How to Control Dust when Cutting Concrete, by Concrete Network

Controlling respirable crystalline silica dust can prevent lung conditions like silicosis, COPD, tuberculosis, and lung cancer. The best way to do that, aside from wearing a respirator, is wet-cutting. However, wet-cutting has disadvantages: it’s messy and not suited for indoor cutting, not all saws are equipped for it, and cutting sites don’t always have access to water.

Using a vacuum to control dust is less preferable to wet-cutting, but it has the advantages of being easier to set up and clean up. This video from ConcreteNetwork.com showcases three kinds of vacuums, from Shop-Vac-type vacuums all the way to HEPA filter-equipped monsters. Watch it now, and let us know what you think in the comments section.

How to Cut Safely with a Diamond Blade and Handheld Saw

To get ready for the ACE14 conference and for all the guys who get stuck down in the trenches cutting pipe, we’d like to offer this article on how to use diamond blades and handheld saws safely. It includes things what you should check before you start cutting and what you should do while you’re cutting. Follow them and stay safe!

Remember to visit us near the tapping competitions in Booth 2466 (PDF) at the ACE14 conference in Boston, MA from June 8 to 11! 

Before Cutting

• Make sure that you’re well-rested. You’ll hold the saw closer to your body if you’re tired, which will increase your chances of injury if your saw kicks back.
• Make sure you’re trained in how to hold and cut with your saw properly and safely.
• If anyone’s helping you, make sure that they’re properly trained and know how to assist you properly.
• Wear proper safety gear, including safety glasses and footwear, headgear, and eye and hearing protection. Avoid wearing anything that could get caught in the blade, like jewelry or loose clothes.
• When cutting brick, block, stone, or concrete, use a respirator. It’ll protect you against lung diseases like lung cancer, silicosis, and pneumoconiosis.
• Only cut materials recommended by your blade’s manufacturer. Using your blade on improper materials can endanger your safety and cause excessive blade wear and damage.
• Don’t mount your blade on a saw that doesn’t meet the minimum requirements set by the blade’s manufacturer.
• Don’t mount your blade on any type of machine other than those recommended by the blade’s manufacturer.
• Don’t dry-cut unless your blade is specifically designed for dry-cutting. Dry-cutting with a wet-cutting blade can weaken the welds holding the blade’s cutting segments and endanger your safety.
• Don’t use a wet-cutting blade without sufficient water. If you do, you’ll weaken the blade’s welds and endanger your safety.
• When cutting with a wet-cutting blade, make sure that the blade has an adequate and continuous flow of water. Neither gravity feeds nor the “booster pumps” on your saw will supply enough water to a wet-cutting blade.
• Make sure you feed the right amount of water to your blade. Too much water can cause blade polishing, while too little can turn the cuttings into a paste that can jam or bind your blade and cause kickback.
• Use segmented blades instead of toothed blades. If you must use toothed blades, make sure that they have enough “tooth set”, or room between the sides of the blade and the sides of your cut, to prevent binding and kickback.
• Never mount your blade on a saw with a higher RPM than that recommended by the blade’s manufacturer.
• Make sure your blade is the right size for your saw and job.
• Inspect your blade for damage, even if it’s new. Look for cracked segments or cores, missing or damaged segments, undercutting under the segments, warped cores, and damaged or out-of-round arbors. If you find any of these or any other kind of damage, the blade is unsafe to use. Throw it away.
• Make sure your blade doesn’t have foreign or abrasive material on its sides. These can increase your blade’s thickness and friction during cutting, which can lead to binding and kickback.
• Make sure the blade’s arbor hole is the right size for your saw’s shaft and is mounted between proper flanges. Don’t try to force it onto an undersized shaft, as this can endanger your safety and cause excessive blade wear. Don’t try to alter the size of the arbor hole.
• Make sure the blade is properly supported on your saw’s shaft and doesn’t slip or wobble.
• Don’t use an arbor hole bushing if you’re going to mount your blade on a high-speed saw.
• Make sure your saw is in good working order, is safe, and complies with all safety requirements.
• Make sure that your saw’s shaft bearings don’t have end or radial play.
• Set your saw’s lead-off adjustment so that the blade will travel straight.
• Check your saw’s pulley for excessive wear.
• Tighten the V-belts on your saw if they need it.
• Make sure the flanges are properly assembled, in place, of equal or proper diameter, don’t show excessive wear, and are clean and flat.
• Make sure your blade is mounted correctly on your saw and spins in the right direction.
• Hand-tighten the blade to your saw with a wrench that’s no more than 8″ long. Don’t tighten the mounting nut too much.
• Make sure your saw’s blade guards are in place, undamaged, and properly secured. Don’t try to pull or tie them back or otherwise defeat them.
• Check all the fluids in your saw.
• Make sure you have enough room to make your cut safely. If you have to, establish a safe zone.
• Make sure that the material that you’re going to cut is supported so that it won’t sag. This will prevent the material from pinching your blade, which can cause kickback.
• Make sure that you’re aware of all hazards both before and during your cut.
• Set your cutting depth to no more than 1/4″ greater than the thickness of what you’re cutting. Doing so will prevent your blade from contacting foreign objects once you cut through and will prevent kickback.
• Don’t use a saw that’s too heavy for you to control.

During Cutting

• Hold your saw firmly with both hands.
• Don’t stand directly in line with your blade when starting your saw or during cutting. This will reduce your chances of being injured if your saw kicks back.
• Before starting your cut, free-run your saw to make sure that it operates smoothly.
• Make sure you can properly rest the saw’s shoe on the clamped, supported portion of your material before cutting.
• Let the blade spin up to full speed before starting your cut.
• If you’re re-entering a cut, align your blade first, then ease it into the cut to prevent binding and kickback.
• Maintain your balance and footing at all times. Never cut on a stepstool or ladder or cut in an awkward position. Mount the saw on guide tracks if you have to cut above your shoulders.
• Don’t lean into your cuts. If you lean in to your cuts, your body will be closer to your saw, which will increase your chances of being injured if your saw kicks back.
• Don’t force your blade into your material. Your blade should be able to bite into your material and then continue cutting with nothing more than the weight of your saw. Forcing the blade can cause overheating, binding, or blade damage.
• Take your time. Cut with a slow sawing or reciprocating motion.
• Don’t cut or let anything touch the upper front quadrant of your blade. This will prevent kickback.
• Use greater care when cutting material with foreign objects in it, like reinforced concrete. Your saw can kick back when the blade encounters these objects.
• Don’t try to make your cuts in one pass, especially with dry-cutting blades. Use several passes until you reach your desired cutting depth.
• Never let your blade overheat. Remove dry-cutting blades periodically and let them free-run to air-cool.
• Don’t exceed the blade’s maximum RPM while cutting.
• Make sure the material doesn’t roll, slip, or vibrate. These can all bind the blade and cause kickback.
• Don’t grind with the sides of your blade unless your blade is designed for grinding.
• Don’t pry or push material with your blade.
• Make only straight cuts. Never twist, turn, or deflect your blade in the cut or make off-center, crooked, curved, or radii cuts.
• Avoid long-term, repetitive cutting, which can tire you out. When you’re tired, you’ll hold the saw closer to your body, which will increase your chances of being injured if it kicks back.
• Take your finger off the trigger or power switch after making a partial cut, if your blade binds up, if your saw stalls, or if power is interrupted.
• Allow cut-off pieces to fall away to prevent binding and kickback.
• Ease up on the saw near the end of your cut. This will prevent the blade from hitting the floor or foreign objects and prevent kickback.
• After you finish your cut, keep your blade in the cut until it comes to a full stop.

Works Cited

Daily, Sean D. “From the Archives: How Do I Prevent Chainsaw Kickback and Circular Saw Kickback?” Desert Diamond Industries Blog. Desert Diamond Industries, 6 Dec. 2013. Web. 28 May 2014. < https://desertdiamondindustries.wordpress.com/2013/12/06/frequently-asked-questions-how-do-i-prevent-saw-kickback/ >.

Daily, Sean D. “Safe Dry-Cutting with Diamond Blades.” Desert Diamond Industries Blog. Desert Diamond Industries, 5 Mar. 2014. Web. 28 May 2014. < https://desertdiamondindustries.wordpress.com/2014/03/05/safe-dry-cutting-with-diamond-blades/ >.

“How Diamond Blades Work.” How Diamond Blades Work. Norton Construction Products, n.d. Web. 28 May 2014. < http://www.nortonconstructionproducts.com/application/diamond-blades.aspx >.

“Pavingexpert and Pulvex – Cutting with Diamond Blades.” Pavingexpert and Pulvex – Cutting with Diamond Blades. Pulvex, n.d. Web. 28 May 2014. < http://www.pavingexpert.com/diamond_blades_01.htm >.

“Safety Tips When Dry Cutting With Diamond Blades.” Safety Tips When Dry Cutting With Diamond Blades. ChinShine Diamond Tools Co., Ltd., n.d. Web. 28 May 2014. < http://www.diamond-blade.org/technical-article/2013/1116/110.html#.U4XoqfldV8E >.

“Wet Cutting – Diamond Blades.” Wet Cutting – Diamond Blades. Norton Construction Products, n.d. Web. 28 May 2014. < http://www.nortonconstructionproducts.com/solutions/wet-cutting.aspx >.

Safe Dry-Cutting with Diamond Blades

Despite what you may have heard, you don’t always need water when cutting with a diamond blade! Dry-cutting even has advantages over wet-cutting: you don’t need to clean up slurry after you’re done, you can cut in places without reliable water sources, and you’ll tend to get cleaner, crisper cuts.

That being said, you can’t just slap any old blade on your saw and go to town without knowing what you’re doing.

First of all, you need to use a blade that’s designed for dry-cutting (may we suggest our Ductile Iron Safety Blade?). That’s because the water used in wet-cutting cools the blade. Cut without this cooling water, and you’ll quickly destroy a wet-cutting blade. Even worse, the heat will weaken the welds holding the cutting segments onto your blade, and if those segments break off during cutting, they may injure or kill you.

Second, you need to cut differently when dry-cutting. That’s because dry-cutting blades are cooled by air while cutting, and that air can’t get to the blade if you bury it deep in a cut. To get around this, you should step-cut – that is, cut an inch or so deep at a time – and periodically take the blade out of the cut to let it free-run and cool down.

Third, you need to wear a respirator when dry-cutting, especially if you cut concrete, brick, block, and stone. That’s because the water used in wet-cutting is one of the best ways to reduce dust while cutting. Without this water, you’ll inhale more silica dust, which can lead to lung diseases like silicosis, pneumoconiosis, and lung cancer.

In short, we’re not saying that you shouldn’t dry-cut. If you do, though, make sure that you have the right blade, the right cutting technique, and the right safety equipment for the job.

Saw Arbor, Cutting Depth, and RPM Chart

Wondering about your saw’s arbor or the cutting depth and maximum RPM of your blade? Wonder no more! We’ve gathered cutting depth and RPM data from Husqvarna and our own saw arbor data and gathered it all into one handy document. Download it for free today!

Recommended RPMs, Tool Arbors, and Cutting Depths by Desert Diamond Industries (PDF)

When Do You Replace a Worn Out Diamond Blade?

First of all, remember that a diamond blade is different from a knife blade or toothed saw blade. Because of this, it won’t have dull edges or dull teeth when it’s worn out. (In fact, we’ll bet that your diamond blade’s cutting segments look dull whether they’re worn out or not)

That’s because a diamond blade cuts with the diamonds impregnated into its cutting segments. These diamonds wear down during cutting, despite being one of the hardest substances on earth. When these diamonds are worn out, then your diamond blade is worn out, and you’ll need to replace it [1].

How can you tell this? Simple. Before your diamond blade is worn out, it’ll cut slower and slower and eventually won’t cut at all [2]. You should also look at the blade before you start cutting to see if the blade core has worn-out spots [3] or if the cutting segments have completely worn down [4].

Keep in mind that you can’t always gauge the life of your diamond blade by its cutting speed. Some blades will become “glazed over” if they’re too hard for the material that you’re cutting. You can usually restore these blades by running them through something abrasive, like asphalt, instead of trying to replace them [5]. In other words, the best way to determine if you need to replace your diamond blade is to look at it.

Did this article help? Let us know in the comments section!

Works Cited

[1] “How Do Diamond Blades Work?” Desert Diamond Industries Blog. Desert Diamond Industries, 27 Aug. 2013. Web. 10 Dec. 2013. < https://desertdiamondindustries.wordpress.com/2013/08/27/how-do-diamond-blades-work/ >.

[2] Wang, Hanjiang. “FAQs for Tile Saw Blades.” Diamond Blade Select. N.p., 19 Sept. 2009. Web. 10 Dec. 2013. < http://www.diamondbladeselect.com/tool-faqs/faqs-for-tile-saw-blades/ >.

[3] “Making the Cut – A Diamond Blade Work Wonders.” ToolGuy.com. N.p., n.d. Web. 10 Dec. 2013. < http://www.toolguy.com/diamond-blade.html >.

[4] “All Purpose Diamond Blade – Cutting Tips & Specifications.” Fire Rescue Blades of Delray Beach, Inc. N.p., n.d. Web. 10 Dec. 2013. < http://www.firerescueblades.com/resources >.

[5] “Frequently Asked Questions.” Desert Diamond Industries. N.p., n.d. Web. 10 Dec. 2013. < http://www.desertdiamondindustries.com/frequently-asked-questions.php >.