A Cut Above
By Tom Inglesby
Handheld saws go where the cuts need to be made, even high above the site on scaffolding and mast climbers. Here is a quick overview of how and when to use each type.
Diamond-blade masonry saws are, as we all know, not really "saws" at all but specialized grinders. Hard to tell by looking at them however, as most reflect the "traditional" saw format found in carpentry. Masons can opt for small tuckpointing grinders, larger circular saws, gas-powered cut-off and ring saws, and even chain saws. The problem isn't the variety; it's making the right choice for the job at hand.
Tuckpointing is a dusty, arm-tiring job. Using the common four-inch diamond-blade hand grinder is giving way to more specialized equipment such as the new Bosch 1775E, a five-inch grinder designed specifically for professional tuckpointers. This new unit for masons is good for removing mortar from a 50-story building or cleaning up a residential chimney, and Bosch claims the 1775E will get the job done virtually dust-free.
According to a Bosch spokesman, the biggest enemy to equipment is usually dust. A good practice is to regularly blow out the tool with a compressor each day after use.
The biggest mistake in tuckpointing, however, comes from trying to remove too much material at any one time. This makes the tool work harder and is harder on the motor. Instead, it's better to make multiple passes in smaller areas at one time. This is more efficient on the equipment and guarantees you won't gouge out more than planned.
In fact, specialized tuckpointing grinders such as the Bosch 1775E utilize a special hood for both dust and depth control. This unique tool easily hooks up to a vacuum to avoid a mess, and the specially designed depth gauge allows the user to select how deep they want to grind. Additionally, it has a window so the user can watch their work.
While the motor is the heart of the grinder, the diamond blade is the heart of the job. Picking the right blade can make a big difference in how much work the motor ? and tuckpointer ? has to do. Tuckpointing blades are usually in the four- to five-inch range and a minimum of 1/4-inch thickness. Some care in using the grinder will also pay off in longer blade life. For example, avoid striking the brick face with the blade; ease the blade into the work to prevent gouging the material and wearing the blade unevenly; and store blades in a dry environment to avoid rusting. Also, do not use any blade beyond the proper depth designed for the wheel. This will prevent undercutting that can cause the diamond segments to glaze over, requiring the user to dress the wheel.
Found in every home workshop, the circular saw has made many a cut in wood. On the masonry job site, similar saws are cutting brick and block in some out-of-the-way places. According to Brian Fortner, Sales Manager for Lackmond Products, Kennesaw, Ga., "A compact circular saw like our LP250 is ideal for use on various tile materials that have become ever popular in the building trades. It takes a 4.5-inch blade, so the immediate up-front cost savings on the smaller diameter diamond blade is also very attractive to the end-user."
The Lackmond LP250 runs off a standard 110-power source, building wire or portable. At a suggested list price of $143, the saw comes with a water kit, blade and everything needed to begin cutting. The saw uses standard masonry blades, such as the turbo-style, with a continuous, castellated rim that gives a wide cutting diversity and performs very well on brick, concrete, stone aggregates and roof tile.
The fact that the saw can be taken up on the scaffold ? and dropped from that perch ? makes some of the care and feeding tips different than with a table saw. Fortner notes, "Blades should always run in accordance with the directional arrow shown on the blade. Water as a coolant is always a plus when using the supplied water kit. The water keeps the blade cool and allows for easier cutting and maximum blade longevity."
MK Diamond manufactures a wide variety of masonry saws including a number of hand held units. According to Brian Delahaut, Vice President of MK Diamond, "Hand held masonry saws are one of the most widely used and versatile saws for masons. But masons often fail to consider the electrical power requirements of a masonry saw. The electrical requirement is the most important consideration when choosing any masonry saw."
He adds, "Masons must also consider the type of blade being used. While all blades claim to be designed for cutting masonry materials not all of them are designed for handheld saws. Consideration always should be given to the quality of the blade."
The most important way a mason contractor can improve the life of any masonry saw is to clean the saw after each day's work and to replace those parts that need to be replaced as a result of wear or use.
Contractors must also consider an effective maintenance program that includes daily cleaning of the air filter and tightening of the drive belt. "Failure to do either of these basic maintenance steps will mean that the handheld saw will have reduced performance and length of use," claims Delahaut. "Tightening the drive belt will ensure that the maximum amount of power/torque is transferred. One more thing: If a blade is being used dry, allow the blade to cool periodically by lifting it from the cut for a few seconds to ensure the blade does not experience any core failure or damage."
Speed and Power
The next step up in size and power is the gas-powered cut-off or high-speed saw. Used extensively in cutting openings, grooving concrete and other heavy applications, the high-speed saw also finds its way up on scaffolding to provide quick brick and block trimming far away from the table saw.
Many companies make these workhorse saws, each with some feature set that makes it a little different. Partner Industrial USA, a division of Electrolux Construction Products, makes saws for masonry and concrete applications in a wide variety of form factors from cut-off, high-speed saws to ring and chain saws.
In fact, Partner invented the ring saw, a variation that allows significantly deeper cuts into block walls, for example, than regular high-speed cut-off saws. In the mid-80s, Partner patented the hydraulic ring saw where the drive disk rotates the ring blade from the inner edge of the blade, not the center where the axle limits the cutting depth. With its ring cutting principle and 10-inch cutting depth, the Partner K 950 Ring Saw also has the maneuverability and versatility of a gas-powered saw.
Most masonry applications on brick would call for a saw like the K700 or new K750 high-speed saw, however. Even using a 12-inch blade, the saw can cut four inches deep and easily cut brick. The saws are lightweight and therefore easier to carry and use at the site where the brick needs to be cut ? such as on the upper reaches of a scaffold.
Compared to a Partner or Bosch, Diteq Diamond Tools in Blue Springs, Mo., is a tiny company. But as is often the case, being small doesn't mean it should be ignored. Diteq imports the Tequick high-speed saw from Emak of Italy that offers some solid features for masons.
With 4.7 and 5.7 HP engines available, these saws offer high power-to-weight ratios, something that masons can appreciate. The cut depth of five inches is reasonable for most brick applications, and the saws come with a standard wet kit for dust control. A multi-stage progressive oiled foam and paper air filter system extends run time and reduces filter costs.
Probably the most important thing to remember with high-speed saws is to keep the filter changed and to use the proper mixture of oil and gas when refueling. Standard maintenance applies, but these two items seem to come up more than others, especially when cutting dry. Keeping a saw in good shape will also make the diamond blades last longer, and that can save a mason a lot of money over the course of a job.
Dirt and dust are the enemies of all high-speed saws, and when you are cutting brick or block dry you create a lot of dust. Partner claims its "Active Filtration" system as a very big plus. Active filtration helps to keep that dust away from the filtration system, which means less dust that has to be filtered. The longer an operator can cut without interruption, the better the productivity.
Blades for high-speed saws also come in a variety of styles. If a mason knows what material will be cut, block for instance, and has enough work on a particular job, it would pay to buy blades designed just for block. The blades will cut well and last longer than the general purpose blades that are often used.
Conversely, on a job that has particularly hard brick, it would pay to use a softer blade to cut the brick. The blade will cut faster and stay sharp for the duration of the job. No time will have to be spent sharpening the blades, and when blades cut well it is easier to make straight and perpendicular cuts and increase productivity. On larger jobs the extra expense of using the right blade gets paid back by the increase in productivity and product life.
When cutting, make sure your saw is running full speed before you begin your cut, rather than starting with it at half speed and increasing the speed once in the cut. This will help to make sure that the blade stays on course as you cut. Twisting or wiggling the blade in the cut is bad for the blade and can make it wear prematurely.
Take care of the blade when you aren't using it. Don't toss the saw with the blade on it in the back of your truck. A blade that gets even a little dented or warped will show it when you use it. Spinning at 4,500 to 5,000 RPM makes it very obvious when this happens. Blades showing this type of damage should be removed from service.
Chain Saws Go Deeper
Our final saw format is one that gained its reputation high up in trees, not on scaffolds. The chain saw might seem like a strange format for a mason to be using, but it has some significant design features that can be handy on the job.
Chain saws are used on jobs where plunge cuts, square corners, mitered or other precision cuts are needed, or where rebar has to be cut. Other situations that might warrant a chain saw include dust-free environments or non-percussive tool requirements.
Some typical uses are installing electrical boxes, cutting openings for windows or doorways, making beam pockets and scupper holes, or the precision removal of damaged materials. They are also used in restoration of older, non-reinforced brick buildings, and remodeling where wet-cut dust control is needed for safety or cleanliness.
A new entry in this market in the U.S. is the ICS Redzaw. This chain saw has the ability to plunge cut, cut square corners as small as three inches with no over cuts, do precision cutting or cut rebar. It is lightweight (under 21 pounds), portable, gas-powered and uses inexpensive replacement chains that are priced from $149. It also has no kick-back or abrasive style cutting, and is easy to use. Redzaw claims first-time cutters can make accurate cuts in less than 30 minutes.
Because this form isn't as familiar to masons as the circular-blade styles, some tips are in order for getting the most from the equipment. The saws run on 25:1 gas-oil mixture and requires water at 20 PSI for cutting. Chain tensioning is highly recommended after every tank of fuel ? a saw runs for about 15-20 minutes on a tank of fuel.
For cleanup, simply rinse the saw off with fresh water, especially the bar/chain, the starter and the clutch cover; then lightly oil the bar and chain.
Other recommendations include checking the air filter for debris after every five to six tanks of fuel and flipping the bar over after every three to five chain adjustments to extend the bar and chain life. Be sure not to over-tighten the chain, as it will prematurely wear out the clutch, bar and chain. As with all gas motors, use fresh gasoline. And in cold weather, store the saw inside in a heated environment prior to starting.
The blades are also unfamiliar to many workers in the masonry trade, so here are the recommendations from Redzaw for care of the chain. "There are various Redzaw blades designed for masonry applications. For example, the Wide Kerf blade is designed to fit in the cut of the Redzaw chain saw with .210-inch kerfs and is used when cutting square-cornered openings with both a cut-off saw and diamond chain saw for the corners. In choosing a chain saw chain/blade, blade life, economy, materials to be cut ? including rebar and abrasive block ? should all be considered."
Anything that the mason can do to improve his or her work should be considered when looking at cutting tools. Adding a chain saw to your truck might seem strange at first but, in those applications where you require plunge cutting or small opening cutting, there might not be a better choice.
About the Author
Tom Inglesby is a San Diego-based freelance writer whose work has appeared in numerous online and print publications. He is the winner of the Construction Writers Association's 2002 Boger Award for Special Reports.