When we blast, we must consider the coating being removed. If the coating is harder than the substrate, the substrate will be damaged or tunneled under. For example, think of tough epoxy paint on soft cedar siding. The cedar will get scarred and damaged, and the paint will still be intact. In this case, no media would have done the job. In fact, the epoxy needs to be softened, or removed through other techniques. Using the right equipment, learning how to blast, and understanding the requirements of the surface are the keys to coatings removal. Just taking the coating off without giving care to the surface is a fatal mistake, and will result in damages and liability.
Here is a quick look at some of the blasting media available on the market today:
Silica Sand - The grandfather of blasting medias, silica is being banned throughout the world (Silicosis) and this product, while cheap and excellent at rust and heavy metal cleaning, has a reputation of being the destroyer of products.
Soda/Sodium Bicarbonate - When used in an efficient machine, this media delivers excellent results for degreasing, smoke and fire restoration (odor eating) and mold removal. It is the slowest of the medias for coatings removal, leaving a film that must be removed prior to coating.
Kierserite and Super K - these medias are harder than soda and thus faster. They do not leave a caustic film and are very effective at removing paints. Applications can include automotive coating (paint) removal, and removing paint from stone.
Corncob - Yes, corncob, a non-nutritional product that works excellent in wood restoration situations. The surface can be readily stained or painted, as the cob is a natural fiber product similar to the wood.
Crushed Glass- This replacement for sand is fast, clean and comes in various sizes, providing a consistent profile and running extremely smooth. This is an excellent choice for rust removal, heavy paint, heavy metal, and profiling.