Lime mortar on the surface of used clay bricks from demolition

Used bricks from demolition have remains of lime mortar on their surface. This mortar remains cannot be removed from the brick surface without special chemical treatments or sandblasting. But that is not the point! The charm and what is specific to used bricks is the rustic surface covered with white mortar remnants. chemical cleaning of demolition bricks is expensive and sandblasting damages the brick surface and reduces resistance to frost.