I've a new Q3200 and after each BBQ while cleaning the grill with a wire brush those brown stripes appear:
(http://images.tapatalk-cdn.com/15/07/16/3a6fc819cd20123e9eba6246730b6381.jpg)
It had never contact with water and I coat it after each clean after each usage.
Has anyone a clue what this is? Is it really rust?
No rust, although you may be scraping it a bit too hard. Put some oil on a rag and wipe it down and you should be fine.
Even though it is porcelain coated oil still makes a difference.
Thanks, this let me sleep better ;-)
And I already coat it with oil after each usage. (Did miss somehow the word "oil" in my first post)
I have a Q 3200 for over a year, I know Weber says it is okay to use a wire brush but I would not use it. Since the grate is in 2 pieces let the grates sit in your kitchen sink in very hot water and soap. After about a half hour when the water cools you can wipe most things off with a sponge, a Brillo pad can get the rest especially underneath. This works for me and keeps the grates looking like new. I clean them after each use. I tried a wire brush once and I think it would eventually cause damage to the grates.
Thanks for the tip, I'll try it also next time.
My theory is the grates develope a polymer coating ( seasoned) over time.
When warming I knock off the chunks with a brush but don't clean otherwise
Well it's also a question of logistics how to clean the grate. I realized it's not possible for me to clean it the way suggested by BBQ Jack. I've just a allotment garden here in Germany without sink or waste water. However, my current theory is, the brown particles may be simple magic dust I used. Because it increased after I recently used a lot of magic dust dry rub. If so, I'm happy :-)
I had the same thing and yes it is rust... from your wire brush. After you clear the big chunks with a brush wipe off with a paper towel with a little oil on it and it will look like new. I guess the thickness of the grates allow for a larger "palate" for the color to be visible, I never noticed it with any of my kettles.