neilestrick

Chances are the underglaze is too thick.
- What color underglaze is it happening to?
- When are you applying the underglaze? Leather hard, bone dry, bisque?
- How many coats, and are you thinning out the underglaze before applying?
- How are you applying the glaze?

The plaster itself should dry the surface of the clay enough that it will release. If it's not releasing quickly enough, then dust some corn starch on the mold or the clay before pressing it. I would not use any sort of liquid on the plaster, as it will just soak in and ruin the porosity of the plaster.

Chances are the underglaze is too thick.
- What color underglaze is it happening to?
- When are you applying the underglaze? Leather hard, bone dry, bisque?
- How many coats, and are you thinning out the underglaze before applying?
- How are you applying the glaze?

A marker will just gum up with the clay, so something that brushes on would work best, like food coloring or india ink.

A marker will just gum up with the clay, so something that brushes on would work best, like food coloring or india ink.

kelsey, congratulations on getting your first kiln.   it is the same kind i started with in 1972 or 3.   it was a good learning experience and i remember the electrician who installed it did not know anything about kilns.   we called in an expert and i was a glad to have him.  my house was built in 1940 and did not have enough amps for anything modern.  forget the stuff we use today!
if the person you are using is not experienced in kiln work and does not even know that other kinds of "fat" cords are not correct for a kiln, ask your local supplier for some names .    if you are lucky enough to have a local supplier.
it really matters that someone knows how to do it correctly.    you do not want to provide the first negative experience that makes him/her learn what not to do.
north carolina is full of potters.   look up someone and ask for a reference.  just throw a rock in any direction and it will probably hit a potter.

A marker will just gum up with the clay, so something that brushes on would work best, like food coloring or india ink.

The plaster itself should dry the surface of the clay enough that it will release. If it's not releasing quickly enough, then dust some corn starch on the mold or the clay before pressing it. I would not use any sort of liquid on the plaster, as it will just soak in and ruin the porosity of the plaster.

You have several things running in different directions here, so it can be confusing. This kiln needs a 4-wire circuit. Easy enough, Sparkie checks the old circuit and maybe it is an old 4-wire job. Maybe it is also sufficient gauge to support 35 or 40 amps as required by the 125% rule. Maybe there is already a 40 amp breaker on it. If so, the circuit is good to go for this kiln. Your remaining problem is the cord on the kiln needs to be replaced. Unlike extension cords and household appliance cords, kiln power cords are made with high temperature type SEO cable to accommodate the heat buildup of long-duration full amperage current when the kiln is running on high for several hours to finish the firing. The stove cord you linked to is not quite up to that spec, but since it is rated for twice the amperage your kiln will pull, it probably will do ok.
On the other hand, if the existing circuit in the wall is not sufficient, Sparkie has some work to do, and there are some choices to be made. The replacement circuit only needs a 40 amp breaker and 8 ga. 4-wire cable for this kiln. But you said you might step up to a bigger kiln in the future, so future-proof the circuit now. The biggest plug-in kilns (which are actually quite common among hobby potters) draw 48 amps and require a 60 amp breaker with 6 ga. wire (though possibly 4 ga. if the run back to the panel is really long). So, ask Sparkie to install the 6 ga. cable and put a 40 amp breaker in the panel. The cable will be a bit more expensive and seemingly overkill for now, but you will only be paying for the labor once. When you upgrade in the future, all that will be needed is a new breaker and receptacle, the expensive part of pulling the cable will already be done.

So you've got a cone 10 ceramic rod, and over the rod is a series of 17 gauge loops that hold the ornaments? So the ceramic rod is what you're worried about sagging correct? The wires will probably be fine. The only answer we can give regarding the rod is 'maybe'. It all depends on how thick the rod is, how long the span is, how much weight it's carrying, etc. There's no way to know until you try it.  Worst can scenario, the rod bends so much that it falls off its supports and you end up with a pile of stuff on the kiln shelf. Best case it works great. 

So you've got a cone 10 ceramic rod, and over the rod is a series of 17 gauge loops that hold the ornaments? So the ceramic rod is what you're worried about sagging correct? The wires will probably be fine. The only answer we can give regarding the rod is 'maybe'. It all depends on how thick the rod is, how long the span is, how much weight it's carrying, etc. There's no way to know until you try it.  Worst can scenario, the rod bends so much that it falls off its supports and you end up with a pile of stuff on the kiln shelf. Best case it works great. 

I don't think that 'work' in itself is the issue. Rather, it's the type of work. Some people can work for hours and hours with spreadsheets on a computer and have no problem with it. Some folks install shingles all day or frame houses. Some teach kids. I can work hard all day in the studio but I would hate other jobs. It's a matter of finding the work that you enjoy, and if you're not totally into clay then it's not going to be work you want to do all day.

Terrible inspector, overloading the breaker and ignoring the manufacturer's instructions. Plus sometimes 48 amp kilns will trip a 50 amp breaker, especially if your voltage is running a little high, which is not at all uncommon. Pass inspection, swap the breaker, and fire it up!

Did you use the term 'ceramic kiln'? Did you explain what it is? That term may not mean anything to them. I'm betting that if you said 'pottery kiln' they would get it, because most people have had some sort of experience with pottery during their childhood or college years. You might just have to explain it to them, and maybe give them some links to the kiln manufacturer's website. Which insurance company? The town will want to inspect it, and if they don't know anything about it they will generally defer to the manufacturer's recommendations for installation.

There are a couple different types of silica board- high density and low density. I've used the low density stuff, and it is incredibly soft and not durable. I have not used the high density, but I imagine for it to be as durable as IFB it would not be much better of an insulator.

If the pieces are very small then they probably won't be an issue. Larger pieces can cause pop-outs after the piece is fired, even weeks after the firing. If you're concerned about your plaster bat, then I'd remake it or simply put a sheet over it before putting the clay on it. A good bat shouldn't have any bits coming off. Make sure you use the proper ratio of water to plaster when making it so it sets properly. If using #1 pottery plaster (recommended), use 7 parts water to 10 parts plaster by weight.

Did you use the term 'ceramic kiln'? Did you explain what it is? That term may not mean anything to them. I'm betting that if you said 'pottery kiln' they would get it, because most people have had some sort of experience with pottery during their childhood or college years. You might just have to explain it to them, and maybe give them some links to the kiln manufacturer's website. Which insurance company? The town will want to inspect it, and if they don't know anything about it they will generally defer to the manufacturer's recommendations for installation.

Make sure you install wires that are suitable for 60 amp.  
If you want to argue with the inspector, and assuming you are in the US, here is the applicable section from the National Electrical code.

210.19(A)(1) General. Branch-circuit conductors shall have an ampacity not less than the maximum load to be served. Conductors shall be sized to carry not less than the larger of 210.19(A)(1)(a) or (b).
(a) Where a branch circuit supplies continuous loads or any combination of continuous and noncontinuous loads, the minimum branch-circuit conductor size shall have an allowable ampacity not less than the noncontinuous load plus 25 percent of the continuous load.

A manual kiln will teach you everything you need to know about firing a kiln, because YOU are totally responsible for everything that happens - what switches to turn on, when to turn them on, when to turn them up to the next level, how to load it so the witness cones are visible so you can turn it off at the right time, yada yada yada. There are lots of potters who have only manual kilns by choice. At the same time, there are lots of potters with modern digital controller on their new kilns who think that having pushed a particular button means that is what happened, and are shocked to learn that didn't actually happen. So, work with this one.
As for the wiring, as Neil and I have noted, this one will require an older form of 240V power with 4 wires vs the usual 3 in most current 240V situations. The required amperage of the circuit is fairly narrow for any kiln. If you get a newer kiln, you will probably get one that is bigger, which will need higher amperage. The trick for this is have the electrician install wire suitable for 60 amps, but set a smaller circuit breaker appropriate for this kiln plus an outlet appropriate for the power cord you get. Then when you get the newer bigger kiln, all you have to do is swap in a bigger circuit breaker and change the outlet. The newer kiln won't need the 4th wire (the neutral), so just cap it off in the box. It's ok to run less power on bigger wires, but not ok to run more power on smaller wires. So, pay the sparkie to do it once with the big wires.

Your best bet is to talk to a refractories supplier. They'll be able to recommend the best product for your application. There are a lot of different types of insulating fiberboard out there. Regardless of the type, though, how do you plan to mount the elements to the inside walls of the kiln? IFB will probably be the cheapest, easiest and most durable way to build it, and it's clearly insulated well enough if you get to cone 6 in 3 hours. Why change the design?
14 amps x 120 volts = 1680 watts. 

The vertical cracks in the bricks don't matter at all. They won't affect the structural integrity of the kiln, because they can't move sideways and fall apart. If that's the bottom row where you've put the wafers, just pin the element to the floor and forget the wafers because they'll probably just crack. They're not thick enough to pin through.

If the resistance of the elements is still within 10% of new then they're still usable. Get a kiln stand or set up some cinder blocks, oriented so the kiln sits on the flat sides and air can flow through below. If the floor underneath is not smooth and level it can be difficult to get the blocks to sit evenly. Do not put the kiln directly on the cement floor. Double check your serial plate, but as Dick said, those kilns need a 4 wire hookup rather than the typical 3 wire system. You'll need 2 hots, 1 neutral, 1 ground. The kiln pulls 26 amps and code requires a breaker that it 25% greater than the draw but no more than 50% greater, so either a 35 or 40 amp breaker is required, with the appropriate size wires, at least 8 gauge. The power cord and outlet should be a NEMA 14-50 (50 amp) because they don't make a 40 amp outlet. Most kiln manufacturers will carry the cord, or you can build your own with SEOW cable if you're familiar with doing that.

Like Bill said, you can't just put the T/B elements in the centers. Yes, it would give more power, but it wouldn't be balanced anymore, and the middle would run too hot. You could, in theory, replace all the elements to compensate for the low voltage, but they would all have to be increased appropriately to maintain that balance, and the whole system may have to be modified to deal with the increased amperage draw. Fix the voltage issue and everything else will work as it should.

No real changes to the unity formula, just revised to use the materials I keep in my studio. Calcined part of the kaolin to avoid issues with it being so high. I'll try to post a photo tomorrow.

If you only use one for glaze, assuming you're glazing hotter than you bisque, you're going to wear out that kiln a lot faster than the bisque kiln. The glaze kiln will need a lot more maintenance than the bisque kiln, and need replacing a lot sooner. The bisque kiln will corrode faster due to moisture from the clay, but it'll still outlive the glaze kiln. A downdraft vent will help to reduce corrosion a lot. If you use both kilns for glaze and bisque, they'll age at the same rate. It's nice on the budget to only have to replace one kiln at a time, but it's also nice to have them on the same maintenance schedule, so really it's up to you.