TUFF COATINGS AUSTRALIA Abrasive Blasting

What is Abrasive Blasting

Abrasive blasting is when garnet, grit or steel shot is shot onto a metal surface using compressed air.
The impact of the high speed particles cut away mill scale, rust or contaminants leaving a clean surface.
This leaves small indentations and these are referred to as the ‘key or surface profile’.

TUFF Coatings use a premium grade garnet to achieve the best quality blast results for our clients. Known for its natural hardness, durability and abrasive characteristics, GMA Premium Garnet meets all occupational health and safety requirements.
We work closely with our supplier to remain up to date with technology and techniques to deliver cost effective, contamination free substrates.

Different Classes of Blasting

There are four classes of abrasive blasting and these refer to the cleanliness, contaminant, and colour.

• Sa 1 – Light blast cleaning
• Sa 2 – Medium blast cleaning
• Sa 2.1/2 – ‘Near White’ blast cleaning
• Sa 3 – ‘White Metal’ blast cleaning

A full break down of these standards can be found in AS 1627 – Surface Preparation Standard and our trained staff can make recommendations on a suitable class for your project.

Surface Contaminants

When Tuff Coatings prepare steel surfaces for a protective coating system, it is critical we remove all contamination. Common forms of contaminants are mill scale, rust and oils, grease fat and perspiration and old protective coating systems.

• Mill scale, found on new steel, consists of distinct layers of iron oxides and is formed during the manufacturing of steel. It is not firmly bonded and will lift over time causing the paint to flake and corrosion to occur.
• Iron Oxide (rust) is formed when steel surfaces are exposed to oxygen and moisture for long periods. Given sufficient time, oxygen and water on an iron mass will eventually convert entirely to rust and disintegrate.
• Oils, grease, fat and perspiration must be removed using a solvent degreaser.
• Coating systems fail if applied incorrectly. When recoating a structure or piece of equipment to has been heavily effected by rust or other contaminates it is important to remove the system completely, visually inspect the surface, repair and repeat the abrasive blasting process.

Surface Preparation during and after Manufacturing

Coating systems are usually the last step in the manufacturing stage and a quality coating finish will add value to your structure, equipment or DIY project.
To assist us in achieving a flawless coatings system defects, welds, burrs, sharp edges and lamination should be ground and filled before being abrasive blasted. Failure to prepare and remove harmful deposits will result in the breakdown of the protective coating system.

How you can help us achieve a flawless finish:

• Remove weld splatter by grinding
• Grind all welds and high points smooth
• Remove any surface contaminants