WHAT PAINTS AND STAINS DO - PART TWO
This is part 2 of a 2 part series of articles on paints and stains.
Exactly What You Are Looking For - 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 would last longer. It may last longer, but as I found out when I needed to touch up the ceiling only 2 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 out to a durable, uniform finish.
Most of the advances in painting technology have been with latex. Actually, latex has overtaken oil-based paint in a number of areas: strength and elasticity, as well as ease of use, clean-up, and disposal. Latexes have fewer VOCs than oil-based paints. Some, like the Pristine brand made by Benjamin Moore, are created with no VOCs at all. Today's latexes are made with top quality pigments and binders that give them more body, so each goes on thicker.
Latexes enjoy quite a lttle bit of popularity for interior applications, specifically for walls and ceilings. Alkyds stay the professionals' choice for trim work because oil based paints are better to paint on detailed surfaces like molding and hardwood 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.
Exactly What You Are Looking For - Exterior Paint Coatings
Moisture is an important consideration for exterior paint selection. Every day a family of four will create several gallons of vaporized water inside a house.
Combined with naturally occurring humidity, this may mean a lot of moisture moving through the wall space and siding. Moisture is highest in the baths and kitchen. If these rooms aren't sufficiently ventilated, moisture will migrate through the walls. 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 moisture all make choosing 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 water go through, unlike alkyd paints, which form a waterproof seal. Alkyds also don't flex with surfaces that expand and shrink, as wood does, especially in colder climates. Latex paints have more elasticity, allowing better adhesion.
I favor using latex on all exterior surfaces, including wood siding, stucco, and masonry. Latexes withstand 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, cement is very porous, and oil-based paints don't always adhere well. For very best durability, I recommend latex enamel.
In general, if I know of a latex product that will provide 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 expenditure, are hard to get rid of, and usually end up spattered on my skin or clothes, regardless of how careful I am.
Solution For Staining Inside
You are able to spend a life time learning about stains and sealers, but there's nothing mysterious about them. The bottom line in determining which stain to utilize is to familiarize yourself with the products available. Read the label, along with any product information you can get, and talk 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 even more solvents, providing them with greater wood penetration. Waterproofing is important with exterior stains. Most include built-in sealants to add toughness 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 is why a pigmented stain is definitely 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, mix, and touch up. Pigmented stains are lighter in color and bring out more of the wood grain. If you're looking for darker results, a dyed stain will provide 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 extremely difficult to touch up. Every coating eventually will require touching up, so be sure 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 stay away from the watery nature of stains, get a gel stain, which had the majority of the liquid solvent removed. Gels are simple 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 troublesome to coat evenly without 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.
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 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 permit 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 tend to be added to sanding sealers to fortify the resin and offer an instant drying agent. They also add an amber tone, so if you are using a sanding sealer with shellac, make sure it will not have an effect on the stain. Shellacs tend to yellow aver time and contain toluene, which 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 also have high VOCs, although 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 only for interior wood and must not be used under a water based polyurethane.
Oil-based sanding sealers also can be used to seal exterior wood, especially decking, which is continually exposed to sun and water. For color consistency in areas like decks, it's best 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, & most top quality deck stains are excellent water repellent sealers that also can be used for priming outdoor wood.
Wood and Stain Sealers Solution for 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 coating on unstained wood trim. They can be used for any type of trim, including windows, doors, and the casing around them. Although you can purchase stain/sealer combinations, they tend 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 maintain with soap and water accompanied by a wiped on varnish, which often keeps a wood surface looking great for years. Make certain there is no wax in your cleaner, because wax clogs wood pores. I prefer making use of Hope's Tung Oil varnish for a wipe-on maintenance coating. Lacquer is a quick drying sealer that almost always must be sprayed, since it becomes tacky almost immediately.
Polyurethanes do almost everything shellac does, but they're better to maintain. While shellacs act like paint, polyurethanes act more like a clear coating that permeates the wood instead of sitting on it. Polyurethanes brush on and dry 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 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 covering but contain high VOC levels. Water borne 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 usual 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 tend to raise the grain. They'll also harden or "flash off" quickly at conditions higher than 60°F. The very best working temperature for most water based 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 complete the drying out 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, and others.
Method for Stains and Sealers on Exteriors
Because of 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 difficult to maintain. A solid stain is similar to paint: It coats more than it penetrates. A latex solid stain peels less and it is better 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 when compared to a typical exterior 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 recently, 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 different sealer coating, although you can add one (such as Olympic Water Guard) if you think extra protection is required to combat moisture and sun exposure. Better deck stains retail for approximately $35 a gallon and cover 300 to 400 sq. ft.
Avoid using deck stains that contain silicone. Despite their low price, they aren't 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 actually the indication of an effective coating. However, silicone deteriorates quickly, usually in just a matter of months, producing a discolored, waxy coat that is clearly a pain to remove. The deteriorated silicone also stops repelling water.
"High build" coatings such as Sikkens and Messmers work remarkably well on outside siding, nevertheless they are too soft to be utilized on your deck. Stripping these coatings can take gallons of wood cleaner and a significant amount of work.
Water borne outside stains, such as Sherwin Williams Woodscapes, combine the advantages of oil-based and latex coatings. They run and drip significantly less than oil based stain, and dry out faster, allowing for two coatings the same day. Water borne stains possess the resilience and versatility of your latex stain, which gives them lasting strength. They're a good choice for some applications. However that cleaning up water based stains calls for work. There are a couple of oil components in the solvent which have to be cleaned. First use soap and water, then alcohol. Ask your seller for specific cleaning directions 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, don't hesitate to ask people in the know. An experienced, proficient salesperson can clear up any questions you might have. Look for a paint store with staff having at least 10 years of experience in the business. Inquire further what has worked best for your unique application and ask to read 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 market you one of their products, after all, that is why they're running a business. Painting contractors may not be impartial, either. They need to sell their expertise. I get lots of calls from people looking for assistance with their painting problems. Most painters, including myself, don't object to giving an hour of time, but if you want comprehensive answers, consider finding a contractor for a professional examination. Rates vary, but I charge about $60 for a written and oral examination, depending on the traveling time included. A paid evaluation will tell you whether you should paint, stain, or re-side, as well as which coating might be best for finishing 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
