Wet blasting, wet sandblasting, or vapor blasting, it’s all the same. It’s the process of using sand (or other abrasive substances) mixed with water, being blasted at high speeds and pressure towards a surface. This mixture will remove contaminants from that surface.
This is done by attaching a kit to your pressure washer and sticking the kits prob into a bucket filled with an abrasive medium. When the pressure washer is activated, the movement of the water draws the sand up the probe line and mixes with the water.
It’s then propelled at the surface you wish to remove contaminants from such as rust, or for finishing a surface.