This past summer we decided to experiment with a cob
door for the rocket cooktop at the abbey to use in place of the current cast iron skillet
The first photo shows the cob
door right after it was made.
Whoops! Today the door got knocked off the cooktop and broke into several pieces, as seen in the second photo.
Now, with a view into its interior, i was able to see how it stood up to the heat. With use the cob
was "dusting" every time i opened or closed the stove, so i decided to use linseed oil on the cob (like the rest of the stove), so that it wouldn't make such a mess. Well, most of the rest of the cob is covering bricks that are insulated from the heat. So this bit of cob had a different experience
. I used two applications of linseed oil. I didn't use it on the hottest interior part (that would be in direct exposure to the flames), but around the inner edge where it was touching the stove.
In the next couple of photos you can see the depth of the oil penetration. The cob in the middle of these pieces seems like normal reusable cob.
The last few photos are of the parts exposed to the most heat. Here, the cob looks a bit like terracotta. There were a couple of days early this fall when i did a different experiment where i got the stove as hot as possible...hotter than it would be in normal cooking use. During those tests, the straw
on the outside of the door was starting to darken with charring. The straw on the inside was completely burned out. I think if i had just used this door with normal operation, most of the straw would be intact and the door could have survived the drop.