How do I choose a kiln?

[Pir]

Hi, I am stumped on how to buy a kiln. Be warned, I am very green when it comes to kilns, as these questions will betray!

My first question is this: when I see a kiln as advertised as Max Temp: 1800, what cone does this reach? Is it the case that 1800 degrees + time can reach a higher temperature/cone, or does max temp translate directly to a particular cone? (This relates to a small programmable glass-fusing kiln I see on Marketplace for $450, a Skutt GM-814--the price and size are attractive, but does this reach cone 6?)

Next: How does one determine if they need a single or 3-phase kiln if they don't know where the kiln will eventually go?! My studio circumstances are likely to change soon (new owners bought the building, making "improvements," raising rent, etc.). I understand a 3-phase can work in a building with a single or 3-phase setup, but a single-phase will not work in a building with only a 3-phase, I think, right?

More generally, having never much used an older kiln sitter, and having some experience with a fancy programmable Skutt, I am naturally leaning toward the latter. I'd be interested in various ramps/holds, slow cools, etc., and I just don't know how (or if) that is done on the older types.

Then again, I am not a production potter (not yet anyway, and I don't know if I want to be one), so I am an amateur, and I can probably live with a simpler, cheaper kiln to start. This makes me wonder about size, too--smaller size might be better, as I like making and testing glazes (at least for now). 

And then there's brand: Someone suggested L&Ls are best (and that replacing elements is easy on these)--might an older L&L be as good as a newer programmable Skutt?--and another person said they wouldn't buy a Paragon.

I'm always seeing kilns on Facebook Marketplace (for Rochester, NY), but "it's all Greek to me."

Advice is warmly welcomed.

Pir

 

[neilestrick]

1 hour ago, Pir said:

My first question is this: when I see a kiln as advertised as Max Temp: 1800, what cone does this reach? Is it the case that 1800 degrees + time can reach a higher temperature/cone, or does max temp translate directly to a particular cone? (This relates to a small programmable glass-fusing kiln I see on Marketplace for $450, a Skutt GM-814--the price and size are attractive, but does this reach cone 6?)

If you plan to glaze fire to cone 6 (2230F), then you want a kiln that can fire to cone 10. That way your elements can wear quite a bit before they need to be replaced. A cone 10 kiln will get about 40% more element life than a cone 8 kiln when firing to cone 6.

1 hour ago, Pir said:

Next: How does one determine if they need a single or 3-phase kiln if they don't know where the kiln will eventually go?! My studio circumstances are likely to change soon (new owners bought the building, making "improvements," raising rent, etc.). I understand a 3-phase can work in a building with a single or 3-phase setup, but a single-phase will not work in a building with only a 3-phase, I think, right?

You order the kiln according to the electrical service in the building. You can run a single phase kiln in a building that has 3 phase service. You cannot run a 3 phase kiln in a building that only has single phase service.

1 hour ago, Pir said:

More generally, having never much used an older kiln sitter, and having some experience with a fancy programmable Skutt, I am naturally leaning toward the latter. I'd be interested in various ramps/holds, slow cools, etc., and I just don't know how (or if) that is done on the older types.

There is no good reason to buy a manual kiln. Get a digital kiln, and get the new touch screen controller. They're easier to program than the old controllers, are more user-friendly for custom programs, and make diagnosing problems a lot easier.

1 hour ago, Pir said:

Then again, I am not a production potter (not yet anyway, and I don't know if I want to be one), so I am an amateur, and I can probably live with a simpler, cheaper kiln to start. This makes me wonder about size, too--smaller size might be better, as I like making and testing glazes (at least for now). 

It's not a bad idea to have a small kiln for testing or small batches, and a larger kiln for producing work. You have to have the proper electrical circuit run for each one, though, so buying a small kiln now and a larger one later can get expensive in electrician costs.

I would not buy anything until you know where you're going to put it. The electrical requirements are different for every kiln, so you first have to make sure that the electrical system in your building can handle the kiln you want.

 

[Pir]

Thanks very much, Neil.

Given the greater power and efficiency of three phase vs single phase (according to what I'm reading), and assuming the building is set up for it, should one aim for a three phase?

Thanks again,

Pir

 

 

[Denice]

When I graduated from college with my ceramics degree my professor said I should buy a test kiln  for my glazes.   Cone 6 oxidation glazes were fairly new and would need testing on different clay's.   My husband said to consider it a graduation present.   I recently bought a new Paragon Caldera XL test kiln to replace my old AIM kiln.   My old one doesn't have a computer  and the walls are on the thin side.   It cools really fast which can change the glaze.  The need to test glazes is even greater with the substitution of different ingredients in a glaze formulas today.   The best compliment  on my glaze work was from another potter.   I was dropping off  a load of pots at a gallery,  another potter was there watching me.  She came up to me as I was about to leave and said to me that I really paid attention to my glaze.   She said each pot had the right glaze for it, if it had two glazes they were applied at just the right level and the glazes were perfect.   Her comments to me were so much more valuable than anything I sold.  I didn't think anyone gave a second thought to the glaze, for me a glaze can make or break it.   Denice

[neilestrick]

45 minutes ago, Pir said:

Thanks very much, Neil.

Given the greater power and efficiency of three phase vs single phase (according to what I'm reading), and assuming the building is set up for it, should one aim for a three phase?

Thanks again,

Pir

 

 

When we look at the power that a kiln has, we look at the wattage. For instance, a Skutt KM1027-3 or L&L e23T-3 on 240 volt service pulls 11,520 watts whether it's on single or 3 phase. Watts are what you pay for, so the cost of firing will be the same whether on single or 3 phase. Where the difference comes in is that 3 phase allows you to achieve that wattage with lower amperage. A typical breaker box can handle up to 200 amps, so on 3 phase you can hook up more stuff before you max out the box. A kiln that will pull 48 amps single phase service will only pull 28 amps on 3 phase since you're diving the pull between 3 wires instead of just 2. So if you were hooking up multiple kilns you could do 3 kilns on 3 phase and use fewer amps than 2 kilns on single phase.

The math from single to 3 phase is to divide the single phase amperage by the square root of 3 (1.73). 

Another place you'll see a benefit of 3 phase kilns is in some 10 cubic foot kilns that are meant to be plug-and play (don't need to be hardwired). In order for a kiln to have a plug it has be under 50 amps. If you look at the Skutt KM1227-3 or the L&L e28T-3, they pull 48 amps on 240 volt single phase service, which means they only have enough power to get to cone 8. But 50 amps gives you lots of room to add more power on 3 phase service, so L&L takes their 240 volt 3 phase kiln and bumps it up to 16,600 watts, which is only 40 amps on 3 phase, which gives it more than enough power to get to cone 10.

3 phase power can be less expensive and easier to install because the lower amperage allows for smaller wires, disconnect boxes, fuses, etc. So to answer your question, yes, get 3 phase is if it's available.

[Bam2015]

Pir, when it comes to kiln selection, heed Neil's advice. Neil knows kilns.  

Betty

[Pir]

12 hours ago, Denice said:

She came up to me as I was about to leave and said to me that I really paid attention to my glaze.   She said each pot had the right glaze for it, if it had two glazes they were applied at just the right level and the glazes were perfect.   Her comments to me were so much more valuable than anything I sold.  I didn't think anyone gave a second thought to the glaze, for me a glaze can make or break it.   Denice

Thanks, Denice, Yes, I find that we are our own harshest critics of our work, and I attribute that to expectation: when our expectations about a glaze--how it should turn out--fall short, there is dissatisfaction...but often, for me, as time passes and the memory of what I expected grows dim, I can see the piece/glaze differently, and actually come to appreciate it.

Pir

[Pir]

12 hours ago, neilestrick said:

3 phase power can be less expensive and easier to install because the lower amperage allows for smaller wires, disconnect boxes, fuses, etc. So to answer your question, yes, get 3 phase is if it's available.

Hi Niel, Thanks again. This encourages me to hold out until I can get something close to the best option for me, rather than settle for something older, less user-friendly, more costly, etc.

Best, Pir

[Pir]

Can I also ask: how important is ventilation for a kiln? I'm assuming VERY. I've come across some studio options that look good except they have no easy way to vent. At worst, I'd guess one would simply have to be out of the room while the kiln is cooking... Or is it worse than that? i.e., lingering fumes, fumes drifting into other parts of a building, etc.

Pir

[Denice]

All to familiar with being the harshest critic of my work,   I usually give away the pots I am not completely happy with to visitors  in my studio.  They usually pick the one I really dislike.    I wasn't unhappy with the work I was taking to the gallery,  I was just surprised that anyone notice how hard I worked with glazes.   Denice     Good luck with the kiln purchase.

[neilestrick]

1 hour ago, Pir said:

Can I also ask: how important is ventilation for a kiln? I'm assuming VERY. I've come across some studio options that look good except they have no easy way to vent. At worst, I'd guess one would simply have to be out of the room while the kiln is cooking... Or is it worse than that? i.e., lingering fumes, fumes drifting into other parts of a building, etc.

Pir

IMO venting is required. A downdraft vent will increase the life of your elements and generally make glazes look better, in addition to saving your lungs. Even if you're not in the room, all that tiny particulate matter that's in the fumes will be landing all over everything in your studio, which isn't good. A downdraft vent only vents fumes, though, so depending on your setup you may also need a way to vent the heat coming off the kiln. That could be as simple as cross-ventilation between two windows, or a fan in a window near the kiln. Vent-A-Kiln makes a great overhead hood that pulls out heat and fumes, and is a good option if you need both. Vents need a path to outdoors, so that may mean drilling a hole in the wall or roof, of you can rig up a board in a window, either temporary or permanent.  Sliding windows are easy to fit a plywood board into when the vent is in use. For a permanent setup you can remove the window sash completely and install a board. Here's an example of a semi-permanent board that's wedged tight against the window frame, with weatherstripping between them for a good seal:

[Pir]

3 minutes ago, neilestrick said:

IMO venting is required.

Thanks once again, Neil. Lots of work ahead of me!

Pir

[neilestrick]

Used kilns are always an option, you just need to make sure the bricks are in good shape. Everything else can be replaced fairly easily if you're somewhat handy. Manual kilns can be converted to digital, but expect to spend about $1000 to do so.

[Pir]

7 minutes ago, neilestrick said:

Everything else can be replaced fairly easily if you're somewhat handy. Manual kilns can be converted to digital, but expect to spend about $1000 to do so.

I'm definitely not that handy!

[Denice]

That is a great looking  job on venting the basement window.   I didn't have any windows when I had my basement studio (dungeon) but I did have a dryer vent that went outside.  My husband reconfiqured the vent to where I could run a  a  vent to it when I fired.   He installed a baffle that I could use to block the main vent off to the dryer while firing.  When your house is 100 years old and it has a double brick  twelve inch thick wall  you have to be creative.    Denice

[oldlady]

pir, there is one other thing that you should consider.   how tall are you and how far down into the kiln you buy can you reach?   can you load shelves and pots easily today?   for 20 or thirty years in the future?  

L&L  now makes one that is wider than it is tall.   i wish i had one.   at 82 i find putting things on the bottom shelf, which is raised off the bottom of the kiln by 2 inches, is getting difficult.  if you are going to pay for a new kiln, remember how long they last with reasonable use.   notice when you see one close up that your fingernail will indent the brick if you just push your finger in.   and yes, the new discussions of kiln size talk about cubic feet.   ignore that and get the depth and width and shelf size. that is what matters.  the size of an acre is 43,560 square feet.  the shape matters, you cannot build a house on a 2 foot wide by 21,780 feet long acre.

L&L makes an easy to maintain kiln, those hard brick channels saved the day often when i unloaded a heavy shelf and smacked the wall.

to learn about kilns look at your local library section on pottery.   lots of junk about collecting old stuff, avoid that and get to the ones that are textbooks.  there is a very complete list somewhere in the archives here.

Edited November 18, 2022 by oldlady

[Pir]

14 hours ago, oldlady said:

pir, there is one other thing that you should consider.   how tall are you and how far down into the kiln you buy can you reach?   can you load shelves and pots easily today?   for 20 or thirty years in the future?

Thank you, Oldlady! The studio manager--mid-20s--of the arts center where I bring my stuff to be fired is recovering from a back injury, which he attributes to loading/unloading.

I've never thought about bricks and how they are damaged--though I've noticed most used kilns seem to have brick gouges and damage.

And I keep hearing positive things about L&L. 

Pir

[oompafoxfernpeas]

Choosing the right kiln for your project depends on the type of material you are firing, the size of the items you are firing, and the type of firings you are doing. If you are firing ceramic pieces, you should look for a kiln that is designed for ceramics and can reach the temperatures you need, depending on the type of glaze and firing you are doing. If you are firing glass, you should look for a kiln specifically designed for glass, such as a glass slumping kiln. If you need to fire large items, look for a kiln with a large interior space and door opening. If you are doing small-scale production work, look for a kiln with multiple shelves to maximize your firing capacity. Lastly, consider the type of fuel you need for your kiln. Electric, gas, and wood-fired kilns are all available and the fuel type you choose will depend on your project and budget.