Are these kilns worth repairing?

[MollyinMN]

Hello,

I'm an art teacher at a small school, and have been offered two Skutt KM-1227 Kilns that haven't been firing properly for free if I can haul them away. The school I'm at used to have a kiln in the boiler room, which suffered water damage after a flood. I mostly took wood fire ceramics in college, and don't know too much about electric kilns.

The contact person is the school grounds keeper, who didn't know too much about what's been malfunctioning. He said they replaced the elements recently in one, and did something to repair one of the displays. One has been turning off at high temperatures, and both have been heating unevenly, cracking pots. They may be 15 years old, he's not sure. There's some chipping in the side walls, and some cracking in the floor. I tried uploading photos, but they were too large, so I have them posted here.  

Does anyone know what might be involved in fixing one of these, and if they're worth accepting?

Thanks!

[liambesaw]

They look good but they also require 3-phase power, which probably isn't available to you at home.  If you don't know much about electric kiln you will need to do a lot of reading and research to repair them, or call a service person.

[MollyinMN]

6 minutes ago, liambesaw said:

They look good but they also require 3-phase power, which probably isn't available to you at home.  If you don't know much about electric kiln you will need to do a lot of reading and research to repair them, or call a service person.

Thanks for the response! I would be installing whichever works better at school -- I'll see if our building manager knows if the building can support 3-phase power, 

[liambesaw]

It's 3-phase 240v, commercial buildings are usually 1 or 3-phase 208v, so it's kind of a weird mix.  If you're getting them from a school and installing them in a different School it may be the same, just be sure to check first

[oldlady]

molly, congratulations on getting this gift.   i would check with Skutt, call them on the phone to talk   TALK  to a technical person on their staff.    ask about the 3 phase question,   read off the serial number and model number to get the age of the kilns and ask any other questions you might have.    of course, that call will be made after someone with the right info in your school building maintenance department answers the question of what power and phase is available in your school.

the age of a kiln has very little to do with its ability to fire the things you want to do.   a kiln is basically a brick box with wires inside that get hot enough to fire pottery to maturity.   it is the type of clay you use that will dictate the cone you will need to reach.   many schools only use earthenware which makes the firing range about 06.   notice the zero.  never confuse 06 with 6.   always look it up in a reliable text.  your kiln can reach cone 8, much more than you would need for cone 06 clay.

kilns that have a history of only firing to cone 06 can last a very long time without replacing elements, you are fortunate that the elements have recently been replaced, they should last many, many firings so you can enjoy your generous gift for years.

[Stephen]

Why not install both of them? Great find, that is 6-7 thousand bucks worth of kilns new and still worth half that. Maybe they didn't replace the thermocouple at the same time. Skutt is a great company and 15 years is really just not that old in kiln years unless they really used it heavily. I think the controller may tell you how many firings.

[Bill Kielb]

These look pretty decent and if you are using them at school you almost certainly have three phase power. For free, for a ceramics program it would be hard for me to turn them down if I had nothing.

kilns are pretty simple and are just big boxes to heat things in. Cracking pots and uneven heating are a description of not understanding the clay process more than a function of machine failure.

I would look closely at these, could be a steal of a deal. Maybe have a reputable kiln tech view them and offer an opinion.

[neilestrick]

Take them both, even if you don't need them both. They are in excellent condition. The floor cracks appear to be normal hairline stress cracks. As long as they don't go all the way through they're nothing to worry about. The chipping in the wall bricks is minor, not a problem either. 

If work was blowing up, they were probably firing too quickly or making the work too thick. Blowing up work is usually not the fault of the kiln. Once you get them hooked up you can see for sure.

Things to consider:

They are set up for 240 volt, 3 phase service, so

1. If you need to run it on 208 volts, you'll need to change the elements. Elements run about $55 each, there are 6 in the kiln. Expect to pay someone about 2 hours labor to change them.

2. If you need to run it on single phase service, you'll need to change out the power cord, and the terminal strip where the power cord connects inside the kiln. You'll also need a new wiring harness for distributing the power from the cord to the relays. All of that will run about $150 in parts, and take an hour labor to install. If your electrician hard wires the kiln, you won't need to change out the power cord since he/she will install wires to make the connection.

3. You may need to change both the voltage and the phase. Even if you do, these kilns are still a great find, $700 worth of changes for what is basically a new kiln. Even if you have to put in a new controller (which I doubt you will), those are only $300, and you're getting like-new kiln for $1000 in parts and labor.

4. If you end up running it on single phase service, on 240 volts the kiln will only get to cone 8. On 208 volts, it will only get to cone 5. A cone 8 kiln can be used for cone 6 work, but your elements won't last as long as a cone 10 kiln. Not a deal breaker IMO. A cone 5 kiln should only be used for work below cone 3.

5. I always tell my customers that there's no such thing as a free kiln. In addition to the potential parts to make to work for your wiring situation, you're going to have the cost of having the electrical service installed, and some sort of venting system. If you are putting it in a smaller room, or a room where people will be, or a room with fire sprinklers, I would go with an overhead hood that will vent fumes and heat. If it's going in another boiler room or some where that the heat won't matter, then you can use a downdraft vent.

But take them both, don't let them thrown them out! If you have more questions as you move forward, let us know.

[Stephen]

Maybe sell one to offset the cost of setting up the other one. 

[Arnold Howard]

The kilns are in great shape.

Eventually kilns will be sold as 1-to-3 phase, meaning you will be able to convert a single phase to 3 phase, and vice versa, easily and with simple tools.

Arnold Howard