Concrete Floors: Select the finish coat prior to preparing any concrete floor for painting. Select a finish coat appropriate for the intended use of the floor. Different types of finishes require different surface preparation. Moisture content should not exceed 12%. Perform a moisture test by taping plastic sheeting to the floor. Leave it overnight and check it for condensation in the morning. If moisture is present, contact your Farrell-Calhoun representative. Moisture in concrete may cause excessive internal vapor pressure, which in turn may cause blistering and peeling of paint. Another test is to perform a splash test where you splash some water onto the concrete to see if it soaks in or if it balls up. This test will let you know if a sealer is already on the floor or not.
Remove all dirt, dust, grease, oil, laitance, curing or hardener compounds and other contamination prior to coating by solvent cleaning, acid etching, scarifying, water blasting or sandblasting. The floor should be dry, and neutral or slightly alkaline (pH=7-8) prior to paint application. If solvent-based coatings are used, ventilation should be adequate to draw off the solvent vapors, which are heavier than air. Accumulation of these vapors could cause explosion and/or health hazards.
Generally, for foot traffic areas, wear resistance is the key factor. Polyurethanes have the best wear resistance, followed by catalyzed epoxies, chlorinated rubbers, and others. For steel-wheeled traffic, heavy, monolithic, silica-filled, or catalyzed epoxies should be used.
Please consult the Surface Preparation Information for more detailed instructions.
Wood Floors: Interior stained and naturally finished woods are normally hard woods due to their defined grain pattern and stability. Some soft woods are also used for these applications; however, special surface preparation may be required.
When finishing any type wood with a stain or natural finish, solvent wash the surface to remove oil, grease, wax, dirt and other surface contaminants. Oil is often deposited on wood by handling. These oils will greatly affect the absorption rate of stain, causing a blotchy finish. Always solvent wash the wood and use care when handling cleaned wood. After solvent washing, sand any surface irregularities. Never sand wood prior to solvent cleaning as this will drive oils into the wood grain causing uneven stain penetration. Sand only in the direction of the wood grain. Sanding across the grain will scratch the wood and show sanding marks when stained. Fill nail holes and other defects with a wood filler which will accept stain, or use pigmented wood filler. When an unstained or natural finish wood is desired, fill nail holes and other defects after application of the sealer coat. This will prevent the oils in the fillers from being drawn into the wood, and may greatly reduce the shrinkage of the filler.