 I don't know if you've seen it, John, but there's plenty of products out there that you can mop on there. And it's fairly simple. You pressure wash it, clean it, get rid of anything that's loose. You can fill it with mortar if you have big chunks out, or you could just buy the sealer, the mastic-type sealer. It's very thick. Basically, you just paint it on there in a couple of coats of that, and you've now sealed the crown of your chimney.