When it comes to polishing and grinding safety, there are a few common best practices that all operators should be aware of. Proper mounting of abrasives, use of guards, the right product for the job, correct speed (RPM), spark control, safety gear, and ergonomics are just a few considerations that need to be addressed before an operator even thinks of touching a workpiece.
When it comes to choosing the right abrasive product, Rick Hatelt, Ontario Territory Manager for PFERD Canada, said that oSa® certification is a must—reputable manufacturers belong to the Organization for the Safety of Abrasives (oSa) and the products certified are the safest you are going to get.
“Being oSa-certified is going to at least give you that assurance that the product is as safe as it can be for that application,” he said.
It is important to understand the difference between price and cost. Saving money on a tool may cost more in the long run. Even a minor workplace injury due to the use of a cheaply made abrasive wheel may cost the company tens of thousands of dollars or more in damages. Products that are oSa-certified conform to the strictest safety standards in the world. These tools are inherently safe and designed in such a way to ensure the safety of the operator; however, if operators choose not to follow proper procedures and techniques, they can create dangerous situations that don’t need to be.
“Every tool can malfunction,” said Dan Magwood, territory account manager for Ontariofor Flexovit Abrasives Canada, Brampton, Ont. “Guards come with machines for a reason. They are not attached to the tool when you take them out of the box. There is some assembly required. We see so many times where the box is in the garbage with the guard still in it. I know the government is having a ton of new inspectors coming in in the GTA alone, and one of the biggest things they are going after is not having a guard on thetool.”
Although Magwood said that guards can be cumbersome, there is a tool out there that will meet application needs, especially when it comes to getting into tight spots. Every tool is not universal; it can’t do every job.
“The most important thing to remember is that working with power tools has become much, much safer over the years, but as is the case with anything, if you do not follow the proper guidelines, the operator is much more susceptible to otherwise preventable accidents and injuries,” said Ryan Boyd, product manager, tooling and power tools for Walter Surface Technologies, Pointe-Claire, Que.
Each application has a different set of rules, but here are some common situations that pose potential safety hazards.
“Safety is obviously the No. 1 consideration in a shop, especially with young guys going into older shops,” said Magwood. “Picking up bad habits from the guys who have been around for 40 to 50 years doing it repeatedly can be a challenge.”
Some operators, after doing a lot of repetitive work, will look for short cuts to get the job done as quickly as possible, sometimes cutting serious safety corners along the way. According to Hatelt, one of the scariest things he sees on a regular basis is operators modifying grinding wheels to suit a particular job even if the wheels are not designed for the job. For example, Hatelt said that he has seen shop operators take a 7-in. grinding wheel, rated at 8,600 RPM, and dressing it down to fit into their 5-in. grinder.
“It’s not smart because a 5-in. grinder is 12,000 RPM,” Hatelt added. “Even though the wheels are oSa-certified and test above the 8,600 threshold, they aren’t tested at 12,000 RPM. That disc is spinning well beyond its safety rating, and that is scary and could lead to a very dangerous situation.”
When it comes to safety, choosing the right product for the application is key. Another major no-no Hatelt has frequently come across is people using a cutoff disc for grinding. He explained that the only way this is acceptable is if the operator is using a specific product designed for both cutting and grinding.
“Generally, we see operators using cutoffs every day; they grind the burr created with that same cutoff wheel, which creates a very dangerous situation. Most cutoff wheels are not reinforced for lateral stability, and when side-loaded, are prone to breakage and severe injury to the operator.”
Spark control is another consideration that all operators need to factor in when starting a job. Aiming the sparks to an appropriate area where there are no other workers or fire hazards is a simple task, but not always something operators take into consideration. Hatelt explained recently he was in a shop where the sparks were directed toward a cardboard wall. With the right conditions, the entire shop could have gone up in flames because of the negligence of the operator. Sparks also have the potential to burn surrounding workers if not aimed properly.
“I mean, you always want to try and grind and cut away from yourself,” added Magwood. “It’s common sense. We tell a lot of guys don’t look at a wheel, always turn it on down and away. If it’s going to break, it’ll be in the first ramp-up in speed. A lot of kids, when they first see it, want to watch. When they are that close to your face, they are spinning at 80 m per second, which can be very dangerous.”
Another important thing to note is the need for proper safety equipment. According to Boyd, if the proper safety equipment isn’t being used—wheel guard, safety glasses and/or face shield, gloves—then there is a serious risk of personal injury that can result in massive blood loss, damage to eyes or other vital organs, and even death in extreme cases.
With repetitive motion, operators often suffer from aches, pains, and weakened gripping. Ensuring operators are following proper exposure limits is a good start. There are also some great products and accessories that can make an operator’s job smoother, which in turn can increase productivity. But, it is also important to understand the limitations of both the operator and tool.
“For ergonomics, let the tool do the work,” said Magwood. “Some operators think that the more pressure they put on it, the faster it will go.
But it’s also that much more vibration. So, if you let the tool do the work, it’s much smoother. The product is there to be used at a certain pressure; the machine itself tells you how many amps you should be drawing when you are putting that type of pressure on there. That is huge.”
Hatelt explained that there is a condition dubbed “white-knuckle syndrome,” medically known as hand-arm vibration syndrome, that occurs when there is too much vibration over a long period of time, creating frostbite-like symptoms at the tops of the fingers. Prolonged exposure to vibration causes damage to the capillaries, preventing blood from reaching the tips of the fingers.
One way to deal with vibration issues is exploring accessories like anti-vibration handles, which dampen vibrations transmitted from the grinder to the hands. With reduced vibration, an operator can work longer. Oftentimes, when there is less vibration, you also have a quieter environment.
“Ideally, you always want to work in a comfortable position,” said Boyd. “Typically, you will always want one hand on the grinder handle and the second hand somewhere along the barrel of the grinder. The idea is to space your hands evenly so you have a good range of motion, no discomfort, but of course full control of the tool at all times.”
When it comes to specific applications, it is important to use the right tool for the job, especially when it comes to materials. Some products are designed with a specific material in mind and are often not designed to cut, grind, or polish anything beyond that. For example, Hatelt has encountered situations where products designed for steel are being used on stainless steel workpieces. Stainless and steel grind very similarly, and there would be similar risks involved, which is why operators sometimes work with both materials not realizing this can lead to contamination because steel products generally include additives that will contaminate and rust stainless.
Working on stainless in a steel environment can be a costly mistake. When steel particles in the air land on stainless, it can cause oxidation and corrosion on the workpieces. According to Hatelt, it’s important that operators be in a controlled environment when working with stainless steel to avoid cross-contamination.
“You always want to take a wheel off the machine,” said Magwood, adding that manyoperators will throw an angle grinder in their job box with the cutting disc or grinding disc on it, which puts extra pressure on the side of it. This could break a piece of fibre glass, which is the safety feature within bonded abrasives.
When operators do this and then bring the tool up to speed, suddenly it starts breaking apart, which is dangerous.
“For the 30 seconds it takes to take it off, it can save a lot of stitches,” he added. It is also important to note that all discs and wheels have a shelf life. Best practices dictate that operators should use the oldest first and rotate the product for the best results. When stock is stored, humidity plays a big factor in how the tools operate. It is important to minimize humidity as much as possible.
“It’s difficult to do that in Ontario,” explained Hatelt. “We’ve seen massive differences from one product to the next. It doesn’t necessarily affect safety, but certainly longevity.”
If you think about it, taking a humid product out of storage in a shop and then placing it in a frozen truck to go to the job site can cause the grinding wheel to freeze and crack, causing a dangerous defect. Extreme temperature changes are not ideal for discs andwheels, but humidity is a significant problem.
Overall, safety on the shop floor should be a serious priority for all. When it comes to cutting, polishing, and grinding, Magwood said that if it can cut metal, it can certainly cut through skin and bone. But the good news is the industry is seeing more and more younger operators prioritizing safety.