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Charles Lewton Brain

Grinding Wheel Safety Thoughts

by Charles Lewton-Brain - © Brain Press Publications
Besides the safety instructions that you get from a tool manufacturer in the tool manual it may be necessary for you to write your own sets of rules up to keep you out of trouble. This is especially important with employees. What follows is an example of thinking about what can go wrong with a tool. The tool used as an example is a mounted grinder. You can do the same sort of rule compilation with all the tools in your shop. See the "General Safety Rules for Tools" article as a starting point, then each tool will have certain idiosyncrasies which need to be noted. Think of it as "What advice would I give to someone to keep them out ot trouble on this machine?"

Note: These are only some points regarding this issue; this description is likely riddled with errors and omissions and is a guideline only to certain types of hazards. Other hazards not mentioned here exist. Read your owners manual carefully for the tool and equipment you are using.

Instructions: Read each sentence to yourself and preferably out loud to another person. Carefully discuss and come to agreement with the other person on the meaning of the sentence. Add any precautions or important information we have missed to this text: just write it in on the page along with the information we are reporting here.

Some of the hazards of grinding
Flying razor-sharp chunks into your eyeballs and skin, fire (from sparks, electrical short circuits, flammable materials leaping into flame), detonating grinding wheels, objects kicking back (and through you), burns, gouges in your hands, sucked into the machine by your jewelry or clothing, electrocution, dusts and particulate, ergonomic damage and loss of hearing (and here are probably lots more hazards I forgot).

General Precautions

  • Keep a regular maintenance/inspection cycle and keep a log in your shop tool binder.
  • Read the manual carefully-spend a minimum of 1/2 hour on it. And review it once in a while. Follow its instructions carefully when changing parts or accessories.
  • Wear adequate eye and hearing protection. Wear hair up and avoid loose clothing or jewelry.
  • Do not talk to anyone while using this machine.
  • Do not have any distractions while grinding.
  • Keep this tool in its own small area, free of clutter, preferably with at least low walls around the area to isolate the tool and debris from it.
  • Have good housekeeping and clean the area around the tool after every use.
  • ake sure local ventilation is appropriate for the tool
  • Have good lighting on the working area of the wheel, a mounted desk lamp or one on each side is good (illumination from two sides eliminates shadows)
  • Always have the machine properly mounted and screwed securely in place onto a sturdy work surface.
  • Turn off the machine when not in use.
  • No children in the workshop.

flying particles, sparks These can embed in your eyes and skin, at the time of grinding or later. Flying particles can also be sparks which can set you, your clothing, your shop on fire

  • Wear eye protection
  • Always keep the eye shield on the grinder in place and properly adjusted.
  • Wear a face shield as well as safety glasses, keep the face shield close to the chest.
  • Fire proof clothing/apron.
  • Local fire proof exhaust for particles.
  • Grinding area easy to clean and isolated from other work areas.
  • Keep all flammable materials, paper, cloth, solvents, potential fuels away from the grinding area.
  • Do not grind wood or other flammable materials on the same wheel used for metals.
  • Clean up particles using hand broom/vacuum (never with your hands) after every use of the machine-make a habit of it.

wheel disintegration A cracked grinding wheel can fly apart suddenly and chunks can, literally rocket right through your body. A student of mine saw a piece of grinding wheel go right through someone's thigh and out the other side in a machine shop they were working in.

  • Always treat grinding wheels gently, never hit them with anything.
  • Always use a wheel guard.
  • If you have dropped a wheel do not use it or mount it on the machine. Throw it away.
  • Do not use a wheel that may be damaged.
  • When starting up a grinder always stand safely to one side until the wheel has reached speed and run for some seconds at speed. If a grinding wheel is going to fly apart it often does so during the wind up phase.
  • Wear your protective gear.
  • Use the right grinding wheel for the job, properly rated for the motor speed and the correct size.
  • Ring test a grinding wheel before mounting it or changing it.
  • Inspect the grinding wheels carefully on a regular basis.
  • Grind evenly across the face, avoid creating ruts in the wheel.
  • Do not use the side of a grinding wheel, just the face. Side pressure can cause a wheel to crack.
  • Do not grind too hard, do not try and take off too much material too fast, use the right tool for the right job.
  • I recommend only grinding steel on the wheel. Use a belt sander for non-ferrous metals.
  • A wheel "loaded" with metal residues cannot grind properly.
  • Do not grind when you have turned the motor off and the wheel is spinning down to a stop.
  • Dress the wheel with a wheel dressing tool if required to keep a wheel flat. Wheels with chips, flat spots, gouges and glazed areas should be dressed. Bad spots like that can make grinding more hazardous and inefficient, reduce accuracy, and damage the work surface by burning or gouging it. Dressing your wheel helps keep it balanced, which is important for safety.

metal trapped in between tool rest and wheel If a piece being ground is trapped in the guard it can cause a wheel to shatter explosively, be flung out suddenly piercing you or others like a spear or flip up trapping your fingers against the wheel thus causing severe damage.

  • Always keep the tool rest the correct distance from the wheel, usually 1/16th of an inch (1.5 mm). As the wheel is ground down the tool rest needs to be reset.
  • Be especially careful when grinding edges, corners, ragged joins and so on.
  • Check the tool rest for tightness and position EVERY TIME you use the grinder-make a habit of it.
  • Always brace your holding hand on the tool rest so the object being ground is securely held and cannot get caught in the gap at the tool rest or bounce back at you.
  • Do not use pliers (or anything in which the work being ground can slip) to hold an object being ground.
  • Never put the object being ground close to the gap between the wheel and the tool rest.

clothing trapped in wheel clothing, hair, jewelry can be caught on the wheel and cause severe injury.

  • Do not wear gloves while grinding (or using a polishing machine)
  • Tie hair back, better is to wear a visorless cap as well
  • do not wear loose clothing, tie, jewelry
  • Roll your sleeves up
  • Never bring your head close to the moving wheel

Kickback
If a workpiece being ground is caught on the wheel it can suddenly jerk towards you in the hand

  • Do not hold a piece of metal so that it can puncture your palm if it kicks back and out.
  • Hold the workpiece very securely bracing the hands on the tool rest
  • Be aware of the potential for kickback.
  • Touch the workpiece repeatedly to the wheel, take off metal a bit at a time.
  • Draw the workpiece smoothly across the front of the wheel.
  • Never put the object being ground close to the gap between the wheel and the tool rest.
  • Do not push the workpiece hard into the wheel

Hot materials/burns

  • Have a water dip next to the wheel, small water pans designed for this can be attached to the front and middle of the grinder.
  • Dip frequently to cool the workpiece.
  • Have ice available in the workshop for cooling a burn.
  • It is best to dip to cool leather finger cots may be useful-Do Not Use gloves.
  • Always cool a workpiece before putting it down and picking up the next one.

Grinding fingers

  • Do not push your fingers onto the wheel. Really. Really really.
  • Do not hold in such a way that you can slip and grind your finger or knuckle.
  • Do not talk to anyone or have any distractions while grinding
  • Move slowly and calmly while using the machine.
  • Many ground fingers result from rapid hand movements near the spinning wheel-move slowly and deliberately
  • Keep your fingers safely away from the surface and corners of the wheel, a divot in the finger or knuckle happens ridiculously easily on a grinding wheel (voice of experience)

Electrical fire and shock

  • Regularly inspect visible wires and plugs for condition.
  • Check to see it is properly grounded.
  • Use a proper grinding machine with a sealed bearing construction. Dust getting inside a grinding motor can start a fire.
  • Be careful of water spillage: you can get electrocuted or start a fire.
  • Make sure the wall socket and house wiring is rated and fused correctly for the load of the grinder (and other tools on in the shop at the same time).
  • Use a fused power bar for the grinder. Attach the power bar securely to the wall.
  • Always unplug the grinder before changing any parts.

Maintenance

  • Follow all directions in the instruction manual. If you don't have one call the manufacturer for a copy to work from.
  • Clean up dust and particles every time you use it.
  • Inspect wheels and wiring regularly.
  • Keep a log and make notes in it.
  • You maintain your car, why not your other mechanical tools?


All rights reserved internationally. Copyright © Charles Lewton-Brain. Users have permission to download the information and share it as long as no money is made-no commercial use of this information is allowed without permission in writing from Charles Lewton-Brain.
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