I need to paint a fireplace. I looked it up and the site I saw recommended that I use masonry primer because there might be moisture issues otherwise, then paint the fireplace with exterior paint. I went to Lowe's and they didn't carry masonry primer, but told me to buy bonding primer then paint with interior paint. Anyhow, I don't want to have moisture problems and the guys at the hardware store don't seem to know what I'm talking about but then I asked the guy that installed our insert and he said that he's seen moisture problems without masonry paint but didn't really know what I should use but said I should seal the outside of the chimney with some sort of clear coat later when I have the time. Any suggestions? It's a stone fireplace that's already been painted with possibly one cote of masonry primer, but would likely need another primer at this point. Thanks