Blast cabinet — SBC 420

Abrasive blast cabinet for stripping paint and coatings, surface prep and engraving. Compressed air, controlled by a foot pedal, draws media from the bottom of the cabinet through the gun. The media falls back through the grate and is reused, and an attached vacuum extractor catches the dust.

Safety

• Wear a dust mask and hearing protection.

• Never blast straight at the gloves or the window. Always aim down or away.

Before you start

1. Close the door between the blast room and the chemical storage properly.

2. Check the cabinet:

   • Window film firmly attached and clear. If not, remove the old film, clean the glass and surrounding surfaces (wet wipe; white spirit for glue residue), and fit new film from the box. Wrap extra turns round the edges so it seals completely. New window and lamp covers are in a box on the shelves beside the chemical cabinet.

   • Gloves intact. A hole can be patched after unscrewing the glove; if you can't fix it, post in #blästerrummet.

   • Media not running low. If it is, post in #blästerrummet; it is ordered about 200 kg at a time.

3. Check the air cleaner filter. Vacuum the coarse filter clean or replace it.

4. Check the vacuum extractor bag. Sand is heavy, so change the bag when it is about 10 % full. Full bags go to the recycling centre (ÅVC), not into the combustible waste.

5. Empty the extractor filter (see below).

Blasting

1. Put everything you need in the cabinet: the work, tools, a small brush.

2. Close the door and lock both clamps. Don't pinch the gloves.

3. Put on hearing protection and a dust mask.

4. Switch on the extractor (green button) and the cabinet light (red button on top).

5. Press the foot pedal to blast. Adjust the airflow with the pedal, and if needed with the setting under the left side of the cabinet.

6. If the window reflects the ceiling lights, turn them off.

Air but no sand: blast downwards and release the pedal. A small heap of sand should run out of the nozzle. If it doesn't, the sand hose is blocked: cover the nozzle opening and give a few short bursts to blow it clear backwards.

After blasting

1. Wait about 60 seconds for the dust to settle before opening.

2. Clap the gloves together inside the cabinet to shake off dust.

3. Vacuum round the cabinet and the floor; some sand always escapes.

4. Empty the extractor filter, and change the bag if it is getting full.

5. Turn off the air cleaner, or check that its timer is set, before leaving.

Emptying the extractor filter

The extractor stands to the left of the cabinet, behind the door. Empty its filter before, during and after use. The gauge on its left side shows red when the filter needs emptying.

1. With the extractor running, close the valve to its right.

2. Turn the black knob on top half a turn. The extractor pulses to clean the filter.

3. After 3 minutes, turn the knob back and reopen the valve.

4. If the gauge hasn't gone back to green, the filter needs replacing.

Nozzles

Boron carbide nozzles last far longer than the old pink ceramic ones. A new nozzle is about 5 mm; replace it when it wears past 7 mm, typically after 50–100 hours. Spares are in the blast cabinet accessories box. The new nozzles are slightly loose in the gun; three turns of black gaffer tape (Clas Ohlson) makes them fit.

A worn nozzle makes blasting feel slow, because it needs more air than the compressed air system can supply. The compressor delivers about 1,380 l/min, with a few hundred litres of tank storage for short peaks. At 4 bar at the nozzle:

Heavy blasting can overheat the compressor. Take breaks on long jobs.

Links

• Verktygsstället SBC 420 product page