Maintaining and repairing hard surfaces - streets, highways, building exteriors - is a never-ending task.
To ensure that repairs last, surfaces must be properly prepared before overlays, paint or protective coatings are applied.
There is high demand for surface preparation equipment rentals and there are many types and sizes of surface preparation machines to choose from, as well as many options and accessories. To take full advantage of this vast and various market, rental store people must do their homework and determine what type of equipment is most often called for in their areas. But this overview will help you get started.

Equipment for working on concrete
Concrete surface-preparation equipment cuts, cleans, levels, smooths or roughens and adds texture to or removes it from paved surfaces. Here's a sampling:
Concrete saws cut slabs and contraction joints for making asphalt patch repairs and traffic loop installations. Push models use blades ranging from 14 to 16 inches in diameter. Larger self-propelled units accommodate blades as large as 36 inches. Blades are available for cutting various materials. Many models offer both downcut and upcut blade rotation. Power options include gasoline and propane engines and electric and air motors.
Grinders use rotary disks to create smooth, level surfaces. Disks are available for different materials, including concrete, terrazzo, tile, brick and stone. Grinding also re-moves rust and mildew.
Scarifiers have rotary cutting wheels that penetrate paving to a controlled depth. They can be used to level uneven joints and damaged slabs of paving, to make grooves in walkways and to remove traffic lines, paint and other coatings from paved surfaces.
Scabblers use compressed air to hammer sharp bits into concrete surfaces to roughen them.
Chisel scalers, also powered by air, are hand-held tools that produce a rapid hammering action to remove almost any type of hardened material. They can be used on flat and vertical surfaces and are good for working on hard-to-reach spots.
A small air compressor is needed for power, and vacuum equipment will help control airborne dust. Some projects are in areas that require dust-free environments, necessitating vacuum equipment.

Blast-cleaning equipment
Portable abrasive blast-cleaning systems use compressed air to propel abrasive particles at the surface to be cleaned. Blasting leaves surfaces ready for coating or bonding. A self-contained abrasive blast-cleaning system includes an air compressor. Various abrasives are available for different surfaces. Models range from compact units that can be moved around a job site by one crew member to large systems mounted on trucks or trailers. A machine's capability is stated in the quantity of abrasive it can accommodate. Two-, 4-, and 6-cubic-foot models are popular rental sizes, but big units with multiple outlets have capacities of more than 150 cubic feet. Blasting machines remove old paint, rust and other contaminants from structural steel, bridges, storage tanks, water towers and other structures so they can be repainted. On concrete, blasting removes latent cement, form marks and discolored areas to expose colored aggregate. Masonry is blast-cleaned to prepare it for sealers and painting. Blasting stucco and brick removes loose paint, mildew, stains and graffiti, leaving the surface ready for coating. Carefully controlled use allows blast cleaners to strip paint off houses and boats and to clean fiberglass, aluminum and other sophisticated metals.
New media, including wheat starch and bicarbonate of soda, used with low-pressure equipment can strip coatings from advanced composite materials used on aircraft, automobiles, trucks and boats.

Who uses surface preparation equipment
Some homeowners rent small concrete machines to work on walks and driveways, but this equipment basically is rented by contractors. Abrasive blast equipment should be used by professionals proficient in its operation. Concrete machines are rented by highway and bridge contractors; paving contractors; county and state highway departments; municipal street, water and sewer departments; airports, utility companies, utility contractors; electrical contractors; building and maintenance departments of businesses and industrial operations; and federal government agencies, including military installations. Abrasive blasting systems are rented by many of the same professionals who use concrete equipment and by painting, sandblasting and flooring contractors and a variety of industrial customers, such as shipyards.

Operation
Surface preparation equipment should operated by qualified personnel. There may be some homeowners who have construction experience and can effectively use compact concrete machines, but most of this equipment is not for the average renter.
Show blasting machine renters how to couple hoses and remote control lines and how to manually depressurize the system before attempting maintenance or repair. This type of equipment requires maintenance during the work day. Moisture separators must be drained regularly. Some machines have abrasive traps that must be cleaned twice a day. Inspect hoses, couplings, control lines and control handles daily. Compressors often concentrate moisture from the air and send it down a machine's air line, causing an abrasive clump to form, blocking the metering valve.
Clemco Industries, Washington, Mo., publishes an excellent book that provides generic information on abrasive blasting: Blast Off 2, Your Guide to Safe and Efficient Abrasive Blasting. For information on ordering the 177-page publication, call Clemco at 636-239-0300.

Safety
Surface preparation equipment poses hazards for operators and any other people in the work area. Concrete saw blades, disks and cutting wheels can hurl debris at high velocities. Never operate equipment without guards or shields. Dust from the work area also can cause respiratory problems and affect vision. Encourage customers to use all safety equipment and protective clothing recommended by the manufacturer. The operation of this equipment involves many dangers and a complete understanding of the equipment is essential - review all possible dangers with your customer. Abrasive blasting equipment, for example, cleans by releasing a powerful stream of sharp particles, so it is especially important to secure the work area with barricades and tape to keep onlookers out. Some applications produce clouds of toxic dust, so operators must use respirators and wear prescribed safety clothing.
In the United States, OSHA enforces regulations governing the safe operation of abrasive blasting equipment. State safety regulations also may apply. Local safety agencies can provide current information on all safety requirements.

Opportunities for add-on sales and rentals
Customers who rent concrete surface preparation machines often need other equipment and tools. Scrabblers and chisel scrapers require separate air compressors as a power source. Keep a good inventory of saw blades and grinding discs. Discs must match job conditions, so renters may need to purchase several types of blades and discs to meet all requirements.
Concrete projects often require screeds. Extra concrete finishing tools may be needed, too.
Renters of blasting systems use large quantities of abrasives. On some projects, vacuum recovery equipment is necessary. Many contractor customers will need large quantities of paint, blast nozzles, coupling gaskets, disposable outer lenses for respirator helmets, eye and hearing protection, hard hats, reflective vests and gloves.

Comments from the industry
Clemco Industries, Washington, Mo., Jeff Cleveland: "Rental companies can promote blast equipment to a wide range of construction trades. For big jobs, abrasive blasting can be more efficient than hand tools, power tools and chemical stripping. When contractors use blast equipment to strip paint from steel, new paint must be applied within hours to prevent rust. Blast equipment complements the rental company's arsenal of paint spray systems and fosters the sale of large quantities of paint."
Diamond Products, Elyria, Ohio, Chuck Markley: "Different parts of the country have differing concrete aggregates, so blades need segments with the right bonds to optimize cutting."
Equipment Development Co. (EDCO), Frederick, Md., Paul Gorgol: "When horizontal concrete has to be resurfaced, the first steps in the process are often the most critical. For long-lasting repairs, the underlying concrete must be prepared properly to enable overlays or coatings to bond securely."
MTA Distributors, Whites Creek, Tenn., David Harrington: "Rental customers should not encounter problems with concrete machines if they use them for applications they are designed for and follow instruction in manuals."
Sanders Saws, Honey Brook, Pa., Gary James: "For weekly and monthly rentals of concrete saws, customers will need to lubricate shaft bearings, monitor engine oil and perform other required maintenance. Damaged and worn blades need to be replaced."