Bricks sometimes get holes in their surface, either from normal wear or from drilling and boring. Leaving these holes may result in cracks caused by freezing water that has entered through the surface of the brick. These holes need not be permanent since there is a tried-and-true way to repair them. You can repair holes found in bricks in 4 to 8 hours, depending on the size and scope of the project.
Mix the mortar in a 5-gallon bucket. Since you may be repairing a small amount of holes, mix one part sand to two parts mortar powder. This will cause the mortar to be sticky, which will make it harder and more durable. Add one shovel of sand to two shovels of mortar if you are using a shovel or one coffee can of sand to two coffee cans of mortar powder if you are using a coffee can. Add one part water and mix with a paddle bit and drill.The consistency of the mixture should resemble a thick pancake batter. If not, then add more of each ingredient until you have achieved the desired consistency.
Spray water into the hole in the brick with a misting bottle. Adjust the stream so that it is straight so that it will clean out the hole. The water will moisten the hole so that the mortar will stick.
Press a small amount of mortar into the hole using a pointing trowel. Continue to fill the hole until the mortar mounds up on the surface of the brick. Do not cut the wet mortar off of the surface as this will cause mortar smears. Wait until the mortar hardens, but is still wet and then cut it even with the surface of the brick.
Seal the mortar patch with concrete sealer. This will prevent the mortar from breaking down and flaking away from the hole. Use the misting bottle to apply concrete sealer. Apply the sealer liberally and allow 30 minutes drying time between coats. You can apply up to three coats of the sealer.