Can a kiln be rewired or converted to fire to a higher temperature?

[toninz 0]

I've got a small top loading kiln which states that the max firing temperature is 1000 degrees Celsius, however I really need to fire to Cone 6 (1240 ish).  Is there any way a kiln can be converted or refurbished, or rewired in order for it to fire to a higher temperature?

[neilestrick 4,808]

You can put higher powered elements in it. You may be able to get those from the manufacturer, but if not you can get them custom made. The main issue with doing that is that the kiln will pull more amperage. That means you'll have to make sure all the wires, switches, relays, power cord, etc in the kiln (pretty much everything that the electricity runs through) can handle the higher amperage, and if not you'll have to upgrade it. You'll also probably need a new circuit breaker and wiring and maybe a new outlet, too. So it could get expensive really fast. Depending on the kiln and how big a change it is, you may not need to do much of anything else to the kiln besides the elements. Chances are the circuit breaker and wiring will need to be changed, though. If you're not familiar with electricity and kilns, it may be something you don't want to pursue unless the manufacturer has the elements and can tell you what needs to be done.

[Sorcery 210]

Gas!

I don't think researching the electricity is worth your time.

It'll be cheaper to just buy a different kiln.

Or go gas!

Sorce

[toninz 0]

Thank you for the advice.   It is a very small kiln so perhaps re wiring won't cost too much.   I'll look into it ... fingers crossed.

[jrgpots 274]

The lower cone electric kiln walls are thinner than their cone 10 counterparts.  You may want to think about removing the stainless steel and wrap it with kaowool.  When you rewrap the kiln with the stainless steel, don't squish the kaowool. Instead, you may need to buy a 6 -9 inch wide sheet of stainless steel to cover the the gap  in the original stainless steel sheet metal.

Jed

Edited August 10, 2020 by jrgpots

[neilestrick 4,808]

52 minutes ago, jrgpots said:

The lower cone electric kiln walls are thinner than their cone 10 counterparts.  You may want to think about removing the stainless steel and wrap it with kaowool.  When you rewrap the kiln with the stainless steel, don't squish the kaowool. Instead, you may need to buy a 6 -9 inch wide sheet of stainless steel to cover the the gap  in the original stainless steel sheet metal.

Jed

There are lots of 2.5" brick electric kilns out there that go to cone 10. In fact, most kilns that are rated to cone 10 are rated cone 10 for both their 2.5" and 3" versions. The exceptions are a few models where the 208 volt 1 phase models are underpowered, but that's often true for the 240 volt versions, too. While wrapping it with kaowool will definitely help, it's really not necessary if you have the right elements, plus there are a couple of drawbacks. First, it's not easy to work with in that application. Second,  it's dangerous to breathe in the fibers. Third, if you keep the outer jacket loose enough to prevent crushing the fiber, the bricks aren't going to be held tight and you're going to get a ton of movement every time you open and close the lid or lean on the front edge while loading/unloading the kiln. When bricks move, they break. I'd focus more on just getting elements that are powerful enough. work and leave the rest as is.

[jrgpots 274]

Sorry for the misinformation.

[toninz 0]

29 minutes ago, jrgpots said:

Sorry for the misinformation.

No problem at all - it's all part of the learning curve :-)

[toninz 0]

On 8/8/2020 at 2:04 PM, neilestrick said:

You can put higher powered elements in it. You may be able to get those from the manufacturer, but if not you can get them custom made. The main issue with doing that is that the kiln will pull more amperage. That means you'll have to make sure all the wires, switches, relays, power cord, etc in the kiln (pretty much everything that the electricity runs through) can handle the higher amperage, and if not you'll have to upgrade it. You'll also probably need a new circuit breaker and wiring and maybe a new outlet, too. So it could get expensive really fast. Depending on the kiln and how big a change it is, you may not need to do much of anything else to the kiln besides the elements. Chances are the circuit breaker and wiring will need to be changed, though. If you're not familiar with electricity and kilns, it may be something you don't want to pursue unless the manufacturer has the elements and can tell you what needs to be done.

We need someone like you in New Zealand - there's only a couple of people in the whole country that work on kilns and now they're saying they're too busy to do anything else except service and repair kilns that they make and / or import.  I'd love to learn more but I'm sure, like most specialised industries, it takes years and years of practical experience.

[toninz 0]

On 8/9/2020 at 12:38 AM, Sorcery said:

Gas!

I don't think researching the electricity is worth your time.

It'll be cheaper to just buy a different kiln.

Or go gas!

Sorce

It's worth looking at all the options - and for a small kiln with 3 elements it may not cost a lot to upgrade.  I can imagine a large kiln would be cost prohibitive.  Gas is also a good option, but it can give very different firing results (which isn't always a bad thing :-).

[Mark C. 5,024]

Many of the potters I have seen in New Zealand fire with gas. cone 6 to cone 10.At least the ones in the Neilson Area in the 90s.

[Bill Kielb 1,263]

4 hours ago, toninz said:

It's worth looking at all the options - and for a small kiln with 3 elements it may not cost a lot to upgrade.  I can imagine a large kiln would be cost prohibitive

Really not much to this
If you can get the wattage up to what a typical cone ten kiln of that size requires, you have done it. So as long as you can account for the electrical safety it’s pretty easy to do provided you can find  Cone ten elements wound to a lower resistance. Not really much difference in the shell, the control or even the interior wiring for that matter but confirmation of all being adequate is necessary.

[Sorcery 210]

8 hours ago, toninz said:

years

There's probably nothing harder than changing the oil on a car, so don't be afraid to start getting your experience, especially if it means side $, sounds like it!

All you need is a Multi screw driver, a good multimeter, and a knowledgeable supplier, or multiple good suppliers, to keep with the theme!

If you label wire ends upon removal, you can't screw up.

Turn it off before servicing blah blah blah...

Sorce

 

 

[neilestrick 4,808]

9 hours ago, jrgpots said:

Sorry for the misinformation.

Not at all! I should have explained more: Typically when backup insulation is added to electric kilns it's in the form of rigid board. It's easy to work with and harder to compress. It still can be compressed, though, so they'll use a set of narrow bands around the bricks under the board to keep them tight. But if your bricks aren't rounded at the corners those ands will cut into the brick. The other thing they do is put creases in the outer body band at the corners so they don't get compression of the backup insulation there when it's tightened up.