MORE ABOUT PAINTS AND STAINS - PART TWO
This is part 2 of a 2 part series of articles on paints and stains.
Finally, Interior Paints Coatings for Each Job
Do you ever wonder about the difference between interior and exterior paints? I once used exterior paint on an inside ceiling, reasoning that it could last longer. It could last longer, but as I then found out when I was required to touch up the ceiling only 2 years later, exterior paints will discolor on an inside surface. Exterior paints contain special additives made to withstand the outdoors. Interior paints have additives that help the paint dry to a durable, uniform surface finish.
Most of the advances in painting technology have been with latex. Actually, latex has overtaken oil-based paint in several areas: strength and elasticity, as well as ease of application, clean-up, and disposal. Latexes have fewer VOCs than oil-based paints. Some, like the Pristine brand created by Benjamin Moore, are made with no VOCs whatsoever. Today's latexes are made with top quality pigments and binders that provide them more body, so they go on thicker.
Latexes enjoy quite a lttle bit of attractiveness for interior applications, specifically for walls and ceilings. Alkyds remain the professionals' choice for trim work because oil based paints are simpler to paint on detailed surfaces like molding and trim. However, that traditional approach is slowly changing as better latexes, including Pratt & Lambert's Accolade Interior Acrylic Semi Gloss, are introduced to the market.
High Demand Exterior Paint Coatings
Moisture is an important concern for exterior paint selection. Every day a family group of four will create several gallons of vaporized water in the house.
Combined with naturally occurring humidity, this may mean a lot of moisture moving through the walls and siding. Dampness is highest in the baths and kitchen. If these rooms aren't sufficiently ventilated, water will migrate through the wall surfaces. Vapor barriers help contain wetness, but vapor always seeks to escape. The structure of a home, the type of vapor barrier they have, ventilation, and dampness all make selecting the right paint critical.
In wetter climates you need a paint that will let moisture go through the wood, so water doesn't get trapped under the paint and cause blistering and peeling. Latexes are porous and let moisture pass through, unlike alkyd paints, which form a waterproof seal. Alkyds also don't flex with areas that expand and contract, as wood will, especially in colder climates. Latex paints have significantly more elasticity, allowing better adhesion.
I favor using latex on most exterior areas, including wood siding, stucco, and masonry. Latexes avoid fading better than most oil-based paints, and they'll cover either oil-based or latex primer (most oils have to go over an alkyd primer).
Latexes perform a great job of covering cement. Despite its hardness, concrete is very porous, and oil-based paints don't always adhere well. For ideal durability, I would recommend latex enamel.
In general, if I know of a latex product that provides superior performance, I will choose it over an oil-based product that needs to be cleaned with a thinner.
Latex only requires water. Thinners add yet another expense, are hard to get rid of, and usually finish up spattered on my skin or clothes, no matter how careful I am.
Solution For Staining Inside
You can spend a life learning about stains and sealers, but there is nothing mysterious about them. The bottom line in determining which stain to utilize is to familiarize yourself with the product lines available. Read the label, along with any product information you can get, and speak to the staff at a professional paint shop.
Exterior stains come in oil based, varnish, polyurethane, and water-borne solvents. Stains have less colorant than paint and more solvents, giving them increased wood penetration. Waterproofing is a priority with exterior stains. Most come with built-in sealants to add durability and help preserve the wood. The colouring in stains can be pigments, dyes, or both. A semi-transparent stain has more dye for grain penetration. A solid stain has more pigment for surface covering. Pigment is a finely ground coloring that doesn't penetrate the grain as deeply as a dye. That's why a pigmented stain is always accompanied by a sealer such as urethane or varnish.
Some high quality interior stains have dyes to penetrate and pigments to bring out the richness of the grain. Others contain only pigments, which are better to apply, combine, and touch up. Pigmented stains are lighter in color and draw out more of the wood grain. If you're looking for darker results, a dyed stain provides what you would like in one overcoat (be sure to use a conditioner on porous wood, such as pine and birch wood, to avoid splotching). Dyed stains are almost impossible to touch up. Every coating eventually will need touching up, so be sure to consider ease of maintenance in your choice of stains. You'll receive the best results by using better stains such as Minwax, Pratt & Lambert's Tonetic, Pittsburgh's Rez, or Wood-Kote.
If you wish to avoid the watery nature of stains, get a gel stain, which has had almost all of the water solvent removed. Gels are easy to use. They spread on, dry out fast, and cover evenly. Because they're colored with pigment, gel stains don't penetrate that well. They're a good choice for porous woods that are difficult to coat evenly with out a toner. Gel stains do a excellent job of bringing out the grain on embossed metal or composite surfaces. I don't recommend using them for hardwoods, which need a good dye stain to emphasize the depth and beauty of the grain.
No-Fuss Painting Using Sanding Sealers
Sanding sealers are interior primers that both penetrate and seal wood. You can use them under clear coats or over stains as sealers. Sanding sealers are different from a sealer like polyurethane, which is not designed to prime. They're more like varnish, but diluted with solvents to allow better penetration for priming. The hardness of varnishes and lacquers inhibits them from soaking in to the wood pores. Sanding sealer provides a better bond for clear coats.
Shellacs are often put into sanding sealers to fortify the resin and offer a quick drying agent. In addition they add an amber tone, so if you are utilizing a sanding sealer with shellac, make sure it won't influence the stain. Shellacs tend to yellow aver time and contain toluene, that has a high VOC content. Shellacs are gradually offering ways to new sanding sealer formulas with lower VOCs and better performance.
Alkyd resin sanding sealers likewise have high VOCs, although less than their shellac based cousins. Pittsburgh Paints makes a slow dry alkyd resin sanding sealer without shellac known as Rez 77-1. This particular primer/sealer is good for both interiors and exteriors. Pratt & Lambert's Latex Sanding Sealer has suprisingly low VOCs, but is only for interior wood and must not be used under a water based polyurethane.
Oil-based sanding sealers can also be used to seal outside wood, especially decking, which is constantly subjected to sun and water. For color consistency in areas like decks, you need to completely coat, or back prime, the lumber before it goes up, using the same sealer or stain. Olympic Water Guard, Messmer's UV Plus, Behr's, and most top quality deck stains are great water repellent sealers that can also be used for priming exterior wood.
Wood and Stain Sealers Solution for Interior Wood
Sealers, including varnishes, lacquers, urethanes, and shellacs, are put into the stain itself, applied as a top coat over a stain, or used as a clear coating on unstained wood trim. They can be used for just about any type of wood trim, including windows, doors, and the casing around them. Although you can buy stain/sealer combinations, they tend to yellow, are difficult to keep up, and don't endure as long as separately applied stain and sealers.
Varnishes contain natural oils such as Tung oil, an extremely hard, durable sealant that may be brushed on and dries slowly. Varnishes are easy to clean and maintain with soap and water followed by a wiped on varnish, which often keeps a wood surface looking great for years. Make certain there's no wax in your cleaner, because wax clogs wood pores. I favor to work with Hope's Tung Oil varnish for a wipe-on maintenance layer. Lacquer is a quick dry sealer that more often than not needs to be sprayed, since it becomes tacky almost immediately.
Polyurethanes do almost everything shellac does, but they're much easier to maintain. While shellacs act like paint, polyurethanes act more like a clear coating that permeates the wood instead of resting on it. Polyurethanes brush on and dry out quickly, with little odor and VOCs. They have more or less replaced shellacs as a clear sealer. Another reason urethanes have become such popular sealers is the fact they don't require sanding sealers.
The smells associated numerous paints and stains can be more than simply offensive, they can be toxic. Solvent based varnishes, lacquers, and shellacs give a very hard finish but contain very high VOC levels. Water based sealers, like the stains, match the performance of several solvent based sealers, with fewer VOCs. The VOC content of water borne sealers such as Sherwin Williams Kern Aqua Lacquer average about 250 grams per liter, or 2 pounds per gallon, half the most common VOCs of oil-based lacquers. The ethers in water borne sealers aren't combustible, another advantage, but they still have sufficient VOCs to warrant a respirator.
Although they resist yellowing, water borne sealers such as acrylic latex polyurethanes do tend to raise the grain. They'll also harden or "flash off" quickly at temperatures higher than 60°F. The best working temperature for nearly all water borne acrylic latex polyurethanes is between 50°F and 60°F, which lets them flash a bit more slowly. In this case, flashing-off simply means that the solvent evaporates and leaves the resins to finish the drying process. A contractor I knew once used water based latex polyurethane sealer that flashed off so fast he could only apply it between 5 A.M. and 9 A.M. Anything later than that was too warm.
Minwax makes very good water based polyurethane, as do Pittsburgh, Pratt & Lambert, Benjamin Moore, as well as others.
Stains and Sealers for Exterior Applications
Because of their better penetration and sealing power, most exterior stains sold today are oil-based. However, oil-based solid stains peel as they grow older, making them more difficult to maintain. A solid stain is like paint: It coats more than it penetrates. A latex solid stain peels less and is also simpler to maintain as it ages. However, I prefer oil-based products for semi-transparent stains. Added oil solvents let them penetrate deeper. A number of the better stains on the marketplace include Pittsburgh Solid Color Latex Stain, Messmer's U.V Plus, Moorwood Solid Color Exterior Stain, Sherwin Williams Woodscape stains, Pittsburgh Semi-transparent Exterior Stain, Rez Deck Stain by Pittsburgh, and the Sikkens Cetol system.
Deck stains usually have more solids than a typical exterior stain, which will make them stronger. I would recommend buying a high-end stain that is semi-transparent or what's called a trans-oxide. Until lately, the significant problem with outdoor stains was their low UV resistance, but newer trans-oxides have finely ground metal mixed in for better protection. A higher end deck stain won't require a different sealer overcoat, although you can add one (such as Olympic Water Guard) if you believe extra protection is needed to battle water and sun exposure. Better deck stains retail for approximately $35 a gallon and cover 300 to 400 sq. ft.
Stay away from deck stains which contain silicone. Despite their attractive price, they aren't a good deal. Advertisements for silicone stains and deck sealers often show beaded up water on the deck, and many people are fooled into thinking that this is the indication of an effective coating. However, silicone breaks down quickly, usually in just a matter of months, producing a discolored, waxy coat that is clearly a pain to remove. The broken down silicone also quits repelling water.
"High build" coatings such as Sikkens and Messmers work remarkably well on exterior siding, however they are too soft to be utilized on your deck. Eliminating these coatings calls for gallons of wood cleaner and a significant amount of work.
Water borne exterior stains, such as Sherwin Williams Woodscapes, combine the features of oil-based and latex coatings. They run and drip significantly less than oil based stain, and dry faster, enabling two coatings the same day. Water borne stains possess the resilience and versatility of a latex stain, giving them stamina. They're a great choice for some applications. But bear in mind that clearing up water based stains will take work. You will find a couple of oil components in the solvent which have to be cleaned. First use soap and water, then alcohol. Ask your dealer for specific cleaning guidelines for water based stains, and read the label.
When In Doubt, Ask
If you still have questions about which paint or stain to make use of, don't hesitate to ask people in the know. An experienced, proficient salesperson can answer any questions it's likely you have. Choose a paint store with personnel having at least 10 years of experience in the business. Inquire further what has worked best for your unique application and ask to see a spec sheet on the merchandise in question.
The answers you get will rely upon whom you ask. A paint store will try to market you one of their products, in the end, that's why they're in business. Painting contractors may not be impartial, either. They need to sell their experience. I get a lot of cell phone calls from people hoping for aid with their painting problems. Most painters, including myself, don't object to giving one hour of time, but if you need in depth answers, consider hiring a contractor for a professional evaluation. Rates vary, but I usually charge about $60 for a written and oral evaluation, depending on the driving time involved. A paid evaluation will let you know whether you should paint, stain, or re-side, as well as which coating might be best for your project. Each painting job has unique conditions that require specific answers.
Sound Quality Painting
824 90th Dr SE suite B
Lake Stevens WA 98258
(425) 512-7400
