Add glaze paint to the fireplace bricks to provide a glossy finish.
Preparation
Clean fireplace bricks are essential to the painting and glazing process. If dust is the only cleanliness issue, simply use a vacuum attachment to remove the dust. A light amount of soot on the bricks is usually not a problem if it won’t come off with a little soap and water. For stains that will not come off easily, use TSP, trisodium phosphate, to clean the surface. This solution needs a good rinsing before you can paint the bricks.
Suitable Paints and Glazes
In addition to adhering well to fireplace bricks, water-based latex paints are suitable for this kind of project due to having less of an odor from the paint fumes. Oil-based paints have a thicker consistency, take longer to apply and dry and produce strong odors. Finish the newly painted bricks with clear glaze paint. While glazes come in different colors, the clear glaze will provide a smooth finish and maintain the new paint color. In addition, glaze provides added sheen to the bricks and helps protect the paint.
Applications
Prime the fireplace bricks with acrylic universal primer, which is suited to work on most surfaces. Primer helps the paint adhere to the porous brick surface. Use rollers to apply the primer and then the paint. A paintbrush is best to paint the mortar in between and along the edges of the bricks. Start from the top of the bricks and work your way down for an even application of paint. Apply more than one coat of paint as desired; additional coats will darken the paint color. Add a thin layer of glaze with a paintbrush over the newly painted fireplace bricks after the paint dries.
Considerations
If you plant to paint the bricks a dark color, have the paint store add about half the color to your primer. Wear protective clothing and a facemask when you apply the primer, paint and glaze to protect yourself. Always properly ventilate the room when you use these products.