rust on cooking grid

My wife and I bought a Thermos Quick Start grill last year, one with a porcelain cooking grid. I have been very particular about taking care of it - seasoning, cleaning, etc. - because my wife's grill (before we got married) had more rust on it than a junkyard.

But here we are just about one year later, and the cooking grid is rusting, first in the back center over a hot spot, then slowly spreading to cover just about the whole center of the cooking surface. I am at a loss as to why.

Don't know if any of the following would be causes or have an impact: we've used the grill at least weekly since we bought it (including through the winter, though not during the Valentine's Weekend Big Snow), I season the grill with a fine mist of canola or other vegetable oil sprayed on when I first light the grill, and put another coating on after the grill has cooled a bit (it softens some of the ashy gunk for removal the next time), the grill cover was shredded by Spring and we went about 5-6 weeks without a cover, during the wettest April and May in memory (28 out of the 31 days in May we had rain in Baltimore), for cleaning I stopped using the synthetic scrunge-type pad and have been using a brass soft-bristle brush.

I've approached this grill as I would a cast iron skillet or other valuable stove pan, wanting to keep it well-maintained and seasoned, not abused. But I worry I've abused it in the process. I don't think the brush has scraped through the porcelain coating because the rust is only in one (spreading) patch rather than across the cooking grid especially in the spots where food has been cooked.

Any help or suggestions for getting rid of the rust would be greatly appreciated!

I had a similar problem with my Weber. But, I think it may have been from brushing too hard. I was able to call Weber and they sent me some brand new ones for free. You may want to see what type of warranty your grill has.

its not an over use proble that you have what the problem is you are being to rough on the cooking grills ... the brass brush is the worst enemy of porcelian and that is what is coating your grills ... you would never rub a brass brush on a glass window and porcelian is like glass ... every time you rub the grill you scratch and remove some of the coating and combined with the heating and cooling of the metal under the coating you end up getting cracks in the porcelian and with the damp climate you live in that water gets into the cracks and rusts the grill as well any water in the grill when you start to heat it will boil and promote cracking faster thus rust faster ... doesnt matter about cover being on or not i actually dont like them in the rain because they help to trap moisture and take forever to dry out when wet... as far as removing you cant unless you sand blast or grind off ... get new grills ... warranty is usually two or three years on grills so look into replacements ... when you get new grills i find best way to maintain and cure is preheating the bbq untill full temp then put oil on grills with paper towel and tongs and soak liberally with oil then turn down to cooking temp... i find this is best because the metal is allowed to heat expand and open the pours and except the oil right into the metal wich i find gives the best moisture barrier... final word be delicate with brushes ... hope that this helps