WHAT PAINTS AND STAINS DO - PART II
This is part 2 of a 2 part series of articles on paints and stains.
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 indoor ceiling, reasoning that it could last longer. It could last 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 interior 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. In fact, latex has overtaken oil-based paint in a number of areas: strength and elasticity, as well as ease of application, clean-up, and disposal. Latexes have fewer VOCs than oil-based paints. Some, including the Pristine line made by Benjamin Moore, are made with no VOCs in any way. Today's latexes are created with higher quality pigments and binders that provide them more body, so they go on thicker.
Latexes enjoy quite a lttle bit of acceptance for interior applications, especially for walls and ceilings. Alkyds stay the professionals' choice for trim work because oil based paints are simpler 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, are introduced to the market.
Exterior Paints Coatings for Each Job
Moisture can be an important concern for exterior paint selection. Each 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 lot of moisture moving through the wall 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 to contain wetness, but vapor always seeks to leave. The structure of a house, the kind of vapor barrier they have, ventilation, and moisture all make selecting the right paint critical.
In wetter climates you require 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 dampness pass through, unlike alkyd paints, which form a waterproof seal. Alkyds also don't flex with floors that expand and contract, as wood will, especially in colder climates. Latex paints have significantly more elasticity, allowing better adhesion.
I prefer using latex on all exterior surface areas, including wood siding, stucco, and concrete. Latexes withstand fading better than most oil-based paints, and they will cover either oil-based or latex primer (most oils have to go on top of 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 stick well. For ideal durability, I would recommend latex enamel.
In general, if I know of a latex product that provides superior performance, I'll choose it over an oil-based product that must 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.
Here’s What You Should Do When Staining Inside
You can spend a life time studying stains and sealers, but there is nothing mysterious about them. The bottom line in determining which stain to utilize is to become acquainted with the product lines available. Read the label, along with any product information you can get, and talk to the personnel 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, giving them greater wood penetration. Waterproofing is a priority with exterior stains. Most include built-in sealants to add sturdiness 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 coating. Pigment is a finely ground coloring that doesn't penetrate the grain as deeply as a dye. That's why a pigmented stain is often used along with a sealer such as urethane or varnish.
Some high quality interior stains have dyes to penetrate and pigments to draw out the richness of the grain. Others contain only pigments, that are easier to apply, blend, 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 provides what you would like in one coat (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 make certain to consider the 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 wish to avoid the watery nature of stains, get a gel stain, which had most of the liquid solvent removed. Gels are easy to use. They wipe on, dry fast, and cover evenly. Since they're colored with pigment, gel stains don't penetrate that well. They're a great choice for porous woods that are hard to cover evenly without a toner. Gel stains do a great job of showing off the grain on embossed metal or composite surfaces. I don't recommend working with 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 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 can offer a better adherence for clear coats.
Shellacs tend to be added to 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 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 slowly giving ways to new sanding sealer formulas with lower VOCs and better performance.
Alkyd resin sanding sealers also have high VOCs, although significantly less than their shellac based cousins. Pittsburgh Paints makes a slow drying alkyd resin sanding sealer without shellac named Rez 77-1. This particular primer/sealer is wonderful for both interiors and exteriors. Pratt & Lambert's Latex Sanding Sealer has suprisingly low VOCs, but is strictly for interior wood and must not be used under a water borne polyurethane.
Oil-based sanding sealers can also be utilized to seal outside wood, especially decking, which is constantly 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 is in place, 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 used for priming outdoor wood.
Method for Wood and Stain Sealers on Interior Wood
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 coat on unstained wood trim. They can be used for just about any type of wood trim, including windows, entrance 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 endure as long as separately applied stain and sealers.
Varnishes contain natural oils such as Tung oil, a very hard, durable sealant that can 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 ideal for years. Make certain there's no wax in your cleaner, because wax clogs wood pores. I prefer utilizing 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 anything shellac does, but they're simpler to maintain. While shellacs act like paint, polyurethanes act more like a clear coat that permeates the wood instead of sitting 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 become such popular sealers is that they don't really 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 provide a super hard covering 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 based 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 have a tendency to raise the grain. They will also set up or "flash off" quickly at conditions higher than 60°F. The best working temperature for nearly all 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 finish the drying out process. A contractor I know once used water borne 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 borne polyurethane, as do Pittsburgh, Pratt & Lambert, Benjamin Moore, as well as others.
Improved Exterior Stains and Sealers
Due to their better penetration and sealing power, most exterior stains sold today are oil-based. However, oil-based solid stains peel off as they get older, making them more challenging to maintain. A solid stain is similar to paint: It coats more than it penetrates. A latex solid stain peels less and is also much 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 market 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's called a trans-oxide. Until just lately, the significant problem with outside stains was their low UV resistance, but newer trans-oxides have finely ground metal mixed in for increased protection. A higher end deck stain won't need a different sealer overcoat, although you can include one (such as Olympic Water Guard) if you think extra protection is required to battle wetness 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 low price, they are not a good deal. Advertisements for silicon 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 a matter of months, leaving a discolored, waxy coat that is clearly a pain to remove. The deteriorated silicone also ceases repelling water.
"High build" coatings such as Sikkens and Messmers work remarkably well on outside siding, nonetheless they are too soft to be used on your deck. Removing these coatings needs gallons of wood cleaner and a significant amount of work.
Water based 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 based stains possess the resilience and overall flexibility of a latex stain, which gives them lasting strength. They're a good choice for most applications. But bear in mind that clearing up water borne stains will take work. You can find a couple of oil components in the solvent which may have to be cleaned. First use soap and water, then alcohol. Ask your supplier for specific cleaning directions for water borne stains, and read the label.
Ask Questions When In Doubt
If you still have questions about which paint or stain to use, don't hesitate to ask people in the know. A skilled, educated salesperson can answer any questions it's likely you have. Look for 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 merchandise in question.
The answers you get will rely upon whom you ask. A paint store will attempt to sell you one their own products, after all, that is why they're in business. Painting contractors may not be impartial, either. They have to sell their expertise. I get a lot of cell phone calls from people needing aid with their painting problems. Most painters, including myself, don't object to giving one hour of our time, but if you need in depth answers, consider hiring a contractor for a professional analysis. Rates vary, but I usually charge about $60 for a written and oral examination, with respect to the traveling time involved. A paid examination will let you know whether you should paint, stain, or re-side, as well as which finish 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
