THE PURPOSE OF PAINTS AND STAINS PART 2

THE FUNCTION OF PAINTS AND STAINS - PART II

This is part two of a 2 part series of articles on paints and stains.

High Demand 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 would last longer. It may last longer, but as I found out when I had to touch up the ceiling only 2 years later, exterior paints will discolor on an inside surface. Exterior paints contain special additives made to withstand the outdoors. Interior paints have additives that help the paint dry out 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: 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 brand created by Benjamin Moore, are made without VOCs whatsoever. Today's latexes are created with top quality pigments and binders that provide them more body, so each goes on thicker.

Latexes enjoy quite a lttle bit of reputation for interior applications, especially for walls and ceilings. Alkyds continue to be the professionals' choice for trimming work because oil based paints are easier 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, come on the market.

Exterior Paints Coatings for Each Job

Moisture is an important consideration for exterior paint selection. Every day a family group of four will generate several gallons of vaporized water inside a house.

Coupled with naturally occurring humidity, this may mean a a large amount of moisture moving through the wall space and siding. Wetness is highest in the baths and kitchen. If these rooms aren't sufficiently ventilated, moisture will migrate through the wall space. Vapor barriers help contain wetness, but vapor always seeks to escape. The structure of a home, the kind of vapor barrier they have, 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 moisture pass 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 significantly more elasticity, allowing better adhesion.

I favor using latex on all exterior areas, including wood siding, stucco, and masonry. Latexes avoid fading much 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 perform 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 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 yet another expenditure, are hard to dispose of, and usually end up spattered on my skin or clothes, no matter how careful I am.

Improve Your Staining for Interior Work

You are able to spend a life learning about stains and sealers, but there's nothing mysterious about them. The bottom line in determining which stain to make use of is to familiarize yourself with the product lines 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 greater wood penetration. Waterproofing is important with exterior stains. Most include built-in sealants to add durability and help preserve the wood. The color 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 obviously 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 simpler to apply, blend, 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 would like in one layer (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 certain 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 steer clear of the watery nature of stains, get a gel stain, which had almost all of the water solvent removed. Gels are simple to use. They spread 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 troublesome to cover evenly without a toner. Gel stains do a great job of bringing out the grain on embossed metal or composite surfaces. I don't recommend using them for hardwoods, which require a good dye stain to emphasize the depth and beauty of the grain.

How We Improved Our Painting With 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 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 a quick drying agent. In addition they add an amber tone, so if you are 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, that has a very high VOC content. Shellacs are slowly offering 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 named 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 must not be used under a water based polyurethane.

Oil-based sanding sealers can also be utilized to seal exterior wood, especially decking, which is constantly subjected to sun and water. For color regularity in areas like decks, it's best 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, and most top quality deck stains are great water repellent sealers that also can be utilized for priming outdoor wood.

Method for Wood and Stain Sealers on 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 coat on unstained wood trim. They could be used for just about any type of wood 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 can be brushed on and dries slowly. Varnishes are easy to clean and maintain with soap and water accompanied by a wiped on varnish, which usually keeps a wood surface looking ideal for years. Make sure there's no wax in your cleaner, because wax clogs wood pores. I prefer using Hope's Tung Oil varnish for a wipe-on maintenance layer. Lacquer is a fast drying sealer that more often than not must be sprayed, since it becomes tacky almost immediately.

Polyurethanes do almost anything 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 top of it. Polyurethanes brush on and dry out 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 that they don't 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 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 borne sealers such as Sherwin Williams Kern Aqua Lacquer average about 250 grams per liter, or 2 pounds per gallon, half the most common 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 tend to raise the grain. They will also harden or "flash off" quickly at temperatures greater than 60°F. The very best working temperature for most water borne acrylic latex polyurethanes is between 50°F and 60°F, which lets them flash a little 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 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.

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. 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 usually have more solids when compared to a typical outside 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 lately, the major problem with outside stains was their low UV resistance, but newer trans-oxides have finely ground metal mixed in for increased protection. A high end deck stain won't need a different sealer coating, although you can add one (such as Olympic Water Guard) if you think extra protection is needed to combat water and sun exposure. Better deck stains retail for about $35 a gallon and cover 300 to 400 sq. ft.

Avoid using deck stains that contain silicone. Despite their attractive price, they are not 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 a successful coating. However, silicone breaks down quickly, usually in a matter of months, leaving a discolored, waxy coat that is a pain to eliminate. The deteriorated silicone also quits repelling water.

"High build" coatings such as Sikkens and Messmers work remarkably well on outside siding, but they are too soft to be used on your deck. Stripping these coatings takes gallons of wood cleaner and way too much work.

Water based outside stains, such as Sherwin Williams Woodscapes, combine the benefits 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 flexibility of any latex stain, giving them lasting strength. They're a good choice for some applications. However that clearing up water borne stains calls for work. You will find a couple of oil components in the solvent which have to be cleaned. First use soap and water, then alcohol. Ask your supplier for specific cleaning guidelines for water borne stains, and read the label.

When In Doubt, Ask Questions

In the event that you still have questions about which paint or stain to use, don't hesitate to ask people in the know. A skilled, competent salesperson can answer any questions it's likely you have. Look for a paint store with staff having at least 10 years of experience in the business. Ask them 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 depend on whom you ask. A paint store will attempt to market you one their own products, in the end, that is why they're running a business. Painting contractors might not be impartial, either. They need to sell their experience. I get a lot of telephone calls from people needing assistance with their painting problems. Most painters, including myself, don't object to giving one hour of our time, but if you need comprehensive answers, consider finding a contractor for a professional evaluation. Rates vary, but I charge about $60 for a written and oral analysis, depending on 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 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

Sound Quality Painting