WHAT STAINS AND PAINTS DO - PART 2
This is part 2 of a 2 part series of articles on paints and stains.
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 could last longer. It may 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 inside surface. Exterior paints contain special additives designed to withstand the outdoors. 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. In fact, latex has overtaken oil-based paint in a number of areas: durability and elasticity, as well as ease of use, clean-up, and disposal. Latexes have fewer VOCs than oil-based paints. Some, including the Pristine line made by Benjamin Moore, are created without VOCs in any way. Today's latexes are made with top quality pigments and binders that provide them more body, so they go on thicker.
Latexes enjoy quite a lttle bit of attractiveness for interior applications, specifically for walls and ceilings. Alkyds remain the professionals' choice for trim 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 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 a large amount of moisture moving through the surfaces and siding. Water is highest in the baths and kitchen. If these rooms aren't sufficiently ventilated, water will migrate through the walls. Vapor barriers help to contain wetness, but vapor always seeks to escape. The structure of a home, the type of vapor barrier they have, ventilation, and humidity all make choosing 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 moisture go through, unlike alkyd paints, which form a waterproof seal. Alkyds also don't flex with areas that expand and contract, as wood does, especially in colder climates. Latex paints have more elasticity, allowing better adhesion.
I prefer using latex on most exterior surfaces, including wood siding, stucco, and concrete. Latexes avoid 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 do a great job of covering cement. Despite its hardness, cement is very porous, and oil-based paints don't always adhere 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 requires water. Thinners add yet another expenditure, are hard to dispose of, and usually finish up spattered on my skin or clothes, no matter how careful I am.
Improve Your Staining for Interior Work
You may spend a life studying stains and sealers, but there's nothing mysterious about them. The bottom line in determining which stain to utilize is to become acquainted 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.
Exterior stains come in oil based, varnish, polyurethane, and water-borne solvents. Stains have less colorant than paint plus more solvents, giving them greater wood penetration. Waterproofing is a priority with exterior stains. Most come with built-in sealants to increase 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 coating. 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 draw 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 are looking for darker results, a dyed stain provides what you would like in one layer (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 require touching up, so make sure to consider the ease of maintenance in your use of stains. You'll receive 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 has had most of the liquid solvent removed. Gels are simple to use. They wipe 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 difficult 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 working with them for hardwoods, which require a good dye stain to emphasize the depth and beauty of the grain.
Sanding Sealers Are an Exciting Paint Product
Sanding sealers are interior primers that both penetrate and seal wood. You can 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 similar to varnish, but diluted with solvents to allow better penetration for priming. The hardness of varnishes and lacquers prevents them from soaking in to the wood pores. Sanding sealer can provide 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 by using a sanding sealer with shellac, make sure it will not affect 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 likewise have high VOCs, although less than their shellac based cousins. Pittsburgh Paints makes a slow drying alkyd resin sanding sealer without shellac called Rez 77-1. This specific primer/sealer is wonderful for both interiors and exteriors. Pratt & Lambert's Latex Sanding Sealer has very low VOCs, but is purely for interior wood and must not be used under a water borne polyurethane.
Oil-based sanding sealers also can be used to seal outdoor wood, especially decking, which is continually subjected to sun and water. For color reliability 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, and most top quality deck stains are excellent water repellent sealers that can also 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 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, entry 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 endure 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 completely clean and maintain with soap and water accompanied by a wiped on varnish, which usually keeps a wood surface looking great for years. Make certain there is no wax in your cleaner, because wax clogs wood pores. I favor using Hope's Tung Oil varnish for a wipe-on maintenance layer. Lacquer is a quick dry sealer that more often than not must be sprayed, since it becomes tacky almost immediately.
Polyurethanes do almost everything shellac can do, 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 that 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 provide a very hard finish 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 based 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 tend to raise the grain. They'll also harden or "flash off" quickly at temperatures greater 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 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.
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 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 will often have more solids when compared to a typical outside stain, which make them more durable. I would recommend buying a high-end stain that is semi-transparent or what's called a trans-oxide. Until recently, the significant problem with exterior stains was their low UV resistance, but newer trans-oxides have finely ground metal mixed in for higher 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 believe extra protection is needed to combat 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 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, silicon deteriorates quickly, usually in just a matter of months, leaving 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 outside siding, nonetheless they are too soft to be utilized on your deck. Removing these coatings can take gallons of wood cleaner and a significant amount of work.
Water borne exterior stains, such as Sherwin Williams Woodscapes, incorporate the benefits of oil-based and latex coatings. They run and drip significantly less than oil based stain, and dry faster, enabling two coatings the same day. Water borne stains have the resilience and overall flexibility of the latex stain, giving them lasting strength. They're a good choice for some applications. But bear in mind that clearing up water based stains will take work. You will find a couple of oil components in the solvent which may 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.
When In Doubt, Ask Questions
If you still have questions about which paint or stain to work with, please ask people in the know. An experienced, experienced salesperson can clear up any questions it's likely you have. Choose a paint store with staff having at least 10 years 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 their own products, after all, that's why they're running a business. Painting contractors may not be impartial, either. They need to sell their know-how. I get tons of calls from people wanting assistance with their painting problems. Most painters, including myself, don't mind giving an hour of time, but if you need comprehensive answers, consider finding a contractor for a professional examination. Rates vary, but I usually charge about $60 for a written and oral evaluation, depending on the traveling time involved. A paid examination will let you know 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 require specific answers.
Sound Quality Painting
824 90th Dr SE suite B
Lake Stevens WA 98258
(425) 512-7400
