What is Sandblasting? Although first patented in 1870 by Benjamin Chew Tilghman, sandblasting such as we see today was a process largely developed and refined by the US Navy for use on steel, which they obviously had an abundance of. During it’s early years, sandblasting was largely a mechanical process used primarily by it’s patent holder for sharpening and grinding tools. Today’s process of sandblasting is much refined from it’s original beginnings and is now used in all manner of ways. It is often called other names such as “bead blasting”, “shot blasting”, “abrasive blasting” and others. Most typical sandblasting we see today is a process using compressed air to move sand (or other abrasives) through reinforced rubber hoses and nozzles at extreme velocities (about the speed of a 357 Magnum pistol bullet) to abrade various types of substrate to clean, etch, remove, or burnish various types of coatings, rust, mill scale, and other contaminates in preparation for applications of paint, coatings, stain, other treatments or left in its natural state.
All types of substrates can be sandblasted. Every type of metal, wood, concrete, glass, etc., has been sandblasted. Many times sandblasting is both the beginning and ending process, other times sandblasting is an integral part of a complex process of coatings or other processes.
From sand, to glass, to steel shot, and even organic materials, there are literally hundreds of types of media that can be used for sandblasting. When certain media types are used, such as glass bead, steel shot, sodium bicarbonate (baking soda), or others; sandblasting will often times become “renamed” to better reflect the media type being used — Such as, “bead blasting”, “shot blasting”, “soda blasting”, etc. Still, sandblasting is the original terminology used behind all of these when talking about propelling abrasives under air pressure through hoses and nozzles.
The original method developed which uses a mechanical action rather then compressed air to move abrasives, is still in use today. Most of these use a process of spinning a wheel which catches and flings abrasives towards the surfaces to be abraded. The original version of this type of process was call a “Wheelabrator” and was the process first used by Benjamin Tilghman. Today, “Wheelabrator” type machines are still used in many steel plants to abrade new and rusted steel to remove both existing rust and mill scale, this process is quite successful and quick as it is often used in an automated process where either steel shot or crushed steel shot is used for both its quickness in cleaning and recyclable properties. Concrete flooring is also effectively cleaned and etched using mechanical “wheelabrator” type blasters. This type of “blasting” equipment will usually use some type of steel shot so that it can be magnetically picked up during the process, while dust and other debris are vacuumed up — All at the same time and by the same equipment.
Over the years, a few recognized organizations have evolved to help determine more exactly what specifications can and should be used when speaking about or asking for suitable sandblast specifications and requirements. SSPC (The Society for Protective Coatings), NACE (National Association of Corrosion Engineers), and others have been instrumental in both providing these specifications as well as developing testing standards and workable terminology that end users, architects and sandblasting contractors can understand and follow. We have a Sandblast Color Chart of “workalike” SSPC Sandblasting Specifications on this website which may help you visually see differences between SSPC-SP-7 (Bruss-Off Blast Finish), SSPC-SP-6 (Commercial Blast Finish), SSPC-SP-10 (Near-White Metal Blast Finish) and SSPC-SP-5 (White Metal Blast Finish).
Sandblasting is much of the time the only process that is suitable for a particular task. It is both fast, effective and capable where other methods may not perform suitably. It is also, without proper safeguards and training, quite dangerous to both operators and property. Never presume it is something you can just “try” for yourself. There are many ways to use sandblasting safely and effectively, and even more ways to do damage and cause harm, pain and suffering. Only trained, professional operators and helpers should operate any sandblasting equipment.