21 Kiln Questions Answered

a image of a potter next to a kiln

Whether you have a Kiln or thinking of getting one, there are some basic things you want and need to know to get the best results from the beautiful pottery you have just created.

When you get your first Kiln, there is a lot of excitement and little nervousness. After all, you just bought a giant oven. Maybe not size-wise but certainly heat-wise. Some useful knowledge can put your mind at ease.

I Put Together A List Of 21 Of the Most Frequently Asked Questions About Electric Kilns.
My 21 Answers Come to You from My Personal Experience, Other Kiln Owners, And the Very Helpful and Informative Technicians at Skutt.

The first and one of the most important questions:

1. Do I Need an Electrician to Install My Kiln Outlet?

a picture of a kiln plug

Yes. I would recommend Installing your Kiln as per the manufacturer’s instructions and your local fire and electrical safety codes. This is the area you never want to get cheap on.

Using a qualified technician keeps your insurance coverage valid,  just in case something goes awry. When it comes to electricity, you do NOT want to take any chances.

Before you purchase an Electric Kiln I strongly suggest getting a Licensed Electrician to check and make sure you can safely operate the kiln you are thinking of purchasing. For this reason, I have found that Home Advisor (affiliate link) is an excellent choice for hiring an Electrician to ensure the safe and correct installation of any wiring, breaker boxes, or outlets.

After signing up for Home Advisor (no charge) up you will be connected with multiple contractors in your local geographic area.
You will then be able to ask your contractors questions to see if your Kiln is compatible with your electrical system before even setting up an appointment.

I had my Garage wired for my Skutt 818 Kiln and it took less than one hour.

2. Do Kilns Use A Lot of Electricity?

This would Depend on the size and age of your Kiln. Larger or older kilns will use more energy. A Kiln with thicker bricks will be more efficient. My medium-sized Skutt 818 with the 3-inch brick costs around $3 for a Bisque Fire and $5 for a Cone 5 Fire. Which will give you some idea of the pre-fire cost.   

3. Should I Get A Used or New Kiln?

a picture of a Skutt KM - 818 - 3 kiln
a picture of a used cress kiln

The choosing of a new or used kiln would go with both your budget and knowledge of Kilns.

 Do you know what to look for in a used Kiln? When getting a used Kiln, think of delivery and what questions to ask, and what to look for in a kiln. I would not recommend buying a kiln sight unseen. 

Kilns, for the most part, are built well and last for a very long time. You can get a good used Kiln for a reasonable price.

Read this Step-by-Step Buyer’s Guide to help you Choose the Electric Kiln that’s best for you.

Now even if you have been making pottery for a while you can still be unfamiliar with the running of a kiln. For instance, if you had a kiln at a school or a studio where they did not allow you to use the Kiln. So you have barely looked at Kiln, let alone fired one up. I would put my wares on a shelf, and the finished piece would magically appear a week later.

So if you are unfamiliar with kilns and thinking of getting one, I think a new one is worth the investment.

They are very easy to run, more energy-efficient, and you would have the newest technology. You also won’t have to mess with fixing or replacing anything for a while.

If you decide to buy a new kiln, you can check my article on Buying a Kiln for Facts, Features, and What to Consider.

4. Can I Use My Kiln Right Away?

If it’s Used, You should use a pyrometric or witness cone for a bisque fire.

Fill your Kiln with your shelves and posts only, then bisque fire. If your witness cone is correct, you can begin to use your Kiln. If not, MAKE the proper adjustments then fire her up.

If it’s a New Kiln, again, NO. First, you must do a cone 04 bisque fire with the shelves and posts only to burn the oils off the elements. This process increases the life of your elements. You also want to use a witness cone to make sure the temperature is accurate.  Even if you have a new kiln, you still need to make sure it fires to the correct temperature.   

5. Do I Need A Vent for My Kiln?

If there is little to no ventilation, and your Kiln is larger and giving off too much heat, then yes, you need an Overhead vent for your Kiln.

You don’t want your control panel to overheat. If the control board on most Kilns reaches over 160 degrees, it will shut down during the firing. You want to keep your Kiln studio area below 100 degrees during firing.

Overhead vents will draw the fumes and heat out of your kiln area But will not bring oxygen in the Kiln.

There is also a vent you can get for the bottom of your Kiln. This vent will draw the fumes out and bring oxygen in, but will not be efficient in drawing the heat out of the Kiln area. 

So if you have fresh air coming in your kiln area, you don’t need a vent.

6. If I Have No Vent, Should I Be Concerned About Fumes in My Kiln Area?

If there is fresh air coming in and your not hanging around the kiln area, you should be fine. Most of the organic material from the pottery burns off between 500 and 1200 degrees, which will last about 3 to 5 hours depending on how slow you fire and big your Kiln is. Keep in mind the Fumes will still be coming out of the Kiln but at a much slower rate.  

I have the garage door a quarter of the way up, and I never smell anything in the house. Just make sure your kiln area is not in your living area.

7. Do I Need A Stand?

a picture of a kiln stand

If you don’t have a stand, get one or put it on cinder blocks or something like it as long as it is not flammable. You do not want your Kiln on the ground.  You will not get adequate airflow on the bottom. Even if it’s on a concrete floor, the concrete will crack. So it’s best to have a stand.

8. Should I Keep the Peeps In All The Holes Or Not?

a picture of peepers

I was told many different ways to do it. Then I was told by several Skutt technicians if you have a vent on the bottom, then yes, you should keep all your peepers in.

If you have no bottom vent, then you should keep the top peep open throughout the firing. This allows the fumes and fine particles to escape, so they don’t settle back on your pottery and elements.

It also brings oxygen in the Kiln and burns cleaner, which helps give you more vibrant colors and better results. 

It also increases the life of your elements because the fumes and fine particles are not settling onto you’re the elements.

9. If I Keep the Top Peep Open, What About Thermal Shock?

The Kiln is powerful enough to handle one peep out, but not all of them. So the golden rule is to keep your top peep out and in a drawer.

10. I Still See Glowing In My Kiln, Are the Elements Still On Because
The Kiln Says Complete,

When the Kiln says complete, it is still glowing inside, but that’s not the elements it’s your pottery glowing like pieces of lava. The elements have turned off, and your Kiln is cooling down naturally.

Unless you program it for a slower cool down then the elements will turn on to assist in cooling it down slowly.

11. Can I Lift the Lid While the Kiln Is Still Hot?

a picture of a mit on a hot handle

No! Besides sheer curiosity, there is no reason to lift the lid. Since you can’t do anything with the pottery until it is cool, leave it alone. If you do lift up the lid, you take a chance of ruining our pottery. You can cause thermal shock, crazing, and even cracking.

12. How Long Does A Firing Take from Beginning to End?

Now this will depend on several things. How big is your Kiln? How thick are your bricks? If you programed your Kiln for a slower fire and or slower cool down. So the time will vary.

I can tell you how long my Kiln takes. It is a smaller kiln, only 2.3 cubic feet of space and 3-inch brick. It takes around 36 hours from beginning to end (room temperature). For the best results don’t open until it’s at 125 degrees or room temperature.

13. Is 3-Inch Brick Better Than 2 And A Half Inch Brick?

a picture of kiln brick

The 2 and a half inch brick gives you more space in the Kiln and also costs less. 

The three-inch brick is more energy-efficient cools down slower, which is always good for ceramics. And the control board is more protected from the heat of the Kiln, which would take it much longer to hit 160 degrees.

You will lose a little space with the 3-inch brick. The 3-inch does cost more but can cost less in the long run. 

With that said I would personally go for the 3-inch because the pros do outweigh the cons.

14. Do I Need a Touchscreen Controller?

a picture of a touch screen controler
a picture of kiln controler temperature

You definitely do not have to, especially if you like the old school way of working a kiln. But if you are new at working with kilns and want the luxury of having a 21-century computer touchscreen, then I would say yes get one. I love mine. The Skutt technicians have access to my controller and can help me with any troubleshooting. You can update it, and it is so easy to program.

A computerized controller does give you more control over your firings

You can watch this Video on Programing the Skutt Kiln with the touch screen controller to see how easy it is to use.

15. Do I Need to Use Witness Cones Every Time I Fire?

Witness cones, also called Pyrometric cones, play a crucial part in the accuracy of the temperature in your Kiln. Even if you have a newer kiln with a computerized touch screen, you still want to make sure it is accurate. So you still need to use a witness cone, but not as often.

Definitely use witness cones from time to time to ensure your Kiln is running correctly. If you have an older kiln, yes, you should use them more often. An older kiln should be checked every 4 fires. Some potters use them in every firing.

You will also want to place them on every self to see how evenly your Kiln is firing.

16. Should I Slow, Medium, Or High Fire My Pottery?

Slow fire is the way to go. Medium fire is the most popular and works fine with most clays and glazes. You can high fire, but it is not recommended. It does not allow time for your glaze to cure. Only high fire if you are working with glass alone. I would recommend doing a slow bisque fire because it will ensure all the organic mineral is burned off and causes fewer problems in the glaze fire. Then you can go ahead and glaze fire on medium or slow if you like. 

17. Do I Have to Use Kiln Wash?

a picture of kiln wash and cookies

If you don’t have top of line Kiln Shelves or use cookies, then I would definitely use Kiln wash. Keep in mind the kiln wash will start to flake off, and you have to Reapply by Scrapping off any glaze drippings and flaking kiln wash then reapply kiln wash by dabbing some on the bare spots.

If you use choose to use kiln wash, it’s essential to maintain it. You don’t want the kiln wash to flake off and possibly float right on one of the pieces that you spent so long creating.

If you use cookies, make sure you use cone 10 clay with heavy grog. They last longer and shrink less with the heavy grog.

I also have an article you can read on Protecting Your Kiln Shelves From Melting Glaze.

18. Should I Be Concerned About Cracks on The Bottom of My Kiln?

If your kiln was delivered with cracks on the bottom you should call the manufacturer right away. If it has small cracks after several firings that is normal from the heat expanding and contracting and should not crack any further. My small crack has stayed the same for over a year.

You should be concerned if you are choosing a used kiln and the crack goes all the way across the bottom. Or if the crack goes all way through and you can see light through.

Never ever, ever, ever, put anything on the bottom of your Kiln. No air can flow through.  You need to place at least One-inch posts on the bottom of your Kiln. This will give you enough room for the air to flow through on the bottom.

19. Should I Put A Hold on When I Glaze Fire?

You don’t have to put a hold on, but If you want to make sure the temperature is even throughout the Kiln, you can put a 5-minute hold on at the end of the firing, this also helps the glaze to cure.

On digital kilns, you can easily program a hold at the end of the firing for 5 to 10 minutes. If you don’t want to or can’t put a hold on your Kiln, you can also slow fire if you like.

  I have a friend that has a manual kiln that she literally had to manually hold at peck temperature for 5 minutes. I can happily say she bought a touch screen controller for it.

20. Does My Glazed Piece Have to Be Totally Dry Before Placing It in The Kiln? 

It is best to allow your glazed piece to dry thoroughly. Kilns hate moisture. The less moisture in your Kiln, the longer it will last.

21. How Often Do I Have to Vacuum?

I would recommend vacuuming after every bisque fire. The reason being there is clay dust still floating around from the bisque fire, and you know this because you are washing the fine dust particles off your bisque ware. So you know there must be some clay dust left in your Kiln. You don’t want it floating onto your glaze during your glaze fire.

After spending all of that time creating decorating and Glazing your pottery, it is totally worth taking the 5 to 10 minutes out to vacuum and increase the success level of all that pottery in your Kiln.  


The 21 Kiln Questions Answered are only a fraction of what you will eventually learn with each firing of your own kiln.
When it comes to the purchase of a new kiln or to buying a used one there are a lot of things to think about.

Now that you have learned some basics to run and maintain your newly acquired kiln you can have the confidence to get the best results on the pottery you have crafted.



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