FEATURES OF STAINS AND PAINTS - PART TWO
This is part two of a 2 part series of articles on paints and stains.
Problem Solved - Finally, 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 could last longer, but as I then 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 designed to withstand the outside. 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. Actually, latex has overtaken oil-based paint in several 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 series made by Benjamin Moore, are created without VOCs whatsoever. Today's latexes are created with higher quality pigments and binders that give them more body, so they go on thicker.
Latexes enjoy quite a bit of popularity for interior applications, specifically for walls and ceilings. Alkyds continue to be the professionals' choice for trimming work because oil based paints are simpler to paint on detailed surfaces like molding and trim. However, that traditional school of thought is slowly changing as better latexes, including Pratt & Lambert's Accolade Interior Acrylic Semi Gloss, come on the market.
Exactly What You Are Looking For - Exterior Paint Coatings
Moisture is an important concern for exterior paint selection. Each day a family group of four will generate several gallons of vaporized water in the house.
Combined with naturally occurring humidity, this can mean a a large amount of moisture moving through the wall surfaces 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 to contain wetness, but vapor always seeks to leave. The structure of a house, the type of vapor barrier they have, ventilation, and moisture 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 moisture pass through, unlike alkyd paints, which form a waterproof seal. Alkyds also don't flex with surfaces that expand and contract, as wood does, especially in colder climates. Latex paints have significantly more elasticity, allowing better adhesion.
I prefer using latex on most exterior areas, including wood siding, stucco, and cement. Latexes resist fading much 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 concrete. 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 will provide superior performance, I will choose it over an oil-based product that must be cleaned with a thinner.
Latex only needs water. Thinners add yet another expense, are hard to get rid of, and usually finish up spattered on my skin or clothes, regardless of how careful I am.
How to Stain Interior Surfaces
You could spend a life studying stains and sealers, but there's nothing mysterious about them. The bottom line in determining which stain to work with is to become acquainted with the product lines 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 more solvents, giving them better wood penetration. Waterproofing is important with exterior stains. Most include built-in sealants to add sturdiness 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 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 always 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, which are much easier to apply, combine, 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 will provide what you want in one coating (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 need touching up, so make certain to consider the ease of maintenance in your choice 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 the majority of the water solvent removed. Gels are easy to use. They wipe on, dry out 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 troublesome to cover 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 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 on top of stains as sealers. Sanding sealers are different from a sealer like polyurethane, which is not made to prime. They're more like varnish, but diluted with solvents to permit 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 adherence 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're using a sanding sealer with shellac, make sure it won't affect the stain. Shellacs have a tendency to yellow aver time and contain toluene, which has a very 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 dry 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 strictly for interior wood and must not be used under a water based polyurethane.
Oil-based sanding sealers also can be utilized to seal exterior wood, especially decking, which is continually exposed to sun and water. For color uniformity 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 excellent water repellent sealers that also can be used for priming outside wood.
No-Fuss 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 on top of a stain, or used as a clear coating on unstained wood trim. They could be used for just about any type of trim, including windows, entry doors, and the casing around them. Although you can buy stain/sealer combinations, they have a tendency to yellow, are difficult to keep up, and don't last as long as separately applied stain and sealers.
Varnishes contain 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 keep maintaining with soap and water accompanied by a wiped on varnish, which usually keeps a wood surface looking great for years. Make certain there's 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 coat. Lacquer is a fast drying sealer that almost always needs to be sprayed, since it becomes tacky almost immediately.
Polyurethanes do almost anything shellac does, but they're easier to maintain. While shellacs act like paint, polyurethanes act more like a clear coating that permeates the wood instead of resting on top of 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 become such popular sealers is the fact that they don't really require sanding sealers.
The odors associated numerous paints and stains can become more than simply offensive, they can be toxic. Solvent based varnishes, lacquers, and shellacs provide a very hard coating 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 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 set up or "flash off" quickly at temps 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 cases like this, 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 put it on 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.
Method for Stains and Sealers on Exteriors
Due to their better penetration and sealing ability, most exterior stains sold today are oil-based. However, oil-based solid stains peel off 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 which is simpler 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 will often have more solids than a typical outside stain, which will make them stronger. I recommend buying a high-end stain that is semi-transparent or what's called a trans-oxide. Until lately, the major problem with outdoor stains was their low UV resistance, but newer trans-oxides have finely ground metal mixed in for greater protection. A high end deck stain won't need a different sealer overcoat, although you can add one (such as Olympic Water Guard) if you believe extra protection is required to fight dampness and sun exposure. Better deck stains retail for about $35 a gallon and cover 300 to 400 sq. ft.
Avoid using deck stains which contain silicone. Despite their attractive price, they are not 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 the indication of a successful coating. However, silicon deteriorates quickly, usually in just a matter of months, producing a discolored, waxy coat that is 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, nonetheless 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 borne 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, allowing for two coatings the same day. Water based stains have the resilience and overall flexibility of the latex stain, giving them stamina. They're a great choice for some applications. But bear in mind that cleaning up water borne stains requires 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 seller for specific cleaning guidelines for water borne stains, and read the label.
Ask Your Painting Professional When In Doubt
If you still have questions about which paint or stain to work with, please ask people in the know. An experienced, educated salesperson can clear up any questions you might 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 merchandise in question.
The answers you get will rely upon whom you ask. A paint store will try to market you one their own products, after all, that's why they're running a business. Painting contractors might not be impartial, either. They need to sell their know-how. I get tons of calls from people needing assistance with their painting problems. Most painters, including myself, don't mind giving an hour of our time, but if you want comprehensive answers, consider finding a contractor for a professional evaluation. Rates vary, but I charge about $60 for a written and oral analysis, 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 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
