The company/person I had making Cordierite Rods and kiln parts suddenly went out of business about two years ago and I have not been able to find suitable replacements for his expertise and products. I am not going to completely dismantle this page yet as some parts are still available. We have plenty of #5 Donuts and 1/4" Mulite rods. But the other stuff here is limited.

The Ceramic Rod Support System:


Welcome to our insulators page. At Joppa Glass we make a lot of elements for kilns and furnaces. This page is dedicated to showing how these ceramic insulators can aid in the safe installation of your heating elements. Without these items we would pretty much be stuck with the grooved brick method, but here you will see how you can literally put an element anywhere, like over your door in a tight corner or all across the ceiling.

Please look at this file which gives a lot of ideas about ceiling installations.

rods for sale

We have several sizes of rods that can be used for internal support of the elements to keep the element snugly in place.

The first rods I sold were the 1/4" Mulite. These were great for small heater units or bit boxes, but we started putting them into large kilns of 50 to 100 cubic feet. They sometimes broke from the shear massiveness of subtle movement, like when the lid would open and close. This was trouble!! So I fould these terrific cordierite rods that are 1/2" in diameter. They are beefy and really hold up to a lot of abuse. If you are building something big use them. If for some reason you want something a little more delicate use the 3/8" material.

The great part about the large diameter material is it will support a small element as well. Because it is a large diameter the smaller elements will fit over it and allow us to put a lot of heat in a small area, neatly held in place. There is a relationship between the rod and donut and element wire thickness. If you are interested please view the donut card.


Our Donuts

(click on image for greater detail)

Please study the Donut Card to see the wide varity of support material we offer you.


Electrical Connection Boards for the Element Leads

(click image for more detail)

More Examples



Mounting the Cement/Fiber Connection Board

The cement/fiber board is mounted using sheet metal screws or pop-rivits. Fashion the brackets from something like 18 ga. aluminium. If you don't have a metal break use a pair of boards to clamp the metal to, then form the shapes as shown. I usually use the "S" bracket as that is the easiest to screw to the wall. This bracket also serves as a vertical cooling tower along the side of the kiln. Study the images from page 4 of How to Build Your Own Controller.

Our "Thru" Tubes

(For insulating the element leads as they go through the kiln wall, especially through the metal shell.)