October 20, 2008


Spy openings with thrown spy plugs in place.

Joe Cole asked about my spy "plugs" and I sent him some pictures. I thought you, readers of "ye olde blogge", may be interested as well. After all the pictures are handy and inquiring minds want to know. The word spy,[ME, circa 1200-1250], has an intriguing allure, doesn't it? Well I guess you could say peeking, but spying is what we're doing when we look through one of these. We're definitely on the lookout, we're definitely keeping watch of the fire, the pots, and the cones.
The open spy.

The main reason that I made these spy plugs is that when I built the arch form I decided to use 3" PVC pipe to create the voids in the form to be poured with refractory concrete. Since I was looking at Mark Peters' kiln as a model I did the same thing he did. I also thought they looked cool, too. I later found out that it was hard to find a single soft brick that could be cut to form a plug, and that gluing two bricks together didn't work after trying for the first firing. So for the second firing to the present I have used these thrown plugs. I don't remember what clay I mixed up, maybe fireclay, but I do remember putting a little bit of alumina in the mix, as well as sand, and a little sawdust.

Side view showing the plug handle.

After throwing the plugs I decided that a nice pulled handle would make it nice for pulling the plug. I have seen these types of spy plugs with a flange around the top edge so that it can be handles with a nearby stick, but that seemed too complicated, I guess. I love pulling handles so that is how I made them.

The spy plug showing divets.

I decided to use a drill to make divets so that the plugs didn't weigh so much, and then I filled the void the a little ceramic fiber. Once a plug broke during a firing and I scrambled to find something to use in its place. There happened to be a tumbler nearby that didn't make it into the kiln and I used that in the pinch. As a matter of fact I think it's still in the kiln in an unused spy hole.

I digress.

Since then I've made a couple of extra plugs to have around in case another one broke. But it hasn't happened.

I guess that's it. If you have questions, I'm happy to answer. Just leave a comment and I'll try to get back to you. If you haven't registered with my commenting service, Disqus, do so and you will be alerted by email. Your email address won't be made public. Thanks for reading this obscure post.