This is part two of a 2 part series of articles on paints and stains.
Take The Headache Out of Finding Interior Paints Coatings for Each and Every 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 two years later, exterior paints will discolor on an interior surface. Exterior paints contain special additives made to withstand the outside. 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. In fact, latex has overtaken oil-based paint in several areas: strength and elasticity, as well as ease of use, clean-up, and disposal. Latexes have fewer VOCs than oil-based paints. Some, such as the Pristine collection made by Benjamin Moore, are created with no VOCs whatsoever. Today's latexes are created with top quality pigments and binders that provide them more body, so each goes on thicker.
Latexes enjoy quite a bit of attractiveness for interior applications, especially for walls and ceilings. Alkyds stay the professionals' choice for trimming work because oil based paints are much easier to paint on detailed areas like molding and trim. However, that traditional school of thought is gradually changing as better latexes, including Pratt & Lambert's Accolade Interior Acrylic Semi Gloss, come on the market.
Exterior Paints Coatings for Every Job
Moisture is an important concern for exterior paint selection. Every day a family group of four will create several gallons of vaporized water inside a house.
Combined with naturally occurring humidity, this may mean a a large amount of moisture moving through the surfaces and siding. Dampness is highest in the baths and kitchen. If these rooms aren't sufficiently ventilated, moisture will migrate through the wall surfaces. Vapor barriers help contain wetness, but vapor always seeks to leave. The structure of a residence, the sort of vapor barrier it has, ventilation, and dampness all make selecting the right paint critical.
In wetter climates you need a paint that will let moisture pass through the wood, so water doesn't get trapped under the paint and cause blistering and peeling. Latexes are porous and let moisture go through, unlike alkyd paints, which form a waterproof seal. Alkyds also don't flex with areas that expand and shrink, as wood will, especially in colder climates. Latex paints have more elasticity, allowing better adhesion.
I favor using latex on all exterior areas, including wood siding, stucco, and concrete. Latexes withstand fading much 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 do 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 will provide superior performance, I'll choose it over an oil-based product that should be cleaned with a thinner.
Latex only needs water. Thinners add one more expenditure, are hard to dispose of, and usually end up spattered on my skin or clothes, regardless of how careful I am.
Solution For Staining Inside
You could spend a life time learning about stains and sealers, but there is nothing mysterious about them. The bottom line in figuring out which stain to make use of is to become acquainted with the product lines available. Scan 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 much more solvents, providing them with greater wood penetration. Waterproofing is important with exterior stains. Most come with built-in sealants to add toughness and help preserve the wood. The coloring 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 definitely used along with 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, blend, and touch up. Pigmented stains are lighter in color and draw out more of the wood grain. If you are looking for darker results, a dyed stain will provide what you want in one overcoat (make sure to use a conditioner on porous wood, such as pine and birch wood, to avoid splotching). Dyed stains are extremely difficult to touch up. Every coating eventually will need touching up, so make certain to consider the ease of maintenance in your selection of stains. You'll get 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, try a gel stain, which had almost all of the liquid solvent removed. Gels are simple 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 challenging 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 working with them for hardwoods, which require a good dye stain to emphasize the depth and beauty of the grain.
How We Improved Our Painting With Sanding Sealers
Sanding sealers are interior primers that both penetrate and seal wood. You can use them under clear coats or on top of 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 into the wood pores. Sanding sealer can provide a better bond for clear coats.
Shellacs are often put into sanding sealers to strengthen the resin and provide a quick drying agent. They also add an amber tone, so if you're by using a sanding sealer with shellac, make sure it will not have an effect on the stain. Shellacs have a tendency to yellow aver time and contain toluene, that has a very high VOC content. Shellacs are slowly 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 drying 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 very low VOCs, but is only for interior wood and shouldn't be used under a water borne polyurethane.
Oil-based sanding sealers also can be utilized to seal outside wood, especially decking, which is continually subjected to sun and water. For color uniformity in areas like decks, you need to completely coat, or back prime, the wood before it goes up, using the same sealer or stain. Olympic Water Guard, Messmer's UV Plus, Behr's, & most high end deck stains are excellent water repellent sealers that also can be utilized for priming outdoor wood.
Wood and Stain Sealers for Interior Wood – Safely
Sealers, including varnishes, lacquers, urethanes, and shellacs, are put into the stain itself, applied as a top coat on top of a stain, or used as a clear coating on unstained wood trim. They can be used for just about any type of trim, including windows, doors, and the casing around them. Although you can purchase stain/sealer combinations, they have a tendency to yellow, are difficult to keep up, and don't last as long as separately applied stain and sealers.
Varnishes contain natural oils such as Tung oil, a very hard, durable sealant that may be brushed on and dries slowly. Varnishes are easy to clean and keep maintaining with soap and water accompanied by a wiped on varnish, which often keeps a wood surface looking great for years. Make sure there is no wax in your cleaner, because wax clogs wood pores. I prefer using Hope's Tung Oil varnish for a wipe-on maintenance layer. Lacquer is a quick drying sealer that almost always needs to be sprayed, since it becomes tacky almost immediately.
Polyurethanes do almost everything shellac can do, but they're simpler to maintain. While shellacs act like paint, polyurethanes act more like a clear coating that permeates the wood instead of sitting on top of it. Polyurethanes brush on and dry out quickly, with little odour and VOCs. They have more or less replaced shellacs as a clear sealer. Another reason urethanes have grown to be such popular sealers is the fact they don't really require sanding sealers.
The smells associated with many paints and stains can become more than just offensive, they can be toxic. Solvent based varnishes, lacquers, and shellacs give a super hard finish but contain very high VOC levels. Water borne sealers, like the stains, match the performance of many 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 usual VOCs of oil-based lacquers. The ethers in water borne sealers aren't combustible, another advantage, but they still have enough VOCs to warrant a respirator.
Although they resist yellowing, water borne sealers such as acrylic latex polyurethanes do have a tendency to raise the grain. They will also set up or "flash off" quickly at temps greater than 60°F. The very best working temperature for nearly all water borne acrylic latex polyurethanes is between 50°F and 60°F, which lets them flash a little more slowly. In this case, flashing-off simply means that the solvent evaporates and leaves the resins to finish the drying out process. A contractor I know once used water based latex polyurethane sealer that flashed off so fast he could only use 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, and others.
Stains and Sealers for Exterior Applications
Due to their better penetration and sealing ability, most exterior stains sold today are oil-based. However, oil-based solid stains peel as they grow older, making them more challenging to maintain. A solid stain is like paint: It coats more than it penetrates. A latex solid stain peels less which is easier to maintain as it ages. However, I prefer oil-based products for semi-transparent stains. Added oil solvents let them penetrate deeper. Some 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 outside stain, which will make them stronger. I recommend buying a high-end stain that is semi-transparent or what is called a trans-oxide. Until lately, the major problem with exterior stains was their low UV resistance, but newer trans-oxides have finely ground metal mixed in for greater protection. A high end deck stain won't require a different sealer overcoat, although you can include one (such as Olympic Water Guard) if you think extra protection is required to combat moisture content and sun exposure. Better deck stains retail for about $35 a gallon and cover 300 to 400 sq. ft.
Avoid using deck stains that contain silicone. Despite their low price, they are not a good deal. Advertisements for silicone stains and deck sealers often show beaded up water over a deck, and many people are fooled into thinking that this is the indication of an effective coating. However, silicon breaks down quickly, usually in a matter of months, producing a discolored, waxy coat that is a pain to eliminate. The broken down silicone also stops repelling water.
"High build" coatings such as Sikkens and Messmers work remarkably well on outside siding, however they are too soft to be used on your deck. Stripping these coatings takes gallons of wood cleaner and a significant amount of work.
Water borne exterior stains, such as Sherwin Williams Woodscapes, incorporate the advantages of oil-based and latex coatings. They run and drip less than oil based stain, and dry faster, enabling two coatings the same day. Water based stains have the resilience and flexibility of a latex stain, giving them lasting strength. They're a great choice for some applications. However that clearing up water borne stains calls for work. You will discover a couple of oil components in the solvent which have to be cleaned. First use soap and water, then alcohol. Ask your supplier for specific cleaning guidelines for water based stains, and scan the label.
When In Doubt, Ask Questions
In the event that you still have questions about which paint or stain to utilize, don't hesitate to ask people in the know. An experienced, experienced salesperson can clear up any questions you might have. Look for a paint store with personnel having at least 10 years of experience in the business. Ask them 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 be based upon whom you ask. A paint store will try to sell you one of their products, after all, that is why they're in business. Painting contractors may not be impartial, either. They need to sell their knowledge. I get tons of cell phone calls from people wanting assistance with their painting problems. Most painters, including myself, don't mind giving one hour of our time, but if you need comprehensive answers, consider hiring a contractor for a professional evaluation. Rates vary, but I charge about $60 for a written and oral examination, with respect to the traveling time included. A paid examination will tell you 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 warrant specific answers.
Sound Quality Painting
824 90th Dr SE suite B
Lake Stevens WA 98258
(425) 512-7400
