I've been refinishing a fireplace/mantel, which has included stripping layers of paint off the brick fireplace. After months of chemical applications, most of the paint is off, but there are still some stubborn remnants that just aren't coming out - they seem to have soaked into the brick, and make the fireplace look like a mottled mess. In a fit of frustration I decided to use some sandpaper to sand out the paint, which worked wonderfully well, but seems to have left me with a new problem - skinless bricks. I didn't know bricks had skins (hard outer shells apparently produced in the firing process) until I sandpapered some of them away. Is there any way out of this dilemma? Is there some sealer I can use to put a hard coating (and some sheen) back onto the bricks? Or am I fated to painting over the whole thing. I'd be extremely grateful for any advice - I'm feeling a bit desperate at this point!

My guess would be try a laquer or a polyurathane or a concrete sealer.