This is part two of a 2 part series of articles on paints and stains.
Interior Paints Coatings for Every Job
Did you ever wonder about the difference between interior and exterior paints? I once used exterior paint on an indoor ceiling, reasoning that it would last longer. It could endure longer, but as I then found out when I had to touch up the ceiling only 2 years later, exterior paints will discolor on an inside surface. Exterior paints contain special additives designed 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. In fact, latex has overtaken oil-based paint in several areas: durability and elasticity, as well as ease of application, clean-up, and disposal. Latexes have fewer VOCs than oil-based paints. Some, including the Pristine series made by Benjamin Moore, are created without VOCs in any way. Today's latexes are made with higher quality pigments and binders that provide them more body, so each goes on thicker.
Latexes enjoy quite a lttle bit of attractiveness for interior applications, especially for walls and ceilings. Alkyds remain the professionals' choice for trimming work because oil based paints are better to paint on detailed areas like molding and hardwood 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.
Take The Headache Out of Finding Exterior Paint Coatings
Moisture can be an important concern for exterior paint selection. Every day a family group of four will create several gallons of vaporized water inside a house.
Coupled with naturally occurring humidity, this can mean a lot of moisture moving through the walls and siding. Moisture is highest in the baths and kitchen. If these rooms aren't sufficiently ventilated, moisture will migrate through the wall space. Vapor barriers help to contain wetness, but vapor always seeks to leave. The structure of a home, the kind of vapor barrier it has, ventilation, and humidity all make selecting the right paint critical.
In wetter climates you require 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 pass through, unlike alkyd paints, which form a waterproof seal. Alkyds also don't flex with floors that expand and shrink, as wood will, especially in colder climates. Latex paints have more elasticity, allowing better adhesion.
I favor using latex on most exterior surface areas, including wood siding, stucco, and masonry. Latexes withstand fading better than most oil-based paints, and they will 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 stay well. For ideal durability, I 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 needs water. Thinners add one more expense, are hard to get rid of, and usually end up spattered on my skin or clothes, regardless of how careful I am.
How to Stain Interior Surfaces
You could spend a life time learning about stains and sealers, but there's nothing mysterious about them. The bottom line in figuring out which stain to utilize is to familiarize yourself with the products available. Read the label, along with any product information you can get, and speak to the staff at a professional paint shop.
Outside 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 include built-in sealants to increase durability and help protect 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 is why a pigmented stain is often 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, that are better to apply, mix, 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 provides what you want in one layer (be 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 ease of maintenance in your choice 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 want to stay away from the watery nature of stains, try a gel stain, which has had most of the liquid solvent removed. Gels are easy to use. They spread on, dry out fast, and cover evenly. Since 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 without a toner. Gel stains do a excellent job of showing off 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.
Learn How to Use Sanding Sealers
Sanding sealers are interior primers that both penetrate and seal wood. You should use them under clear coats or on top of stains as sealers. Sanding sealers are different from a sealer like polyurethane, which is not made to prime. They're similar to varnish, but diluted with solvents to allow better penetration for priming. The hardness of varnishes and lacquers helps prevent them from soaking into the wood pores. Sanding sealer can offer a better bond for clear coats.
Shellacs are often put into sanding sealers to fortify the resin and provide a quick drying agent. In addition they add an amber tone, so if you're using a sanding sealer with shellac, make sure it won't affect the stain. Shellacs tend to yellow aver time and contain toluene, that has a very high VOC content. Shellacs are slowly providing ways to new sanding sealer formulas with lower VOCs and better performance.
Alkyd resin sanding sealers likewise have high VOCs, although significantly less than their shellac based cousins. Pittsburgh Paints makes a slow drying out alkyd resin sanding sealer without shellac known as Rez 77-1. This specific primer/sealer is good for both interiors and exteriors. Pratt & Lambert's Latex Sanding Sealer has very low VOCs, but is purely for interior wood and shouldn't be used under a water borne polyurethane.
Oil-based sanding sealers can also be used to seal exterior 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 great water repellent sealers that also can be utilized for priming outdoor wood.
Method for Wood and Stain Sealers on Interior Wood
Sealers, including varnishes, lacquers, urethanes, and shellacs, are added to the stain itself, applied as a top coat over a stain, or used as a clear coat on unstained wood trim. They could be used for any type of wood trim, including windows, doors, and the casing around them. Although you can buy stain/sealer combinations, they have a tendency to yellow, are difficult to maintain, 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 completely clean and maintain with soap and water accompanied by a wiped on varnish, which often keeps a wood surface looking great for years. Make sure there's no wax in your cleaner, because wax clogs wood pores. I prefer using Hope's Tung Oil varnish for a wipe-on maintenance coat. Lacquer is a fast dry sealer that almost always must 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 coat that permeates the wood instead of resting on top of it. Polyurethanes brush on and dry quickly, with little stench and VOCs. They have more or less replaced shellacs as a clear sealer. Another reason urethanes have grown to be such popular sealers is that they don't really require sanding sealers.
The odors associated with many paints and stains can be more than just offensive, they can be toxic. Solvent based varnishes, lacquers, and shellacs provide a very hard finish but contain very high VOC levels. Water based sealers, like the stains, match the performance of many solvent based sealers, with fewer VOCs. The VOC content of water based 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 based 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 have a tendency to raise the grain. They will also set up or "flash off" quickly at temperatures greater than 60°F. The best working temperature for most water borne acrylic latex polyurethanes is between 50°F and 60°F, which lets them flash a little more slowly. In cases like this, 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 ability, most exterior stains sold today are oil-based. However, oil-based solid stains peel off as they get 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 it is easier to maintain as it ages. However, I favor 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 outside stain, which will make them more durable. I would recommend buying a high-end stain that is semi-transparent or what is 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 greater protection. A higher end deck stain won't require a separate sealer coat, although you can add one (such as Olympic Water Guard) if you think extra protection is needed to combat moisture and sun exposure. Better deck stains retail for about $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 silicon stains and deck sealers often show beaded up water on a deck, and many people are fooled into thinking that this is actually the indication of an effective coating. However, silicone deteriorates quickly, usually in just a matter of months, leaving a discolored, waxy coat that is clearly a pain to remove. The broken down silicone also ceases 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 will take gallons of wood cleaner and a significant amount of work.
Water borne outside stains, such as Sherwin Williams Woodscapes, combine the features of oil-based and latex coatings. They run and drip less than oil based stain, and dry out faster, enabling two coatings the same day. Water borne stains have the resilience and overall flexibility of your latex stain, giving them lasting strength. They're a great choice for some applications. But bear in mind that clearing up water based stains can take 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 dealer for specific cleaning guidelines for water based stains, and scan the label.
When In Doubt, Ask
In the event that you still have questions about which paint or stain to work with, please ask people in the know. An experienced, proficient salesperson can answer any questions it's likely you have. Choose a paint store with staff having at least a decade of experience in the business. Ask them what has worked best for your particular application and ask to read a spec sheet on the product in question.
The answers you get will rely upon whom you ask. A paint store will try to sell you one of their products, in the end, that's why they're running a business. Painting contractors may not be impartial, either. They need to sell their knowledge. I get tons of cell phone calls from people seeking assistance with their painting problems. Most painters, including myself, don't mind giving one hour of our time, but if you want in depth answers, consider finding a contractor for a professional examination. Rates vary, but I charge about $60 for a written and oral examination, with consideration to the traveling time involved. A paid evaluation 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 require specific answers.
Sound Quality Painting
824 90th Dr SE suite B
Lake Stevens WA 98258
(425) 512-7400
