Q: Why do I need to use a primer instead of just using two coats of the finish paint?
A: A primer is beneficial because it helps provide a uniform surface that promotes good adhesion of the topcoat. A primer can also serve a special purpose by sealing a porous surface, blocking out stains, preventing rust formation on iron and steel, and preventing tannin bleed on wood. Most finish paints are designed to provide a decorative or protective finish for a substrate. In most situations, they do not provide the features of a primer, so it is always important to follow the manufacturer's recommended coating system.
Q: What is hatbanding and what causes it?
A: Hatbanding is a phenomenon that appears as a stripe at the edges or top of a wall. It occurs when the brushed "cut-in" area is dry when the wall is rolled. By not rolling onto a wet edge, the difference in the texture of the brushed paint and rolled paint becomes very visible. Hatbanding is corrected by applying another coat of paint, keeping a wet edge of cut-in areas.
Q: I do a lot of restoration work in old houses that I know have lead-based paint on the trim. What do you recommend for removing the paint and the lead hazard?
A: Nothing! Only trained and licensed lead removal contractors should handle lead removal. You will find this warning on all our cans of paint: Warning! Removal of old paint by sanding, scraping or other means may generate dust or fumes that contain lead. Exposure to lead dust or fumes may cause brain damage or other adverse health effects, especially in children or pregnant women. Controlling exposure to lead or other hazardous substances requires the use of proper protective equipment, such as a properly fitted respirator (NIOSH approved) and proper containment and cleanup. For more information, call (in the U.S.) the National Lead Information Center at 1-800-424-LEAD or contact your local health authority.
While the manufacturers of some chemical paint strippers recommend using their products for removing lead-based paint, you still have to comply with lead removal and hazardous waste disposal regulations. Be safe. Leave this work to specialists.
Q: What does saponification mean?
A. Saponification is the reaction of an alkaline surface, such as concrete or galvanizing, with the oils in a coating. This reaction forms a soap-like material at the coating/substrate interface and eventually causes the coating to peel.
Q: What causes fisheyes?
A: Fisheyes are caused by some type of surface contamination that was not removed in preparation for painting. This contamination can be from body oils, silicone from furniture polish, or any greasy or oil substance. The slippery deposit on the surface does not allow the paint to adhere, causing it to shrink away from the contamination and form a dimple-like void in the paint film.
Q: I see the term "Volume Solids" in most specifications. What does it mean, and why is it so important?
A: Paint is made up of four basic elements: solvent, binder, pigment and additives. The material left on a substrate after the solvent evaporates and the coating cures is its solids content. When calculated as a percentage of the total gallon of paint, the solids are referred to as "Volume Solids." A higher percentage of Volume Solids is usually an indication of a better quality paint because more binder and pigment are left to protect the surface compared to a coating with a lower Volume Solids rating.
Q: What types of cleaners can I use to remove mildew?
A: Try using a solution of one quart household beach in three quarts of water. Apply the solution to the area with mildew and then rinse off with water. Never add detergents or ammonia to the bleach/water solution. Always protect your skin and eyes against splashes.
Q: What's the best way to remove stains on redwood and cedar?
A: First determine the source of moisture that brought the stain to the surface and correct it. Next, remove the stain with a 50/50 solution of water and denatured alcohol. Allow the surface to dry completely, then apply an alkyd primer and topcoat to prevent stains from recurring.
Q: What effect does wiping vinegar on plaster walls have?
A: Wiping a mixture of one part vinegar and four parts water on a soft or powdery plaster wall hardens the plaster so that it will accept a paint film. After the plaster dries, prime it with PrepRite Masonry Primer or PrepRite Wall & Wood Primer and topcoat it with Duration Home® or Super Paint.
Q: How do I remove insects from fresh paint?
A: If bugs land on the wet paint, let them stay until the paint dries. Once dry, remove them with a clean paint brush. You might end up with small, unnoticeable "bug prints," but that's better than removing the bugs and trying to touch up partially dry paint. Using a faster-drying exterior-latex paint, like Sherwin-Williams SuperPaint, is helpful in this situation. Latex paint dries quicker than oil-based paints, giving insects less time to get stuck in the coating.
Q: How do I determine when a concrete floor is ready to paint?
A: New concrete should cure for at least 30 days. Check for moisture by taping a 2'x2' piece of 4-mil plastic to the floor with duct tape. If no darkening of the concrete or condensation is evident after 24 hours, the floor is dry enough to paint. The floor should be thoroughly cleaned and acid etched prior to application.
Q: What determines if a joint should be recaulked? Should old caulk always be removed?
A: If the old caulk is cracking or pulling away from the surface, dig it out and replace it. Prime the bare wood then re-caulk. Any butt joint in siding or other joints between two pieces of wood should be caulked. You DO NOT want to caulk the lap joints of siding since they allow moisture to get out from behind the wood.
Q: I need to paint a residential ceiling that has been stained from a previous water leak. I would like to know the best approach to sealing the stain before applying flat ceiling paint.
A: I suggest you take care of all the repair work first, then apply an alkyd primer-sealer, such as ProBlock, to seal out the water stains.
Q: I removed wallpaper from a paneled wall, however a residue of wallpaper paste remains. I want to leave the paneling as is - no paint or wallpaper over it. How do I remove the paste residue without harming the paneling?
A: Use a paste remover or vinegar and water.
Q: How can I cover and paint over a water-stained but otherwise undamaged ceiling?
A: After you have corrected the cause of the water staining, use a primer sealer designed for stain blocking, such as ProBlock Primer/Sealers. They are available in both alkyd and latex-based versions. While both work to block this type of stain, the alkyd stain blocker will usually seal water stains better because it doesn't contain water that could re-wet the stain. You may still see the stain through the stain blocker, but they are designed to "lock-in" the stain to prevent it from bleeding through into the topcoat.
Q: For interior doors and trim with glossy finishes, can I use a primer instead of sanding or scuffing the surface?
A: You want to use Adhesion Primer. You will still need to wash and clean the surface first.
Q: Can I apply latex paint over a surface finished with an oil-based product?
A: Yes you can. You have two choices to do this. First would be to wash the surface, sand and then clean the sanding dust off. You may then apply your latex paint over the oil base paint. That process works for both interior and exterior applications. Your other option is to wash the surface and then apply a coat of a adhesion primer and then topcoat.
Q: Can acrylic latex house paint be applied over gloss alkyd paint? Is special prep work necessary to ensure good adhesion?
A: Yes, to both questions. But, to ensure good adhesion, glossy surfaces must first be washed clean and then sanded to allow the paint to "grip" the surface. Gloss alkyd paints that are exposed to harsh weather conditions have a tendency to "chalk" - that is, the old paint film develops a faded, powdery substance on the surface. So it's best to wash off any excessive chalk prior to applying an acrylic topcoat. When painting bare surfaces, use an appropriate primer before applying the topcoat. This will ensure the best adhesion and long-term durability.
Q: What is the most efficient method for tackling calcimine painted surfaces like ceilings?
A: Since calcimine paints contain little or no binder, they tend to be very chalky. Clean the surface with a household cleaner to remove as much chalk as possible. Rinse thoroughly. Then apply a primer that secures adhesion on chalky surfaces, such as LOXON Conditioner. Follow with two coats of the topcoat of your choice.