What’s the difference between Orton self-supporting cones and large cones

Large cones vs Self Supporting cones

Question: Orton temperature equivalents – I thought self supporting and large cones were interchangeable, but the table shows slightly different temps for the same rate. How critical are those differences?

The Orton Cone Chart can be confusing

In my free Strategic Glazing class, I shared the Orton cone chart, which has the temperature for each cone. So for cone four, cone five, cone six, the temperature that you need to program your kiln to in order to reach each cone is different depending on the rate of temperature climb for the last 200 degrees Fahrenheit of your firing.

And on the cone chart, there are different temperatures depending on whether you’re using large cones where you make a cone pack, or self supporting cones where they just stand up all by themselves. The difference in temperature isn’t that big. All the examples I shared were within ten degrees Fahrenheit of each other. It wasn’t a huge difference.

So there are differences between using the large cones and the self supporting cones but I don’t think it’s big enough of a difference to be a problem or to have a huge impact on your glaze results. I would probably just use them interchangeably, although I’ve never tested.

Testing is the best way to know for sure

That would be a good thing to try, is to put a cone pack and self supporting cones next to each other in the kiln and compare how they look at the end of the firing. Compare the way they bend. One might be bent so it’s pointing horizontally and one might be bent where it’s pointing down. If they’re side by side in the kiln, both would represent the same amount of heat work. Then you’ll know that’s what you’re aiming for with each type of cone so you could switch back and forth between large cones and self supporting cones.

Doing a test is always the way you can get really specific answers to these types of questions.

Join my free community

If you love learning about and discussing glazes, I'd like to invite you to my free social learning Facebook group called Understanding Glazes with Sue. The group is full of videos and discussions about firing, mixing glazes and fixing various glaze issues. Please join!

What You Need to Start Mixing Glazes from Scratch

Are you interested in learning how to mix your own glazes? When you start mixing your own glazes from scratch, your glaze options become infinite. Not only will you be able to stand out with unique glazes that you created yourself,  but you'll also start to develop a more intimate relationship with the materials you are using to make your pots.

But before you take the plunge into the world of glaze mixing, you might be wondering what tools and supplies you’ll need to have in your studio. Watch my free "on-demand" class to find out! Click the button for all the details.

Learn to Mix Glazes from Scratch

If you’ve never mixed a glaze from scratch before and want to learn, I teach an online workshop called Glaze Mixing Essentials where I show you all the steps to mix a glaze and then test a base glaze with multiple colourants. Click the link for all the details.

Register now.