Understanding a concrete saw's power options is vital in tool selection.
Choices in concrete saws are more plentiful today than ever before. With rental centers having an enormous amount of product information to sift through, choosing the right concrete saws can be difficult. A basic understanding of concrete saws' power source options is important before selecting the saws you plan to offer your customers.
Concrete saws are powered by gasoline, electric, hydraulic, diesel or air motors. Here are the pros and cons of each:
The most common type of concrete saw is one with a gasoline engine. These saws come as small as the 2.5-horsepower models usually found in green concrete saws up to 72-horsepower highway production saws. Gas-powered saws range in blade capacity from 8 inches to 54 inches.
The advantages of gas-powered concrete saws are their relatively inexpensive initial cost and parts that are more readily available, less expensive and easier to repair compared with those needed for other saws. Gas-powered saws typically have a smaller package per horsepower with less vibration than diesel models and are lighter and easier to operate than similar-size non-gas saws. The drawbacks to gas-powered saws are shorter engine life than hydraulic or electric versions, higher fuel consumption and higher emissions.
Electric concrete saws are the only ones approved by the Occupational Safety and Health Administration for confined areas. These saws are quiet with low vibration and no heat or exhaust generated at the operator. Electric saws offer lower energy costs and motors that are less expensive to replace than other saws' motors.
The negatives of electric concrete saws are the dangers of electric shock and the need for cords and plugs. Saws with larger (more than 7.5 horsepower) motors need power sources that can handle three-phase motors. A generator or power box at the job site is required (and the distance the saw can be operated away from it is limited) along with a ground fault interrupter. Also, repairs require an electrician instead of a general mechanic normally used to repair gas saws, and the saws deliver less weight over the blade shaft.
Hydraulic concrete saws range from 13 to 25 horsepower and have blade capacities of 14 to 26 inches. Their motors produce less noise and are cheaper to maintain than gas or diesel models. The disadvantages of these saws are the requirement of a hydraulic power supply and the potential for hydraulic oil leaks. Also, the operator usually has to keep the saw close to the hydraulic power pack (150 feet of hose is recommended for these saws), and like electric saws, hydraulic saws deliver less weight over the blade shaft than gas-powered saws.
Concrete saws are available with diesel engines ranging from 22 to 72 horsepower. Because they are heavier and designed for the larger-scale jobs of concrete-cutting professionals, diesel-powered saws are rare in the rental market.
Finally, air-powered saws are small, lightweight and portable. They can be operated at any angle, are low-maintenance, emit no exhaust fumes and do not have a direct drive that needs a belt upkeep. With these pros come the limitations of power and mobility - air saws need air lines connected to a compressor. They usually are limited to 4 horsepower and a 14-inch blade capacity.
Diamond Systems
Diamond Systems' DS-40 is a coring rig for use with diamond core bits up to 10 inches in diameter. Powered by a two-cycle gas engine, the DS-40 features a centrifugal clutch and a gearbox drive mechanism. The water swivel accepts all standard 1 1/4-inch, seven-ended diamond core bits. The unit has throttle controls and support handles and is suitable for reinforced concrete, masonry, concrete pipe and remote core sampling, the company says.
Tramac
Tramac's 140 hydraulic breaker is designed for loader backhoes and mini-excavators from 4.5 to 13 tons. Applications include road repair, in-plant demolition, interior gut-out and other demolition jobs. The 815-pound unit has a tool diameter of 3 inches with a recommended flow range of 19 to 32 gallons per minute. The operating pressure is 1,800 pounds per square inch, and the striking rate is 845 to 1,160 blows per minute.
U-Cart of America
U-Cart of America completely redesigned its agitating trailer. Powered by a 5.5-horsepower Honda engine and hydraulic motor, the trailer has twice the lifting power of its predecessor and can lift and dump concrete at the job site. The agitator blade maintains consistent churning of wet concrete and reduces settling.
M-B-W
Models F78, F88 and F96 in the Ride-On Power Trowel Series from M-B-W feature low center of gravity, the company says. Each unit is equipped with a variable speed clutch, a chrome ring guard and a Honda or Kohler engine. Options include combination blades, float blades, float pans, adapter blades, transportation carts and spray systems.
