Glassy coating on inside of lid

[Larry D.]

The shiny coating that develops on the inside of the WSM lid has been mentioned many times in the past. This morning, after several days of heavy rains, I took the cover off my WSM to see if any water had accumulated inside (only a little had, no problem) but I was surprised to see that the coating on the inside of the lid had apparently somehow been converted to a very light, brittle, puffy ash material (about the consistency of the outside of a burned marshmallow). After removing this stuff, and a light brushing with a wire brush, I was practically down to the bare porcelain. Here's a poor quality photo of the ash:

It's so brittle that picking up the large piece by one edge would result in its breaking under its own weight. Has anyone else ever seen this?

 

[Bob Correll]

We recently received alot of rain, 5" over a 2 day period..
My Performer was covered, but the moisture loosened up the same looking stuff from inside the lid.
Thankfully it fell on the grate before the meat went on.

 

[Bill Elwell]

Interesting. I've never seen that on mine. I get a light rusty looking coating in my lid. It's probably the result of some after cook condensation. I clean much of it out by rubbing it with some balled up newspaper. I don't try to clean it all out, but there's a lot less remaining come smoking time. I think some soap and water might do it though.

FWIW, I clean my WSM after every use and store it in the garage intact and covered.