THE PURPOSE OF STAINS AND PAINTS - PART 2
This is part two of a 2 part series of articles on paints and stains.
Finally, Interior Paints Coatings for Each Job
Did 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 may last longer, but as I found out when I had to touch up the ceiling only two years later, exterior paints will discolor on an interior surface. Exterior paints contain special additives designed to withstand the outside. Interior paints have additives that help the paint dry to a durable, uniform 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 created by Benjamin Moore, are made without VOCs whatsoever. Today's latexes are made with higher quality pigments and binders that give them more body, so they go on thicker.
Latexes enjoy quite a bit of acceptance for interior applications, specifically for walls and ceilings. Alkyds stay 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 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. Each 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. Water 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 escape. The structure of a house, the kind of vapor barrier they have, ventilation, and humidity 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 water pass through, unlike alkyd paints, which form a waterproof seal. Alkyds also don't flex with surfaces 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 all exterior areas, including wood siding, stucco, and concrete. Latexes withstand fading much 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 perform a great job of covering cement. Despite its hardness, concrete is very porous, and oil-based paints don't always stay well. For best durability, I 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 should be cleaned with a thinner.
Latex only requires water. Thinners add one more expenditure, are hard to dispose of, and usually finish up spattered on my skin or clothes, regardless of how careful I am.
Amazing Way to Use Stains for Interior Work
You may 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 work with is to familiarize yourself with the products available. Scan the label, along with any product information you can get, and speak to the personnel at a professional paint shop.
Exterior stains come in oil based, varnish, polyurethane, and water-borne solvents. Stains have less colorant than paint and even more solvents, providing them with increased wood penetration. Waterproofing is important with exterior stains. Most include built-in sealants to add durability and help maintain 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 actually accompanied by 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, 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 would like in one coating (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 require touching up, so make sure to consider ease of maintenance in your use 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 steer clear of the watery nature of stains, try a gel stain, which has had the majority of the water 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 good choice for porous woods that are tough to coat evenly with out 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.
Amazing Way to Use 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 stops them from soaking into the wood pores. Sanding sealer can offer a better bond for clear coats.
Shellacs are often added to sanding sealers to fortify the resin and provide a quick drying agent. They also add an amber tone, so if you are using a sanding sealer with shellac, make sure it will not influence the stain. Shellacs have a tendency to yellow aver time and contain toluene, which has a high VOC content. Shellacs are gradually supplying 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 dry 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 suprisingly low VOCs, but is strictly for interior wood and shouldn't be used under a water based 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 reliability in areas like decks, you need to completely coat, or back prime, the wood 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 utilized for priming outdoor wood.
Wood and Stain Sealers 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 coat on unstained wood trim. They can be used for just about any type of trim, including windows, entrance 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 last 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 keep maintaining with soap and water followed 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 using Hope's Tung Oil varnish for a wipe-on maintenance coating. Lacquer is a quick dry sealer that almost always must be sprayed, since it becomes tacky almost immediately.
Polyurethanes do almost anything shellac can do, but they're easier 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 out quickly, with little odor 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 require sanding sealers.
The smells associated numerous paints and stains can become more than simply offensive, they can be toxic. Solvent based varnishes, lacquers, and shellacs give a ultra hard coating but contain very 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 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 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 have a tendency to raise the grain. They'll also harden or "flash off" quickly at temperature ranges greater than 60°F. The very 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 complete the drying process. A contractor I knew 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 based polyurethane, as do Pittsburgh, Pratt & Lambert, Benjamin Moore, and others.
No-Fuss Stains and Sealers for Exteriors
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 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 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 will often have more solids when compared to a typical outside stain, which make them more durable. I recommend buying a high-end stain that is semi-transparent or what is called a trans-oxide. Until just lately, the major problem with outside 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 need a separate sealer overcoat, although you can add one (such as Olympic Water Guard) if you think extra protection is needed to fight wetness 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 low price, they aren't a good deal. Advertisements for silicone 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 a successful coating. However, silicone breaks down quickly, usually in a matter of months, producing a discolored, waxy coat that is clearly a pain to eliminate. The deteriorated silicone also stops 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 way too much work.
Water based exterior stains, such as Sherwin Williams Woodscapes, incorporate the features 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 versatility of a latex stain, giving them lasting strength. They're a good choice for some applications. But bear in mind that clearing up water borne stains needs work. You will find a couple of oil components in the solvent that 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.
Ask Questions When In Doubt
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, proficient salesperson can clear up any questions you might have. Choose a paint store with personnel 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 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 running a business. Painting contractors might not be impartial, either. They need to sell their experience. I get tons of cell phone calls from people desiring help with their painting problems. Most painters, including myself, don't object to giving an hour of 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 evaluation, with respect to the traveling time involved. A paid examination will tell you whether you should paint, stain, or re-side, as well as which covering 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
