A compressor draws in ambient air along with its moisture. Compressing it concentrates that water: the hot air leaving the compressor is loaded with it, and it condenses as soon as the air cools in the receiver, the hoses and the machine. For most tools, a few drops go unnoticed. In dry soft blasting, they are enough to ruin a day's work.
What water does
- The abrasive clumps. Fine, damp abrasive forms lumps in the hopper and no longer flows evenly.
- The metering valve clogs. The abrasive flow becomes irregular, blasting comes in bursts, and the job has to stop for dismantling and cleaning.
- The surface gets marked. The finish becomes uneven, with areas stripped too much or not enough.
- Rust comes back on steel. On bare metal, moisture blasted with the abrasive brings back a thin film of rust before painting even starts.
- Abrasive is wasted. Damp abrasive recycles poorly and ends up in the skip sooner.
The problem gets worse in summer, when ambient air is hot and humid, and when the compressor runs for long periods without a break, which is exactly the case in soft blasting.
The fix: dry and filter at the compressor outlet
Three items, in this order:
- The receiver and its drain. Part of the water condenses in the receiver. It must be drained regularly, ideally with an automatic drain.
- The refrigerated dryer. It cools the air to condense the moisture, then removes it. It is the essential piece of equipment for dry soft blasting.
- Filtration. It traps particles and oil aerosols before the blasting machine.
To compare dryer types, read our article which air dryer to choose. Our flow and pressure converter helps you check that the dryer is sized for the compressor's flow.
Why a 4-in-1 compressor makes it simple
On a 4-in-1 compressor, the receiver, refrigerated dryer and filtration are already fitted and sized for the compressor. There is nothing to assemble or calculate: the air reaches the blasting machine dry from the first start.
- The K 150 delivers 2.2 m³/min at 8 bar, with a 340 L receiver, refrigerated dryer and filtration built in.
- The K 110 delivers 1.7 m³/min at 8 bar, in the same configuration.
If you already have a receiver and dryer, the S 150 delivers the same flow as the K 150, without the built-in equipment.
What about wet blasting?
In wet blasting, water is added to the mix on purpose to keep dust down. Dry air still matters: it protects the compressor, the hoses and the machine, and it is the machine that meters the water, not the air network.
To choose the compressor for your machine's flow, see our article which compressor for soft blasting.
For your trade: Compressor for soft blasting, Compressor for body shops, Compressor for metalwork and fabrication shops.