Sandblasting is an intense, high-powered process that removes paint and/or rust from various surfaces. It can be compared to sandpapering, but it is a potent version of that task. The two general sandblasting methods are wet sandblasting and dry sandblasting. Those methods are identical except that the former includes the use of water. Where they differ is their intended target.
All sandblasters want to clean and strip a surface. Their use of a wet or dry blaster is identical in the sense that each tool uses a powerful and potentially dangerous force to destroy and strip old paint or other impurities rapidly from a surface. Sandblasting very quickly and cleanly does what manual sandpapering can take days to accomplish.
By far, wet blasting is the most common means of stripping surfaces. In general, the wet blasting machine uses a high-powered stream of water that is mixed with abrasives. The abrasives include glass beads, different kinds of sand or even baking powder. Wet blasting is most commonly used to strip old paint or remove graffiti. The abrasives make the surface very rough. That factor is deliberate because the rough surface is both clean and able to absorb paint more readily than a smooth surface.
City or country authorities almost always need to give special permission for dry blasting. Dry blasting is identical to wet blasting except that it includes the use of highly pressurized air rather than water. The dry blasting process is more dangerous then wet blasting because it is similar to a very fine, continuous shotgun blast. It is used most often on metal surfaces to remove rust. One of the problems with dry blasting is the possibility of inhaling the tiny shards of glass or steel filaments used as abrasives. Only professional blasters use such equipment. In some areas, a dry blasting project requires the permission of the city or county as well as permission, or a variance, from residents living near the proposed dry blasting project's site. Some blasting firms argue a project's case to the neighbors in return for extra money from their employer for the project.
Besides using or not using water, another difference between the two methods deals with surface material. Metal objects such as oil tankers require dry blasting. Also, amateurs should not use dry blasting equipment. Wet blasting is safer and easier, and non-professionals might be able to do it safely and effectively. Its big advantage is that it does not create the huge and potentially dangerous dust clouds that result from dry sandblasting.