<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Vince Ser:
I got the weber grates. Maybe it has to do with the porcelain coating? </div></BLOCKQUOTE>
Ahh, so if you have ENAMAELED cast iron - yes I would be careful. You can use metal but risk chipping the porcelain/enamel. That will cause rusting and eventual bubbling, flaking of the coating over time.
So use wood or plastic. If you use metal just be careful not to bang or dig in vertically. As long as you have a nice horizontal motion and are not forcing you should be OK.
I had enameled wire and cast iron grates in the past on various cookers/grills. They lasted a really long time and I was using metal implements. The deal is you don't want to chip the coating and allow water/elements to get in and rust the CI underneath. It's really the same with enameled wire grates too. They will rust underneath the coating if water/moisture can find it's way in.
Uncoated black cast iron grates are better IMHO since if they rust you can restore and re-season readily. Same with black cast iron holloware.
Once the enamel fails on coated items you will have a slow but continual degradation over time. Not a big deal, just something to know. Enameled has it's benefits, but we are talking about one of it's deficiencies here.
In the end AFA cooking grates they are generally easy and relatively cheap to replace. The issues we are talking about here would take years to have an effect to the point that made the grates unusable. So in the end I would just take normal care and not worry about it.