D.S. Slocum

Founder of the Slippery Rock Gazette

Did you know that an electric tool’s life is measured in hours?

Electric tools are designed and manufactured to meet certain criteria, one of which is a life expectancy. Generally speaking, a quality electric hand tool is designed for an average of some 400 to 500 hours of use. There are, however, all kinds of things that can affect how long a tool lasts. Operator abuse is the number one culprit affecting longevity, or using the wrong tool, the wrong RPMs, or too light of a tool for the job. Tool failure can occur after continuous operation with no time allowed for the tool to cool and, more commonly, from lack of proper maintenance.

Let’s go back and examine the first statement. The life expectancy of a quality electric tool with proper maintenance is 400 to 500 hours. Six hours of use per day multiplied by 5 days in the work week equals 30 hours of use per week. Figure thirty hours of use divided into the normal life expectancy of the tool– we will use 450 hours in this example, equals 15 straight weeks of production that can be expected from a single electric tool. You read me correctly. Every four or five months you will need to purchase a new tool. In industry use (and the stone industry is no exception), an electric hand tool is an expendable resource, just like diamond pads or sandpaper.

That’s not something most fabricators want to hear. Can a better tool be manufactured? Maybe. The more important question is how can you squeeze the maximum life out of an electric tool? And the answer is simple: Disciplined maintenance. What follows is brief list of suggestions that should help to maximize the return on your investment.

Three Simple Rules for Maximum Tool Life

  1. Clean the motor daily by blowing compressed air through the vents of the tool. (see diagram) If you don’t own a compressor, now is the time to buy one. For the job site, cans of compressed air may be used as a substitute. Any office supply or computer supply store carries  “canned air,” but they generally don’t supply the pressure needed for a good cleaning.
  2. Change the carbon brushes on your tool on a regular basis– every 50 to 60 hours of use. Don’t wait for them to fail. Some manufacturers supply extra brushes with a new tool, and Braxton-Bragg offers OEM replacement brushes to fit the most popular tool lines that they distribute.
  3. Re-pack the head of the tool every 100 hours with a quality lubricant.

Aim compressed air (red arrows) at the tool vents to dislodge and remove dust and dried slurry.

Good quality tools are supplied with an overload or cutoff switch. This is to protect the tool from operator abuse. When the overload switch is tripped, it is a warning.

It generally means that the tool is running too hot. Wait five to ten minutes , allowing time for the tool to cool, then resume work. If the switch trips again SOMETHING IS WRONG. Stop working with that tool until proper corrective measures are taking. NEVER bypass the overload switch. It’s simply a Bad Idea.

One final comment: in the stone industry, we have developed an electric tool that is unique to this industry–the center water feed grinder or polisher. This type of tool creates a special challenge to the user. It is vital to the life of this tool (and more importantly, to the life of the operator) that the tool is held in such a way as to prevent water from entering it. 

Special precautions need to be taken in the use and maintenance of center water feed tools. First, always work with a GFCI (ground fault interrupter). Second, it is imperative that this type if tool be blown out at the end of each day. The use of copious amounts of compressed air both cleans and dries the inside of the tool, extending the life of the tool and also protecting the operator from electrical shock.