Denville

In The Kiln Room

Ever wonder what happens when you leave your piece behind?

You know the basics steps. You start by picking out your piece. You create your beautiful design, using everything from straight brushstrokes to sponges to stencils to shaving cream. Then you have to say good-bye to your masterpiece and leave it with us for a week. At the end, you come back to retrieve your completed pieces, now shiny and bright!

But what happens during the week between when you paint your piece and pick it up?

STEP 1: GLAZING

Glazing refers to the process of covering a ceramic piece with an over glaze. Over glaze is a  clear coat of paint meant to be painted over the ceramic paints we use. This ensures that the entire piece will be covered, and therefore will be fired to perfection. After a painted ceramic piece dries, we take it back to our kiln room to be glazed. Each piece is then dipped into the glaze to cover each part of the piece. 

Now we know what you’re thinking: Why are you turning my piece green?

The unfired glaze is colored for a simple reason: so we can see it! We need to make sure the entire piece is covered, and with a colored glaze it is much easier to tell if we’ve missed any spots. But don’t worry! Once the piece is fired, that green color will become the clear overcoat you see on all your pieces.

STEP 2: FIRING

Firing refers to the process of baking a ceramic piece within a ceramic kiln. Firing brings out the true color of the ceramic paint and hardens it into the shiny, glass-like material you’ll see when the piece is completed. After the over glaze dries, pieces are placed into the kiln to be fired. The firing process takes anywhere from 2-3 days, depending on several factors.

First, pieces are loaded into the kiln. The process of loading the kiln requires precision and care.  Ceramic pieces will stick to anything they touch during the firing process: the shelf, the walls of the kiln, even other pieces! Each piece is placed on a stilt to keep it from touching the shelf and is carefully placed to avoid brushing up against other pieces. We use adjustable risers to change the height of the shelves so we can fit as many pieces as possible into each load of the kiln. An average load of the kiln usually holds anywhere from 40 – 60 painted pieces.

Once all the pieces are loaded, the kiln is sealed shut and the firing begins! In the days of old, kilns operated using an actual fire, or the use of coal. Our kilns are a bit more modern: they are electric! All it takes is a few button pushes, and the kilns are off! 

We get a lot of questions about this part of the process:

How hot do the kilns get?

Our kilns fire at about 2,000 F. Ceramic paint requires very high temperatures in order to harden and change color. 

Why does the firing process take so long?

Ceramic pieces are fragile and require a lot of care. Pieces that are heated up too quickly or that cool too fast can crack, or even explode. The kilns are specially design to heat up and cool down at the best rate to ensure the safety of the pieces inside. The entire process usually takes 2-3 days. The weather, the amount of pieces in the kiln, how tightly packed the kiln is, and several other factors all work together to affect how quickly or slowly the kiln will heat and cool.

What happens if it doesn’t fire long or hot enough?

The short answer: nothing. If the ceramic is not fired long enough, it cannot reach the correct temperature to properly fire. If the piece does not reach the proper temperature, the paint will not harden correctly or gain its true vibrancy. It will have to be refired in order to fix the piece. 

Can I just use my oven at home?

Unfortunately, a conventional oven is not built to handle ceramic pieces. For one thing, conventional ovens do not reach the required temperatures to properly fire the ceramic. For another, it cannot correctly heat and then cool the ceramic pieces.

STEP 3: UNLOADING

This is our favorite part of the process! Once the kiln has cooled, its time for the completed pieces to come out of the kiln. Each shelf is unloaded one at a time. As each piece is removed from the kiln, it is checked over for any flaws. 

Once the kiln is fully unloaded, pieces are organized and prepared for transportation. Pieces are sanded to remove any marks left behind by the stilts. Once sanded they are individually wrapped to help protect them. They are then packed into bags by ticket, and filed away to wait for pick up.