Today on the way back from teaching, I stopped by the seaside shell pile to collect some cockle shells for firing. Though I usually don’t find “the good ones”, today I got lucky. Pictured below are the two types in the area. The thin type with the many, shallow grooves comprises about 99% of what one can find, so I usually use those, but today I found quite a few of the deeply grooved bumpy, thick shells. These are better for standing pots on because they are thicker and don’t collapse in the firing, so they don’t need to be stuffed with fire clay, at least for small to medium sized items. They also leave a more interesting mark on the pot.
People sometimes lament the limited effects possible in gas and electric kilns compared to wood kilns, but there are ways to get many interesting effects in gas and electric if you use your imagination and do some experimentation.
This time around I loaded about half of the kiln with saggared ware. 4 incense burners, 3 sake cup refires, 2 boxes, 2 teabowls, and 1 frog toilet (in porcelain, no less).
The incense burners came out most interesting, with a lot of deformation occurring in the clay, which was the goal. Nakayama kun wanted some burner bodies that were deformed and all around ‘grungy’ to fit with silver lids. They were wrapped in rice straw rope that had been soaked in a saturated solution of soda ash, mixed with some feldspar, the idea being to get some focused area effects on the pot surfaces. The soda ate into the clay in places and fluxed the feldspar nicely. One of the burners completely collapsed and stuck to the saggar and the adjacent burner, but I’ll be able to keep 2 out of the 3.
Two of the teabowls, with iron based glazes turned out nicely, but one (the black one) stuck to the saggar and will need some repair on the lip. Nakayama kun is going to do a silver repair on the lip, and I’ll post a picture when it is done. The other, and iron saturate glazed bowl, turned out nicely but I really can’t decide if I like the glaze color or not. Need to whip up some tea in it to see if it shows off the tea color well or not.
The porcelain ring boxes were a complete failure, with cooling fractures I think. I drizzled in a soda/spar slurry on the insides and it was waaay too thick. I think its expansion and/or contraction fractured the pots.
I get periodic requests for Korean/Karatsu style low momentum kickwheel plans, so I thought I’d throw this out there again.
The pictures below are a mix of my kickwheel and the one I based it on, both are based on the traditional pin and receiver type, rather than the modern wheels which use bearings. Having had the chance to use both, I am of the personal opinion that the pin and receiver version responds to a lighter touch and is more suitable for thin and/or small diameter coil and paddle work.
These are not plans per se, but drawings of the various parts with some pictures thrown in. Hopefully, altogether they will give one a good idea of how to put one of these things together. I will be putting another one together in the near future, and will post again at that time. You will notice I do not put measurements in the drawing. This is because based on the wheel size, most or all of the parts could be smaller or larger, depending. It is mostly just common sense. To give a sense of scale, my kickwheel shaft is 40mm diameter.
The biggest thing to influence your wheel size/height is you body and throwing position. There is no hard fast rule about how big the wheel should be. I screwed up when I made my wheel and the wheel head is taller than I had anticipated, requiring me to make a special seat to elevate my tuckus. Make sure you sus out how high you want your kicking/treading foot and how that compared with the height of the wheel head, then figure out how long this will make your stretchers, don’t forget to take into account the thickness of both wheels minus the distance the stretchers will be recessed into them. Also, how much height the tapered sleeve adds between the fly wheel and the bottom steel plate.
Having a drill press to drill the holes for the stretchers is a big help to make sure the holes are straight. I used a little drill stand that was pretty iffy. If you or a friend is good with chisels or has a mortising machine, you can use rectangular stretchers.
I used a lathe to round the wheels. I imagine this is not really necessary. With a good saw and some elbow grease you could start with a square and start cutting off the corners 4,8,16,32…. just stop when you feel the wheel is round enough not to tear up your thighs and knuckles.
It is a fairly simple tool to build if you have a good blacksmith nearby. Oh, the pin and pin receiver were traditionally made from porcelain. That might be a fun alternative to metal…That’s about all I can think of for now. I may post addenda to this if I can think of anything.
The kiln is finished. Yep, you heard right. Done. I can hardly believe it myself.
Cleaning up the front area and getting the concrete in was the last job, and it is done. Now, working on the kiln will consist of playing with the flue dimensions and firing it, something I am looking forward to, and have started getting work ready for the upcoming October firing.
I pulled the forms off this morning and cleaned up the concrete. The sump form had collapsed under the weight of the concrete, so I didn’t get the nice oval I was aiming for, and I had to go in with a hammer drill and concrete bit to clean out some of the concrete that had encroached into the sump area. It was still not quite cured, so not too difficult to break up.
Though I imagine water will still rise in the mouth of the kiln, it won’t be dirty runoff, and the walls of the stoking area will not be eroding every time we get rain. Once I get my hands on an automatic sump pump, I’ll be able to cover the sump and forget about it. Yay!
Actually, looking at the front area again, if we could think of a way to create a waterproof wall across the front of the kiln, we could have the first kiln heated jacuzzi. In fact, we could probably ‘soak and stoke’, relaxing in the hot tub while simultaneously firing the kiln to cone 13.
The concrete truck delivered 1.6 yards of concrete today, and it was a happy thing. I think this will finally solve most of the flooding problem when the heavy rains come, though the water will still probably come up from underneath. So, the sump was left in, and an automated pump will be installed. Best of all, no more muddy mess when firing the kiln!
The truck came at 8:30 and we finished up just before 11:00. The forms held up well with just one shifting a bit. The biggest problem was the sump form which started to crumple from the weight. It all turned out ok in the end, though. Just out of paranoia, I put a layer of ceramic fiber between the slab and the front wall of the kiln to insulate the slab. Also, there is a tube installed so the pump hose and plug will be out of sight for the most part.
There was some crete left over, so I was able to put in a bit of a walkway/work area out the door of the studio. This previously had a step down, which made it very difficult to roll heavy objects like my lathe stand, etc… in and out of the door. Now the step has been eliminated, and a small work area created between the kiln and the studio.
How do you know your kiln is a luxury model? When you built it/had it built, did you really think of everything? How do you know that you have THE KILN that shows everyone you are a winner? a behemoth in the clay world? a demigod of ceramic art? Why, cup-holders, of course.