Wet sandblasting: the right way to sandblast using pressure washers

Wet sandblasting removes tough dirt from durable surfaces. We show you how to achieve optimum results.

A man in front of a garage wet sandblasting using the STIHL RE 130 PLUS high-pressure washer

Overview: Sandblasting using a pressure washer

  • Sandblasting using pressure washers, also known as wet sandblasting, is suitable for cleaning durable surfaces such as metal, stone and concrete.

  • You can upgrade any pressure washer with a STIHL wet sandblasting kit.

  • Wet sandblasting works best with special sand granulate. The use of quartz sand is prohibited by law and poses a health risk.

  • Removed dirt and used blasting granulate should be collected and disposed of properly after use.

 

Areas of use: suggested applications

Wet sandblasting works a little like sandpaper. High-pressure sandblasting removes rust and dirt from durable surfaces such as metal, stone and concrete. While grinding machines are great for cleaning flat surfaces, wet blasting with a high-pressure washer is best for uneven surfaces.

So ideal areas of application for wet sandblasting include:

  • Corrugated metal fences

  • Dirty masonry

  • Small, durable metal parts

Items required for wet sandblasting

STIHL RE 130 PLUS high-pressure cleaner and SB 90 blasting granulate for wet blasting in front of a garage

There are  three essential components for wet sandblasting: a pressure washer, a wet sandblasting attachment, and appropriate sand granulate such as STIHL SB 90 blasting granulate. 

Instructions: How wet sandblasting works

Before you start the actual wet sandblasting, you should prepare the surface for cleaning.

For example, if you want to remove rust from a metal fence, first disassemble it to its individual elements. Spread out a tarpaulin to collect the removed rust and blasting granulate, and dispose of them properly after the work has been completed. This preparation also ensures that you can maintain an optimum distance at all times and that the blasting granulate only hits the surface to be cleaned; delicate plants in the flowerbed behind the fence remain protected.

A man in front of a hedge wearing protective gloves holds the STIHL RE 130 PLUS high-pressure cleaner for wet blasting

Preparing the pressure washer

Before starting up your pressure washer, make it ready for use as usual. Then fit the wet sandblasting attachment to it; attach it directly to the spray lance in place of the nozzle. Insert the other end of the wet sand-blasting attachment into a bucket containing the appropriate blasting granulate. The optimum quantity of granulate is automatically conveyed via the hose.

A man wearing protective gloves prepares STIHL SB 90 blasting granulate for wet blasting

Only use suitable and non-hazardous sand granules for wet sandblasting. Avoid sandblasting with quartz sand in particular. Sandblasting with quartz sand is  prohibited in many countries as even with breathing protection measures in place, its fine crystals can enter the lungs when used with pressure washers, and so it poses a health risk.  STIHL SB 90 blasting granulate is made of iron-containing aluminosilicate glass and is silicone-free.

Video: The right technique for wet sandblasting

When sandblasting the effective area is a circle of about three centimetres in diameter. With this in mind, move the jet slowly over the surface to be cleaned, as if in slow motion, so that the mixture of water and blasting granulate can effectively remove the dirt. For stubborn dirt, carefully increase the pressure or repeat the process.

After use, empty the granulate hose.

Do not switch off your high-pressure cleaner immediately after work has been completed. First remove the end of the hose from the granulate bucket and then press and hold the spray gun until the granulate has completely drained out of the hose. The wet sandblasting set has now been emptied and is ready for storage.

Finally, dispose of the collected dirt and the blasting granulate properly.