Power trowels give concrete the smooth finish often lacking in years past.
Power trowels are ideal for finishing concrete slabs, floors and foundations. They are much more efficient and effective in smoothing surfaces than the old method involving a board screed and a hand trowel.
Consider a number of things when renting basic troweling machines. What type of surface is being finished? Does the customer need float, finish or combination blades? How large is the surface, and should ride-ons be considered?
Ask what finishing steps need to be accomplished. This pertains to specification of blades and accessories.
If floating to level high spots and fill voids, float blades or pans are recommended. If finishing to seal and increase density in the slab, finishing blades are recommended. For both floating and finishing, combination blades might be acceptable and can save time on a blade change. Spare blades should be readily available because blades commonly wear out.
Also consider the size of the area to be finished. Smaller jobs or specialized finishing applications might be more suited to an edger trowel. Four-bladed power trowels can cover most any job. Ride-on trowels offer multiple rotors with four blades apiece to cover up to twice the surface area of hand-held units.
Machine operation When renting a trowel, advise customers how to achieve a better finish. The application makes a difference in how the blades act on the surface of the slab, and they can be controlled by changing the pressure and speed of the blade rotation.
When floating, the blades should be flat to distribute the pressure and weight of the machine evenly. The machine should run at half to three-quarter speed to prevent an uncontrolled condition and thus undesired marks on the surface of the slab.
On subsequent passes and into the final steps beyond floating, the blade pitch and speed of the machine should be increased to full throttle, and the highest pitch angle of the blades should be used. This will apply a greater pressure and force on the surface of the slab for densification to achieve the desired finish.
Actuation of a blade pitch affects the transition between floating and the final finish. The operator might want, or the application might dictate, infinite pitch adjustment through rotation of a knob or a preset pitch adjustment through faster means, such as the quick actuation of a lever.
Safety concerns When renting power trowels, as with any equipment, ask yourself if the machine is easy to operate, as is the case with a standard power trowel, or if it requires a more experienced operator, as a ride-on trowel would. Does the machine have safety features such as automatic emergency stops, vibration-reducing shock mounts, and handles and guards? Will the machine be used on a large square slab or in an area with hallways and tight corners, where an edger trowel might be more appropriate?
Also ensure that the customer can perform basic maintenance checks and that rental center staff as well as customers know what those checks are (tight hardware, unclogged air filters, properly adjusted belts and cables, and emergency stops, for example).
Construction sites are often the most susceptible environments for creating havoc with any type of machinery. Dirt and dust in the air as well as residuals from building materials and earth compaction can hamper the performance of the best-filtered and -sealed systems. It is vital to grease and lubricate moving components, change oil and clean and/or replace filters regularly. The better maintained the equipment, the longer and more reliably it will perform.
One of the most important elements to consider when renting a machine is its ease of operation. Ensure that all controls are well-labeled and that it's clear what each one does. Also ask yourself if the operator will require training to ensure that the machine does the job properly.
A machine isn't ready for a rental job if:
- It doesn't appear properly maintained.
- It appears to be leaking oil or fuel.
- It is difficult to start.
- It starts, but shuts off frequently.
- It requires that the operator be given special instructions to allow it to warm up.
- Its blades, air filters or shock mounts are worn or cracked.
- It has loose hardware.
To ensure successful operation, operators should have:
- The right machine for the job.
- A properly maintained machine.
- Proper training.
- An understanding of all safety devices.
Wacker offers ride-on power trowels for floating and finishing of large concrete surfaces. Available with two trowel sizes and overlapping/nonoverlapping machine options, each unit features twin lever direction control, a foot-operated safety switch to stop the trowel, front and rear lighting, an instrument console and a gearbox drive system that transfers maximum torque to the rotors, the company says.
The Dyma-Grinder from EDCO is easier to operate and four times faster than conventional grinders for repairing concrete slabs to depths of one-eighth to one-fourth inch, the company says. Equipped with a high-speed, 10-inch diamond disc, the unit can remove excess surface material, repair spalled or damaged concrete, and grind joints to an even surface. The Dyma-Grinder is available with electric, gasoline or propane power.
Diamond Products' 56-page Core Cut Saw Catalog offers detailed information on the company's complete line of concrete saws, masonry saws, wall saws, specialty saws, sawing accessories and power units.
Stow concrete mixers are available in three models: CM4, CM6 (pictured) and CM9. The CM6 is designed for small to midsize jobs and has a capacity of 6 cubic feet. It is available with four 5- to 8-horsepower gasoline engine options, a 5.5-horsepower diesel engine or a 1-horsepower single-phase electric motor. The unit loads from a height of 41 inches and pours from a height of 26 inches for easy transfer to standard-size wheelbarrows, the company says.
The EZ 650 (pictured) and EZ 1100 concrete breakers from Allmand Bros. are designed for indoor and outdoor applications. Both units feature adjustable drop heights and stroke settings, simple control panels and a variety of bit sizes. The EZ 650 delivers a 640-pound breaking weight and is powered by an 11-horsepower Honda gasoline engine. Engine options include propane, diesel and electric motor.
Kraft Tool manufactures hand tools for work with concrete, masonry, drywall and plaster. The company's catalog includes approximately 1,600 tools and features a new line of finishing trowels with Kraft's ProForm handle, which is designed to give the user a soft, textured grip.
Cemen Tech's front-discharge mobile concrete dispenser uses a cross conveyor rather than a cross auger to deliver aggregates and provides increased mobility with the front-discharge mixer. The unit features an engineering-class roller chain and a dual-auger cement feed system.
The WMS-Series of self-propelled roller screeds from Multiquip Whiteman provides a system that can do the bulk of surface strike-off work with only one operator, according to the company. Optional strike-tube sets allow each unit to reach 10-, 14-, 18- and 22-foot lengths. Features include an 18-horsepower Onan engine, an operating pressure rating of 2,000 psi, a hydraulic flow of 11 gpm, a 5-gallon fuel tank and drive-tube steering. Joystick controls steer the unit and correct alignment during operation.
Worksite Pro hydraulic breakers from John Deere, available in models HB15, HB30, HB50 (pictured) and HB75, are designed as attachments for the company's 200 Series skid-steer loaders. All models develop force through gas-assist and hydraulics, allowing for a higher power-to-weight ratio than breakers using high-pressure accumulators, the company says. The HB50 delivers 600-1,080 blows per minute.
Target's Dual Trac is a walk-behind floor grinder available with a 1 1/2-horsepower motor or an 11-horsepower engine. Applications include grinding brick, concrete slabs, stone and ceramic tile floors. The unit measures 22 inches wide and has built-in lift handles. Electric models have a single-point lifting bail, and gasoline models have a three-point lifting bail.
Wyco Tool's W9400 hydraulic paving vibrator features a flow rate of up to 4 gpm, operating pressure of 800 psi, a square head that measures 2 1/4 inches and a centrifugal force of 2,000 pounds at 10,500 vibrations per minute, according to the manufacturer. The standard hose lengths for the angled unit are 9 feet of hydraulic hose and 4 feet of protective hose. Hose lengths for the straight units are 9 feet of hydraulic hose and 6 feet of protective hose.
Elite Trenchers & Concrete Saws manufactures stainless steel and steel painted saws in four models. The ETSS16-inch CS (pictured) offers a 12.5-, 13- or 16-horsepower engine from Kohler, Robin, Honda or Briggs & Stratton's Vanguard line. The company says the unit can be used to wet or dry cut.
Stone Construction Equipment's Smooth Operator power trowels are available in 30-, 36-, 46- and 48-inch diameters with three- or four-blade configurations. Each model features a cast-iron spider, a rotating stabilizing ring, variable blade adjustments and a shock-mounted ring guard to reduce vibration and chatter. The company's Dyna-Clutch system is standard on all trowels and is designed to stop blade rotation without shutting off the engine. Engine options are Honda, Briggs & Stratton, Robin and Wisconsin.
The Gator Rig 2 core-drilling rig from Wel-Co Metallurgical has a standard bit capacity of 10 inches and a 14-inch maximum. Available with or without a vacuum, the unit is equipped with a dual switch/outlet control panel, an amp meter, a slide handle, a 13.5-by-16-inch cast aluminum base with four leveling screws and a quick-change adapter for conversion from anchor to vacuum base, the company says.
The Hammerhead mechanical breaker is a backhoe attachment from Bosma Total Quality Manufacturing that can demolish concrete flatwork up to 10 inches thick, according to the manufacturer. As the backhoe's down force fires the trigger mechanism, the breaker impact rod generates 1,200 foot-pounds and fractures the concrete's subsurface, allowing for easy excavation of the debris. The Hammerhead attaches to all major backhoes that exert a down force of at least 3,000 pounds.
Arrow-Master's AS60 gas-powered aluminum screed can expand up to 60 feet, the company says. Weighing 8 pounds per foot, this sectional unit features an A-frame design. Sections are available in 2 1/2-, 5-, 7 1/2- and 10-foot lengths. Other features include the choice of a Honda or Briggs & Stratton engine and Arrow-Master's Curl-Edge runner to eliminate concrete roll-over.
Crown Construction Equipment's C9C concrete mixer is available with a variety of electric, gas and diesel power options. The abrasion-resistant steel drum has a capacity of 9 cubic feet and features two sets of steel blades to provide a smooth concrete mix, the company says. The highway-towable unit features high-speed taper roller bearings and an optional rubber torsion suspension system.
The AS 380 from Allied Construction Products' AS Series of hammers is a hydraulic impact hammer that can demolish concrete structures, trench rock, building foundations and pavement, the company says. The unit can be mounted on a 12,000- to 25,000-pound backhoe/loader or a 15,000- to 30,000-pound excavator and delivers a force of 522 foot-pounds with a hydraulic flow of 23.5 gpm.