Any way to get thick paint off a fireplace without wrecking it?

First work out what the surface is. Painted stone, brick, and mortar behave very differently from a metal facing, and the paint can make the material hard to identify. If it is masonry, try a remover specifically labeled for masonry on a small, hidden area and follow the directions. A test patch can show whether the paint lifts cleanly or leaves color in the pores.

Even when the paint comes off, a rough surface may not look fully natural again. Paint can linger in pits and mortar, and aggressive scraping or sanding can scar the surface. If the test result is poor, get an opinion from a stone restoration contractor before doing the whole fireplace.

If it turns out to be metal, don’t treat it like stone. Identify the metal and use a paint remover that’s suitable for that surface, testing a tucked-away spot first. Heavy sanding can leave scratches, and an unknown coating may be doing more than just changing the color.

Also check whether this is a decorative surround or a surface exposed to fire. Products used there need to be appropriate for the heat, and any remover needs to be fully cleaned off before the fireplace is used again.

I’d be wary of pressure washing or grinding as a first move, especially inside the house. Water can make a big mess indoors, and harsh abrasion may remove some of the original surface along with the paint.

For a tall or irregular fireplace, ask a restoration specialist to assess a test area and give you a realistic idea of the finish and cost. Sometimes the paint has soaked in enough that a clean, untouched-looking result just isn’t achievable.