Removing paint from brick can often be a process that requires a difficult combination of aggressiveness and delicateness. Brick (and concrete would apply as well) is a porous surface that does an excellent job of holding onto paint and coatings. The paint can be trapped in all the nooks and crannies of the surface making it very difficult to remove all the paint. As brick can be a decorative surface, it is important to not use a process that is too aggressive as it can strip away the brick material. This leads to an uneven and damaged surface that is unappealing.
Walnut shell grit offers the perfect balance of aggressiveness and safety on the brick surface. Using a finer grade of walnut shell grit will strip the paint from all the ‘hidden’ areas on the brick surface but will not blast away the brick itself. In addition, because walnut shell is an organic material, the process is environmentally friendly and the clean up is easy.