So I have a Lang 36" hybrid, and I've noticed over the last year rust has started building up around the outside of the firebox. It wasn't bad, so I took a grinder and knocked it off, and I've put about 4 separate coats of stove paint over the areas that were affected. Is that enough, or should I continue with a couple more coats? I'm not sure how many coats you guys typically apply. Thanks!