A wall chaser is a power tool used to chase or cut channels in masonry walls to accommodate electrical wiring or pipes. This tool is typically a hand operated units similar in design to an angle grinder which make the cuts using abrasive discs or masonry blades. Most wall chasers contain drive heads which make provision for mounting either one or two discs or blades at the same time. Dual blades allows for a channel of adequate width to be cut in a single pass. As masonry cutting generates large quantities of dust, a wall chaser typically includes a dust extraction system fitting.
Electrical wiring and piping is generally installed after the erection of the buildings walls. Routing the wiring or piping requires a groove or chase to be cut into the wall surface to accommodate them. Before the days of power tools, the chase was cut with a chasing chisel and a hammer. Although this method is still used and is handy in tight spots or for short chases, it is a laborious and time consuming process. Wall chasing machines make short, if not noisy and dusty, work of long wiring and piping chases in the hardest of masonry.
Modern wall chaser hand tools are similar in design to a angle grinder except the blades are vertically orientated. Abrasive discs such as those used on an angle grinder or special masonry blades are utilized to execute the cut. The drive heads of wall chasers generally make provision for mounting either one or two blades or discs at a time. The dual blade configuration is generally used where full width cuts are required for mounting water pipes and electrical conduit. A fairly large range of different wall chaser models are available with average power ratings running between 1,200 watts and 2,000 watts and with blade sizes between 6 and 9 inches (150–230 mm).
Cutting masonry generates large amounts of fine dust. As a result, most wall chasers will feature either a dust bag or fitting for connection to a dust extraction system. These systems should always be used in conjunction with a dust mask or respirator because the dust generated can be truly impressive.
The wall chaser is a powerful tool driving a pair of extremely sharp blades; it is wise for operators to fully acquaint themselves with the manufacturer's operational instructions and safety measures prior to firing up the machine. Personal protective equipment is also a must; eye and hand protection should always be worn. It is also important to use a suitable scanner to check for the presence of other piping and wiring in the wall before chasing.