On All Floors: Choosing the right surface preparation tools
Floor care takes up a considerable amount of time in most facilities. However, the less common task of floor repair and restoration often leaves building managers questioning where to start.
First of all, a manager should focus on three things: the type of coating to be removed; an economic way to remove and dispose of the coating materials; and ways to properly prepare the old surface for a new coating application.
It’s tough for most facility managers to know what type of coating material is on the building’s floors, when it was applied or who performed the work. For removal of surface coatings, there are now many successful processes available that can be utilized to meet most expectations. Because surface-coating removal can involve many unknown variables, it is impossible for one specific machine or process to address every problem.
Surface grinding equipment has been utilized for more than 40 years, with dual-head, counter-rotating units being the most popular. The original concept was to repair damage caused by improper concrete-pouring techniques or environmentally related factors, but a number of manufacturers have developed a greater variety of attachments to increase their functions.
For the past 30 years, the most popular attachment for surface grinders has been silicon carbide impregnated grinding stones, popular on concrete surfaces. Throughout the years, other attachments or processes were developed specifically for surface coating removal. Of these, only two types of attachments have earned an excellent track record: diamond systems and tungsten-carbide inserts. A diamond grinding system is favored for removing many thin film coatings or those coatings with hardness values that preclude the use of any other system. Coatings with a thickness greater than 0.10 inch can normally be removed more quickly with other attachment designs.
How does a building manager know if a diamond grinding system is the solution for a specific job application? The answer is to consult the various system manufacturers for their technical expertise. The general rule is that a diamond grinding system will always remove a surface coating. Besides higher productivity rates, a diamond grinding system normally exhibits a long service life that can approach 50,000 sq.-ft. for typical removal applications. The question then becomes a matter of production rates versus operating costs: is there an alternative that is even faster and less costly for the job? Depending on the specific application, there can be more productive alternatives.
Probably the most important attachments for coatings removal are tungsten carbide inserts. During operation, the insert edge must first penetrate the coating and then use a combination of applied weight and relative movement to scrape the coating away from the surface. To determine if such a system will work for a particular project, place the blunt edge of a standard file against the coating. Tilt the file so that the blunt edge makes a 15-degree angle with the surface and press down on the file handle and move back and forth. If the blunt edge begins to remove the coating, the tungsten-carbide insert system will probably be effective.
Surface-planing equipment is normally utilized to deliver a destructive action against both vertical and horizontal surfaces. The most common uses include removing traffic lines, milling misaligned concrete slabs and preparing floors for topcoat applications. The process implements a drum loaded with small flails of various configurations that are rotated at a relatively high speed. As the flails come in contact with the surface, their high energy is transferred into a destructive process that quickly removes the material.
There are four basic flail types: star flails produce a fine, broom-swept texture and work best for removing coatings and encrusted materials, cleaning concrete and asphalt surfaces or light scarification before applying a new surface coating; beam flails can handle thicker coating removal applications and work well removing traffic lines or performing medium-duty concrete or asphalt removal; tungsten-carbide-tipped flails are of higher quality and work best on heavy-duty concrete and asphalt removal or grooving projects as well as leveling uneven sidewalk tripping hazards; and milling flails operate in a “climb cut” mode, working best when the machine is pulled toward the operator. Use milling flails to remove membrane-type materials or traffic lines from concrete and asphalt.
Air Tools and Strippers
Long-reach air tools use a rapid, hammering action and can be used overhead or in tight spaces. They make short work of removing tile, coatings and adhesives in corners and can easily maneuver around obstructions and other hard-to-reach areas where use of larger equipment is not feasible. Air tools are not typically considered primary solutions for coatings removal projects, but instead they complement larger, mechanized surface preparation equipment.
Strippers, meanwhile, come with a variety of blades in a number of widths to tackle carpet, linoleum, vinyl composition tiles, ceramic tiles and more. Floor covering that has been applied in sheets, such as linoleum and carpet, will need to be sliced as it is removed so that it comes off in strips. This requires a scoring blade. Other accessories include various sizes of straight blades with beveled edges, ideal for removing vinyl and linoleum tiles, and mastic removal blades, which use a sharper angle to scrape way residue and film left behind by flooring and adhesive materials.
Use of pneumatically powered scabblers is normally reserved for removal of thick layers of concrete from floor and walls. Today’s scabbling products range from lightweight, single-piston handheld units to large, multi-piston units that are wheel-mounted to increase maneuverability.
With some experimentation and common sense, the resulting surface texture can actually aid the adhesion of a new top coating. As with long-reach air tools, scabblers work best as a complementary process to larger, mechanized surface preparation equipment. But in tight corners and restrictive areas on both vertical and horizontal surfaces, scabblers or air tools at times are the only practical solutions.
Dennis Von Ruden is the president of General Equipment Co. For more information, visit www.generalequip.com.