-3 pounds. At this point I think I'm going to take the advise of Deborah and Gary and age the rest. Just divide it, wedge it a bit, and take it home for a while.

The iron and manganese react well with glazes giving nice results. As usual, the grog, grit and manganese make for a poor surface for burnishing. As the clay shrinks in firing, it all pushes through the surface. It's still an interesting surface though, just not completely smooth.

Saggar Firing - Lessons Learned

After going over the test results of the experimental pieces I did at the last saggar fire, I learned a few things. Some are probably obvious to those more experienced than I.

For any color at all besides black, some kind of metal salts/oxides are required. I probably should have realized this, but I was hoping perhaps some of the trace minerals in certain organics would be strong enough on their own, trapped under the aluminum foil. They weren't. Their main function seems to be to influence the colors/shades of any major metals already present. Ferric chloride, copper carbonate, and copper sulfate are all good starting points.

Pieces of broken off pinecones give a nice dark black. If you want good blacks, pinecones and needles are a good bet. It also doesn't take much, start conservative.

Brushing on ferric chloride works just as well as spraying. And it's a LOT safer, in my opinion. Airborne ferric chloride is just bad news. You still want to wear plastic gloves and be very careful. It'll also ruin your brush, so use a cheap one, foam works well. I want to experiment with building up varied layers of diluted FeCl in the future.

Tinfoil saggars are the way to go, in my opinion. Comparing with other work from clay saggars, and pit firings where some was wrapped in foil the same way and some not, the colors just seem to come out more intense. You can also achieve good results with much less raw material since you don't have to fill the space between the saggar and the pot. That's just my personal taste. Some people like more delicate, muted coloration and that's cool too. And despite reading in several places warning about not firing past the melting point of aluminum (1100F), I've never seen or heard of a problem with it. The aluminum foil doesn't melt, it simply burns away. I think the regular weight stuff works fine, but experiment with some heavy duty and see what you like.

Terra Sig takes the color just as well as burnished or unburnished clay. I thought that maybe since it is a tightly packed surface of smaller platelets it would be less permeable to the smoke and fumes, but it didn't seem to be a problem. Your clay, however can make a big difference. Earthenware bisqued to cone 06 is much less permeable than a mid/high fire stoneware bisqued to cone 06. The colors are still very nice, but are lighter and more delicate. Again, lots of room to experiment.

More detailed instruction is available in Alternative Kilns and Firing Techniques by Watkins and Wandless. It's chock full of ideas, many of which can be mixed and matched between the different techniques. This one will really get your imagination flowing.

For more posts about saggar firing, click on the SAGGAR tag below.

Tagged...

So I was tagged last weekend by Judy Shreve.

My dilemma being, every other blogger I know has already been tagged at this point. Whoever started this thing should have more carefully examined the mathematical consequences of each tagger tagging 6 more taggees.... I'm just not comfortable guerrilla tagging bloggers I don't really know.

In the spirit of playing along, here are my 6 random things:

1) I studied classical piano from age 4 - 18. I also played flute and trombone in school band.

2) I was briefly trilingual, after studying French 3 years in high school and German 2 years in college.

3) I am Reiki master, finishing my teacher certification.

4) My other love is landscape/nature photography, growing up the son of a wedding photographer.

5) I took my first, last and only roller coaster ride last year. It was not my idea of fun. Maybe if I had started as a kid...

6) I can hold my own in the kitchen.

Odds and Ends

It was a non-typical week here, since Hanna's impending visit shifted everyone's priorities, especially with her big brother Ike close behind.

I spent time preparing the yard, mowing, bringing things inside, while my wife shopped, cleaned, and organized and restocked the hurricane kits. She did an outstanding job.

Hanna is now passing to the east of us, giving us some much needed rain and some wind. And Ike looks like he's headed for the Gulf. I just really don't know what they're going to do with another major storm down there so soon after Gustav.

Overall, not much time for actual claywork - priorities... It does get me thinking about the whole new level of readiness involved if I had my own studio, at the house or otherwise.

Clay Review -Highwater Little Loafers

Today's clay review is Little Loafers, from Highwater Clays.
Formulated as a cone 6 version of their cone 10 Loafers Glory, it is also a smooth, white stoneware with no grog or grit.

I started using this body last spring, after another potter suggested that if I liked the Standard 563, I'd probably like Little Loafers. They were right! To me, it has all the smooth response of the 563 without as much of the fussiness. It seems to stand up better, and the S cracks have been nearly non-existent. The ones that did appear were clearly my fault, and were on pieces intended as tests and not at all properly thrown.

Like the 563, it takes a beautiful burnish and saggar fires well. I haven't done any handbuilding with it, but from the way it throws, I'd suspect that while it might not be ideal, it's probably better behaved than the 563.

It quickly became my favorite. But alas, there was none on the latest clay shipment.

New Blogger feature: Following

Just added a new gadget over in the sidebar, Google Following. They've been rolling it out gradually and today it finally became available for me.

You can follow a blog either publicly, which creates a link to your own profile, or anonymously, and can stop following at any time as well.

Followed blogs will then appear in a Reading List inside the Blogger Dashboard, as well as adding the subscription to your Google Reader. It seems like they're just tying all these tools together.

It seems like it could be fun. We'll see how it goes.

Clay Review -Standard #563

I thought it might be useful to share my personal thoughts on the various clay bodies I've used and loved or hated.

First up is Standard Ceramic Co. #563. It's a white stoneware, cone 6, no grog.
I really liked this clay from the first time I used it. In the beginning, it was a bit harder to control because it was so much smoother and responsive than what I was used to.
Having no grog, sand or grit, it burnishes very well if you're into that sort of thing. I am.
It can be a bit more prone to S-cracks in the bottoms if you leave your bottoms a bit too thick or don't compress them well, so pay attention to your technique and don't skip steps.

I've not handbuilt with it, but others have said it doesn't have enough grog (none) and is difficult to work with. Your mileage may vary.

Clay challenge pt.2

Deborah Woods had a good idea regarding my recent clay challenges, thinking it could be the clay hadn't aged sufficiently yet.
I hadn't considered the aging factor. But now that I think of it, it could be contributing to the problem. The clay I got was 'fresh off the truck', so it hasn't really aged. However, so is the white stoneware I've been using, as well as all the other clay available at the center, so there's some sort of baseline usability there that the buff clay doesn't seem to have.

The instructor that used that clay also had multiple bags in various states of age, with trimmings and reclaim constantly being wedged in, so that probably improved things a lot. And as I mentioned, he throws very dry. The first thing I think I'm going to try is cutting way back on the water.

For me, an idea clay would be serviceable 'off the truck' and any improvement with age would be a bonus... That probably isn't very realistic, and it make sense to age your clay, I'm just not in a situation where I can age clay right now.