How to achieve an optimum end result
To ensure you achieve the optimum result you are aiming for when working on aluminium – whether cutting, grinding or polishing – the factors below need to be considered at all times:
- Use cutting and grinding discs with specialised bonding that prevent the disc from clogging up.
- Always use flap discs with a suitable, specialised coating for your task.
Hazards when working on aluminium
When you cut, grind or polish aluminium, aluminium dust is always created. This dust is itself easily ignited and also reacts with moisture to form highly flammable gases. This creates the risk of a dangerous grinding dust explosion.
Breathing in aluminium dust can also cause aluminosis (also known as ‘aluminium lung’). If the dust then passes from the bloodstream into the brain, this also increases the risk of Alzheimer’s disease.
Cutting and trimming aluminium
- An extra-thin cutting disc with special fillers prevents the disc from clogging. This maximises your cutting performance, even on low-power machines.
- If you are cutting aluminium with an electric angle grinder, you can reduce dust generation by 50% if you use an extra-thin aluminium cutting disc.
- Always clean the angle grinder after each work session. Aluminium dust is very fine: even with an extraction system, dust can still build up in the angle grinder and cause irreparable damage. Air grinders are less susceptible in this situation.
Bevelling aluminium – preparing for a weld
- Use a grinding disc, flap disc or fibre disc here with specialised bonding that prevent the disc from clogging, and therefore guarantee a continuous and highly efficient grinding operation.
- Discs marked with the ‘ALU’ symbol achieve a high level of stock removal combined with a cool cut. This results in fewer tarnish colours. The discs are an excellent choice whether you need to work on bronze, brass, bearing metal or aluminium-magnesium alloys.
Deburring aluminium – using a carbide burr to prep and finish welding seams
- For working on aluminium, you should choose specialised tungsten carbide burrs with fewer but more deeply-cut teeth, a positive rake angle and specially ground facets.
- When you need to work on aluminium, the optimum speed is 700 to 900 m/min.
Polishing aluminium
- To achieve an optimum surface finish, the workpiece should neither exhibit deep scratches nor any inclusions. Ideally, the aluminium will have been prepared with a grit size of 60 or higher before polishing.
- The last few fine scores can then be removed with combination tools featuring non-woven abrasives and abrasive cloth. Work with reduced speeds in this step and the next steps.
- Compact non-woven tools are recommended for further smoothing of the surfaces.
- The first step here is pre-polishing, with a harder felt or harder polishing ring made from cloth felt and an appropriate paste.
- You achieve the final, mirror finish with tools made from a softer felt or soft polishing rings made from cloth felt and the appropriate paste.
- Always use a separate tool for your pre-polishing and high-gloss polishing tasks.