Shotblasting Preparation
The method of shotblasting involves steel abrasive (shot) being propelled at high velocity onto a rotating wheel within the machine body, and then down onto the designated surface to produce the desired profile.
You would select shotblasting to:
- Texture and clean concrete, asphalt or tiled surfaces
- Remove paints and sealants
- Create adhesion for the application of a wide range of surface finishes
- Key bridge decks and roads for surface dressing and waterproof systems
- Prepare steel (Commercial and Swedish Standard SA2 ½)
The type and size of the machine selected will determine production rates achievable and degree of profiling required for the specified material to be applied.
The Preparation Group’s shotblasting machine model numbers refer to the width of the blast pattern created by the machine i.e. 215mm, 265mm, 400mm and 558mm.
Surfaces suitable for shotblasting include:
- Any hard composition surface that does not exhibit multiple layers of materials or contaminants. i.e. Concrete, Steel, Terrazzo.
- Asphalt surfaces – Note:- with all bitumous compounds, heat and size of the area must be considered.
An infinite range of profiles are achievable via this process, determined by the grade or size of shot selected and the speed at which the machine is propelled. Note:- large machines are manufactured to use large grade shot.
The debris is collected in the “collector” – a vacuum unit for disposal, and the shot reclaimed for continued use.
Examples:
- Removal of laitence on power floated concrete
- Removal of coating on steel
Key considerations:
Due to the nature of the operation, Shotblasting will produce a lining effect commonly know as tramlining. This can be minimised with operator experience.
Shotblasting will highlight surface defects in the surface being prepared. This is particularly important to note when applying to old concrete.
- Soft composition screeds
- Sticky/bitumous materials
- Materials in excess of ½ mm thickness
Shotblasting cannot be applied to wet or damp conditions.
For optimum results, Shotblasting requires a smooth even surface.
Steel abrasive (Shot) will escape from the machine when operating on uneven surfaces.
