Q: How do you tell what type of paint is on a surface? If paint is peeling, how do I find out if its oil or latex paint? If its brittle and brakes when you crunch, is this oil?
A: If the paint is at least several years old and is peeling, take a piece of it and bend it. If it cracks, it is most likely oil based or alkyd paint. If it seems flexible, it is probably latex. (However, highly pigmented economy latex paints can tend to crack when flexed this way.) If it is a combination of one type applied over the other, then the oil-based portion is more likely to crack, while the latex part would be more flexible. Another test would be to soak the piece of peeling paint in some acetone or fingernail polish remover. If it dissolves or significantly softens, then the peeled paint is likely to be latex. Be sure to use safe practices when working with acetone or fingernail polish. Protect your skin.
Q: What is the difference between paint thinner and solvent?
A: Solvent is a general term used for different organic liquids. Examples of some used with paints and coatings are lacquer thinner, paint thinner, naphtha, denatured alcohol, turpentine. Paint thinner is a specific solvent used with oil based paints, stains and varnishes. Paint thinner is made mainly from a solvent called mineral spirits. Paint thinner is similar to "lighter fluid" and "charcoal starter". Paint thinner is less flammable than lacquer thinner and gasoline.
Q: I have chipping, flaking paint on my very old garage doors. Can I power wash it without damaging the wood?
A: We suggest you not attempt power washing the wood doors. There is a good chance that the wood could be cut or otherwise damaged. Areas particularly vulnerable are sections exposed to the elements by peeling paint. Careful scraping of all loose paint or paint with marginal adhesion, followed by feather sanding of all exposed wood and all rough paint edges is, in order. If any of the remaining paint has dirt or chalk on it, scrub with a mild detergent, and rinse.
Q: I am getting ready to paint my house, but I have some rusty nails throughout the wood. How do I prevent rusting nails from staining or showing through?
A: If nails have rusted and stained the exterior wood in the past, they’ll do it again unless you guard against it. To prevent repeat rusting, sand the rusting nail heads, then sink them below the surface of the wood. Next, seal them with a sealer, a primer-sealer or a primer that contains rust inhibitors. Finally, fill in the dent with putty and surrounding wood to create a smooth, continuous surface.
Q: Why is the paint on my home's exterior fading?
A: When exterior paints aren’t capable of enduring the sun’s ultraviolet radiation, the unfortunate results are faded colors and a weak skin that allows damage to the building material underneath. Ultraviolet rays tend to deteriorate paint binders. The binder remains as part of the final paint film, holding the pigment particles in place. Most exterior paints contain resins that are naturally resistant to UV radiation. Look for an exterior paint that contains UV inhibitors or pigments that absorb or reflect the sun’s damaging rays and keep from reaching the substrate under the paint film.
Q: What are the ideal weather conditions for outdoor painting?
A: Most alkyds can be applied successfully within a temperature range of 40° F to 90° F. Latex will usually adhere and perform best if the temperature at the time of application is between 50° F and 85° F. A safe, general rule of thumb for both latex and alkyds is this: Ideal conditions include temperatures between 70° F and 85° F and relative humidity between 40% and 70%. However, make sure you read the directions on the product you plan to use to see if there are ideal weather conditions for application with that particular product.
Q: What is the relevance of VOC?
A: VOC refers to "volatile organic compound"; some examples are paint thinner, mineral spirits, alcohol, gasoline, ethylene glycol, acetone and xylol. Most architectural paints contain some VOCs. With oil-based products, the paint thinner is VOC. With shellac, the alcohol is VOC. With water-based, or latex, paints, the water is not a VOC, but some additives are, typically several per cent are VOC. Some latex paints on the market now are very low in VOC content. It is some of the VOCs that give latex paint the odor that it has, so these low-VOC paints are generally characterized is "low odor." The EPA is limiting the level of VOCs in paints, because when they evaporate into the air when the paint dries, they can contribute to low-level smog generation. Still, the amount of VOCs coming from coatings is extremely small as compared to that coming from auto and electric power emissions, and from pine trees. There is some sacrifice of paint properties when going to no-VOC formulations, but the performance is generally considered satisfactory.
Q: Which method is better for applying outdoor paint -- brush or spray?
A: Basically, both spraying and brushing are fine, so long as the paint is put on at the proper spread rate (sq. ft./gallon). Spraying will provide a smoother appearance, and less chance for mildew to get into brush marks and grow. With spraying, the painter has to be careful about getting a full coat onto areas that are next to areas that won't be painted, so careful masking must be done. Some people think sprayed paint will not adhere as well as if brushed, but as long as the surface has been properly prepared that should not occur.
Q: My house is old and the shakes are very dark from age. I want to make my house a lighter color. The painter said we should use stain but he doesn't think stain will get it light enough. I asked if we can use paint with a primer he said if we did it would not last. Is there a product or a process that will give the desired result and still have a lasting effect?
A: The darkness of the shakes is probably due to a combination of tannins concentrating on the surface, and mildew growth. (There also may be old stain contributing to the darkness.) So, in painting the shakes, the mildew should be treated first: apply a 3:1 mixture of water:household bleach, and allow it to remain on for about 20 minutes, adding more as it dries. It makes sense to do a section at a time, say 25 square feet.
After the 20 minutes, the surface should be rinsed by flushing with water. (Power washing with water is best avoided with old cedar shakes, as it can damage the wood). Then the surface should be refreshed using a hand or power brush. The brushing action should be vertically downward, and done enough to remove the top layer of weathered wood fibers.
Then an exterior stain-blocking wood primer should be applied. Options are: an oil-based primer or a latex primer. You and your painter will have to decide which approach to take. The oil-based type will have better stain-blocking capability for severely-staining shakes, but the latex primer will provide better long-term crack resistance, mildew resistance and general durability.
Applying two coats of latex primer will enhance stain blocking as well as crack resistance and mildew resistance. A quality latex paint can be applied to either type primer. An oil-based paint should be applied only to the oil-based primer. If you go with the latex primer, it is best to apply it only if the shakes are thoroughly dried out and the humidity is not particularly high, and not when it will rain within the next day or so.
Do not apply the primer in bright, direct sunshine. With the latex type primer, assuming two coats are applied, allow an overnight dry between coats. For the paint itself, we recommend using a top of the line exterior 100% acrylic latex house and trim paint in a flat or satin finish. Two coats will provide maximum mildew resistance, crack resistance and general longevity.
Q: What does the term "epoxy" mean? How does it apply to paint as opposed to glue or cement ?
A: In general terms, an epoxy polymer is a tough plastic-like material made by reacting a compound with the expoxide group (R1-HC[O]CH-R2) with an amine, alcohol, organic acid, an unsaturated compound, etc. These are employed to make tough, chemical and water resistant adhesives, patching materials, insulating materials, auto finishes, and paints, especially for interior commercial and industrial wall and floor surfaces. Most epoxy patching compounds, adhesives, sealers and paints are prepared by combining two components on-site, just before application. Some epoxy materials are very high or 100% solids; some are two-component water-based acrylic-epoxy; and some are one-package water-based products. Two-component epoxy systems generally do not stand up and maintain color in exterior applications as well as two component urethane systems.
Q: Can a quality latex paint be hurt if it has been frozen and thawed?
A: Yes, latex paint can be hurt if it is frozen. Problems that can occur are reduced gloss, separation of ingredients, formation of "grit" or lumps. Often, though, a paint may survive one or a few freeze-thaw cycles. If a paint is frozen, it should be thawed slowly; then thoroughly stir the paint. If it appears to be smooth and of normal consistency and of the proper color, it probably is OK to use.
Q: As I continue my lifelong mission of cleaning out my basement, I'm finding several half-used cans of latex paint. Do you have any suggestions on what to do with them?
A: How about turning those cans of leftover paint into cans of primer? Just add E-B Emulsa Bond and you have a primer that will make paint stick to chalky, dusty and porous surfaces. This includes aluminum siding, hardboard siding and weathered masonry.
Q: What is a paint conditioner?
A: A paint conditioner is an ingredient added to paint when surface or weather conditions prevent the paint from performing as it was formulated. The conditioner helps the paint to overcome the negative situation. Often surface conditions such as excessive chalk and high porosity or weather conditions such as cold or hot temperatures, low humidity, etc. challenge the performance of a coating that was formulated to perform satisfactorily under average conditions. Thinner and water evaporate when containers are left open in hot, dry weather, causing the paint to drag. Cold weather turns paint sluggish, and again, it resists best efforts to apply a smooth coating. When the substrate is dry and porous it will suck the solvent from the paint and cause improper film formation. Most latex paints don't wet chalk or dust as well as oils do, and adhesion can be poor at best. The right paint conditioner can help overcome these problems and can also help you produce a more professional-looking job at the same time.
Q: What does "hiding" mean?
A: Hiding is the ability of paint or coating to mask or cover the surface.
Q: Why do light colors often hide better than darker ones?
A: Colors mixed in pastel and midtone bases have more titanium dioxide (TiO2) than those mixed in deep bases, and it's primarily the Titanium that provides surface hiding.
Q: When is a roller better to use than a paintbrush?
A: Use a roller where possible when painting larger areas, as this will provide a much more even finish and will also be quicker than a brush. Where a roller may be unsuitable, use a 4-inch or 6-inch emulsion brush. Brush and roller extension poles are available to assist painting ceilings and high walls. Paintbrush sizes 1/2-inch to 4-inches can be used to paint gloss on to wood surfaces. To speed up the painting of doorframes, window frames and skirting, low tack masking tape can be used to protect the surrounding painted areas. When finished, don't forget to wash out brushes and roller so they are ready for the next time.