neilestrick

I stopped using Gerstley around 2003 when it disappeared before Laguna started production again. I was working as the clay and glaze tech for A.R.T. clay at the time, and spent a great deal of time helping customers try to reformulate with frits. Unfortunately, there were a lot of recipes out there that used a very high percentage of Gerstley in them and couldn't be reformulated. Most of those were not good glazes from a durability standpoint, though, so it's not all bad that they went away. I regularly get batches of glaze materials donated to me or sold to me for cheap from people in the area who are moving away or simply shutting down there studios for whatever reason, so I've got a few bags right now. I've reformulated some of my class glazes that I usually use 3134 or Gillespie in so that I can use up the Gerstley, but I won't miss it at all when it's gone. I prefer Gillespie or frits. FYI, most industrial ceramics companies won't touch Gerstley because of all the issues that it's had over the years. I was talking with a rep from HC Spinks (they supply Kohler with their clays) one day while working at A.R.T., and someone was talking to a customer about Gerstely and the rep was shocked that we used it, especially that we used it in glazes. He said the only people he knew of that used it in any sort of firing process was the roofing tile industry, which has very broad tolerances.

I've used Gillespie Borate for a long time, and it works great. It tends to be a bit stronger than Gerstley, though, so definitely test. I've found about a 3-5% reduction to be necessary in most of my glazes.

What are you looking for, and what discouraged you?

Your kiln is about 0.6 cubic feet in volume. L&L makes a 0.5cf model, so just slightly smaller, with 3" brick, and at 2160 watts they rate it at cone 6. Their cone 10 model is 2,800 watts. That said, I've got a 0.6cf Evenheat with 2.5" walls and a 2.25" lid that I put 2800 watt elements in and it's got plenty of power to spare getting to cone 6. It could hit cone 10 without struggling in the least. It works about 20% less hard than my larger kilns. So I would think that somewhere around 2400-2500 watts you'd be fine getting to cone 6 and have good element life.

An easy place to start is an equal parts body- koalin, fireclay, ball clay, silica, feldspar- which makes a good cone 10 body. From there you can increase the feldspar to get it down to cone 6. One thing to thing about is where you really want to spend your time as a potter- making clay or making pots. Since you have a resource near you (IMCO) that can mix clay bodies quickly and efficiently while still using local materials, you've got the best of both worlds and it seems like you don't really need to mix clay yourself. Most places that make clay will mix custom bodies, so consider using your Soldner mixing for testing and then having IMCO mix larger volumes for you. Clay mixing and pugging is really miserable work that's really hard on the your body and potentially dangerous to your lungs, so the less of it you can do the better.

This is more than enough to be worried about. Are you sure it's kiln wash and not ITC coating? If it is ITC, then you shouldn't have any problems if it was applied properly. If it's kiln wash, I would be worried about how it will affect the elements, and at some point it will start flaking and the kiln will need to be totally scraped down, which is not an easy project to do without damaging the bricks. She can probably flip the lid slab, but if it's cheap crappy kiln wash it could cause the elements to fuse to the bricks. At some point the kiln will probably be more trouble than it's worth.

You said before that it was chalky after firing, too. Did you mean after the bisque or the glaze firing? How does it look after glaze firing? If it's fine after glaze firing I wouldn't worry about how it looks before firing.

What brand and model of clay is it? What cone are you firing to?

It's been several months since this thread was started. When trying to reach someone directly, either @ them or better yet send them a direct message by clicking on their name and then on the message button.

They may fire flat, depending on the type of clay you used, but they may not. The glaze may also come out different, but it may not. At this point you've got nothing to lose, so it's worth a try. In general, unless you're firing to low fire temps, you should always have the pieces sitting flat on a shelf.

It will actually survive the thermal shock better if it is thinner, because it will cool more evenly. The thicker the walls, the greater the difference between the temperature of the inside and outside surfaces. That difference is what causes cracking because they are contracting at different rates. IMO, functional work should never be more than 3/16" thick unless it's very large.

I use a popup, the Pro Expo from Instant Promotion. I've used mine through about 100 shows so far, and in some really, really bad weather. It's super heavy duty, all the connecting brackets are aluminum, and the sides and top are waterproof. The peak is super tight and tall enough that water won't puddle in it. The walls are tall enough that pro panels should work. To really make them sturdy, popup canopies need crossbars to keep the legs from moving and flexing. I built some that I can attach about halfway up, which stiffens up the frame and keeps the wall from flapping into my displays. Instant Promotion does have crossbars, but I haven't used them. They're made so that the sidewalls can attach to them to hold them tight. The only downsides that I have found are: 1. The canopy frame and top are heavy. The whole thing weighs like 70 pounds and it's bulky. 2. The top fits really tightly, so it takes some muscle to get the first leg or two locked into place. 3. The walls fit really tight, too, so it takes some practice to put them on so that the corners all meet up correctly. There's not much room for error. Once you get used to all that you'll find that it's worth it to have something that fits together really well and doesn't flop around in bad weather, unlike most popup canopies. For weights, you want at least 40 pounds on each corner. Some shows require 50 pounds. I use 36" long pieces of 2" square steel bar that weigh 40 pounds, and they work great. I set them on the feet and strap them to the legs. They're super slim and easy to haul. I got a deal on mine, but would expect it to cost about $100 each now. Instant Promotion has some weight options that are pretty good. The fact that the canopy itself is quite heavy really helps, too.

Yes, the controller will start in whichever segment matches the current temp.

Most if not all of your pieces will probably be fine. Some glaze melting will start at bisque temps, but shutting down at those temps usually doesn't cause any problems. Start it back up and fire to cone 5.

There's a good chance it will flatten out. I vote for waster slab as well. Coils will probably cause other warping issues. Put some alumina wax or kiln wash on the slab. The slab does not need to be bisque fired first.

This is a good product, and small pieces like rings can be fired with a torch. And it's fun to work with. There is a shrinkage rate, though, so fitting a ring may take some work. However the product has been around long enough that you can probably find charts that say how big to make it in order to finish with a certain ring size.

These appear to be brick makers, however it may be worth a call to see if they are willing to sell you sone clay. As brick clay it may be very chunky since they probably don't do a lot of refining. Why do you need it to be locally sourced? Is this a geology project, or are you just looking to reduce your carbon footprint? As potters we are at the mercy of industry, because all the potters in North America don't use enough clay to support any clay mining and processing operation. We have to buy our ingredients from whatever sources are available. For companies like Amaco and CSC that make clay bodies, they will source their ingredients from a nearby as possible, but that generally means from this half of the country. A lot of kaolin and balls clays are mined in Georgia and Tennessee, for example. Clay body suppliers on the east coast and in the midwest typically do not use clays that are mined out west unless it's a clay needed for its unique properties, and companies on the west coast will often use a lot of clays that are mined out there. For other clay body ingredients like feldspars we have very few options so they may be sourced from farther away. With glaze materials we have virtually no choice in where the materials come from. If you want truly local clay, you're probably going to have to dig your own.

Yes, ideally the blank ring should be in the middle, assuming it's made with the box connectors. The cone is over-bent, greater than 90 degrees. You should adjust the tab on the weight, moving it just slightly lower so it shuts of earlier. As for reaching temp, I would go 1 cone higher with the Sitter cone, which should get to the shelf cone.

What sort of burner setup is it? Does it have a ring pilot that goes around to all the burners? Baso valve(s)?

Digital kilns have a fuse for the controller, typically a 0.5 amp fuse. It can usually be found on the front or side of the control box. Kilns that pull more than 50 amps are required to have branch fusing, meaning a fuse for each branch of the wiring going to the elements. A manual Blue Diamond kiln probably does not have any fuses.

I wouldn't mess with the one with the big black pits. The others you can grind smooth and then coat them with kiln wash. Any small amount of remaining glaze will absorb the kiln wash and stiffen up, and can then be re-ground and re-coated if needed.

The cone in the Sitter should be bent to 90 degrees. If it's less than that then you need to adjust the Sitter.

Thank you!

All 6-50 power cords can handle 50 amps. Prices vary greatly, so get whatever is affordable for you. As for the ground, your main breaker box should already be grounded, so the ground wire goes from the breaker box to the outlet as one of the 3 wires in the circuit, and from there to the plug and power cord to the kiln body. If your electrical system is hooked up properly, then the kiln will be grounded when you plug it in. Just make sure the ground wire on the power cord is attached to the grounding stud in the kiln control box.

Sanding the area to be painted will also help with adhesion. I think most paints other than epoxy will be quite prone to scratching on a glossy surface.