Tool of the week the Disc Cutter

At Block Paving Maintenance we use a Makita 12” disc cutter for the cutting of block paving, flagstones and bricks during the  cutting in on installations or repairs for driveways or patio areas. A disc cutter by another name can be known as a cut off saw or a con saw and is one of two tools used by block paving contractors to cut paving materials. The alternative to the disc cutter is the block splitter which is used solely for splitting of the same block paving, flagstones and bricks in the environment of installing, refurbishment and repairs. The disc cutter is the most versatile tool for working on driveways or block paving as they are also essential for cutting concrete, asphalt and many other similar materials, which the block splitter can’t do. However the main draw back is the enormous amounts of potentially harmful dust disc cutters can generate.

Block paving, paving slabs and kerbs all contain crystalline silica, and cutting these materials generates a fine silica dust. Exposure to this dust through inhalation can lead to potentially fatal respiratory diseases including silicosis, bronchitis, emphysema and lung cancer. Therefore it is extremely important to have adequate ppe in the way of a respiratory mask to prevent the inhalation of silica dust as well as the use of water when cutting in order to suppress any dust that produced. PPE should not only include suitable respiratory masks but eye protection and hearing protection along with suitable gloves and boots which are normally used by installers.

The average petrol disc cutters have a 60 – 100 cc unleaded two stroke petrol engine and generate between 5 and 10 hp They require regular servicing and attention to the correct two stroke petrol mix ( 4 stroke cutters are available)

Electric disc cutters can be battery operated although these don’t tend to be robust enough for regular cutting in on the average  block paving installation. Or mains powered 240 or 110 volt machines. Electric cutters are in effect large angle grinders being used specifically with a diamond blade for the cutting blocks or paving.

Petrol disc cutters have the edge over electric in that they can be used in wet conditions especially when the water needs to be self induced to suppress the dust. They are also generally more powerful than their electric counterpart.

Diamond tools work at their best when cutting wet. The introduction of water to the blade prevents it from overheating, which extends the blades life and also suppresses dust. However following any wet cutting any slurry from cutting must be washed off the surface of the block paving under repair or installation to prevent its staining.

Our current Makita disc cutter is a 64cc with 5000 rpm producing approximately 6.5 horse power. When cutting block paving for an installation or repair it gives a depth of cut of around 100mm The size of the blade is important in cutting as it gives the depth of cut with larger the diameter giving the greater depth. Diamond tipped blades compared to an abrasive blade on an angle grinder wear better offering a longer working life especially if used when cutting wet. An abrasive blade wears when in use gradually reducing the blade diameter and thus reducing the cutting depth. A diamond tipped blade doesn’t wear so quickly and therefore offers a more constant depth of cut, a benefit for the paving installer.