MORE ABOUT STAINS AND PAINTS
Nearly every kind of surface, from drywall to concrete, needs protection from the elements. These dangerous elements can range between raging blizzards to innocent looking sunlight on a bed room wall. The total thickness of the paint that ends up outside of your residence is usually about one tenth the thickness of your own skin, and interior paint is even thinner. We ask a great deal of that coating of skin. What it can do is determined by a number of factors, like the quality and brand of paint or stain, and exactly how well the walls are prepared and painted.
Paint and stain should be durable, resisting fading and abrasion and allowing repeated washings. Interior paint should go on with minimal spattering. An excellent interior stain or clear finish should resist fading, peeling, or yellowing, and also be easy to maintain, free of impurities or waxes which could collect dirty residue and make cleaning or recoating difficult. Exterior paints should dry with a toughness that resists deterioration from all types of exposure, and an elasticity which provides for constantly expanding and contracting surfaces. With their thorough penetration and level of resistance to ultraviolet (UV) light, the stains and finishes on your home's outdoor surfaces should give a similar high performance.
The Evolution of Stain and Paint
The oldest known paint was used by the painters of Lascaux, who ground natural pigments with water and a binder that may have been honey, starch, or gum. You may be wondering why these cave paintings have lasted a large number of years while the paint on the south area of your home is peeling after only three winters. Here's why: The continuous mild temperature, humidity, and dark interiors of caves are ideal chemical preservatives. Your home, on the other hand, is subjected to a myriad of weather and conditions.
The Egyptians knew as early as 1000 B.C. that paint could protect as well as decorate. Beeswax, vegetable oils, and gum arabic were warmed and blended with Earth and plant dyes to paint images that have lasted a large number of years. The Egyptians used asphalt and pitch to protect their paintings. The Romans later used white lead pigment, developing a formula that would exist almost unchanged until 1950.
The Chinese used oil from the Tung tree to cement the Great Wall, and also to preserve wood. The Chinese used gums and resins to make advanced varnishes such as, shellac, turpentine, copal, and mastic. The formulas and applications for those varnishes also improved little during the centuries.
Milk paint dates back to Egyptian times, was widely used until the late 1800’s when oil-based paints were introduced. Odorless and non-toxic, milk paint today is being revived as an alternative interior paint. Cassein, the protein in milk, dries very even and hard, and can be tinted with other pigments. Like stains, milk paint needs to be covered with a wax or varnish, and is also very durable.
Fashioned from hogs' bristles, badger and goat hair, brushes also transformed little for many centuries. Bristles were hand bound, rosined, and greased, then hand laced in to the stock of the brush. Hog's hair brushes, called China bristle brushes, remain a preferred brush for oil-based paints.
Pigments originally came from anything that bore a color, from ground up Egyptian mummies to street dirt and grime. Most mineral or inorganic pigments originated from rust, potassium, sea salt, sulphur, alum (aluminum), and gypsum, amongst others. Some extravagant works incorporated valuable stones such as lapis lazuli. Hundreds of organic pigments from plants, insects, and animals composed all of those other painter's palette.
Paints and stains changed little from the time of the Pharaohs to the Industrial Revolution. A book on varnishes published in 1773 was reprinted 14 times until 1900, with only slight revisions. However, the colder climates of northern Europe did bring about the necessity for more lasting paint, and in the 1500s the Dutch designer Jan van Eyck developed oil-based paint.
Starting around the Middle Ages lead, arsenic, mercury, and various acids were used as binders and color enhancers. These and other metals made the mixing and painting process hazardous. Paints and varnishes were usually blended on site, in which a ground pigment was blended with lead, oil, and solvents over sustained high temperature. The maladies that arose from dangerous exposure were common among painters at least before late 1800s, when paint companies started out to batch ready mixed coatings. While exposure to toxins given off during the mixing process subsided, contact with the harmful elements inherent in paints and stains didn't change much before 1960s, when companies ceased making lead based paints.
World War I forced the U.S. painting industry to modernize. Manufacturers had to find a replacement for the natural pigments and dyes that originated from Germany. They started to synthesize dyes. Today many pigments and dyes are chemically synthesized.
Innovations in the painting industry have extended well beyond pigments. Water-based latexes have gained in popularity as a safe, quality option to oil-based paints. Latexes have evolved from simple "whitewashes" to highly advanced coatings that can outlast oil-based products. Both oil-based and latex coatings are emerging annually with distinctive improvements, such as the ground metal or glass that's now added to reflect destroying UV light.
A milestone in the evolution of coatings occurred in the very early 1990s with the introduction of a new class of paints and stains known as "water borne." Created by the necessity to adhere to stricter regulations, water borne coatings decrease the volatile organic materials, or VOCs, within standard paint and stains. Harmful and flammable, VOCs evaporate as a coating's solvent dries. They can be inhaled or soaked up through the skin, and create ozone pollution when subjected to sunlight.
PAINTS AND STAINS CHEMISTRY Paints and stains contain four basic types of substances: solvents, binders, pigments, and additives.
Binders and Solvents
Solvents are the vehicle or medium, for the substances in a paint or stain. They regulate how fast a coating dries and exactly how it hardens. Water and alcohol are the main solvents in latex. Oil-based solvents range between mineral spirits (thinner) to alcohols and xylene, to napthas. The solvent also contains binders, which form the "skin" when the paint dries. Binders give paint adhesion and longevity. The cost of paint is based in large part upon the grade of its binder.
Because water is the vehicle in latex paint, it dries quickly, allowing for recoating the same day. The odor that you notice when using a latex paint or stain is the "flashing," or evaporation, of the binder and solvents. The binders in latex are minute, suspended beads of acrylic or vinyl acrylic that "weld" as the paint dries. Latex enamels contain a increased amount of acrylic resins for increased hardness and durability.
Alkyds and oil-based paints are simply the same thing. The word alkyd is derived from "alcid," a combination of alcohol and acid that acts as the drying agent. Both have the same binders, which might include linseed, soy, or Tung oils. Oil based and alkyd enamels may contain polyurethanes and epoxies for extra hardness. Alkyd paints come in high performance combinations such as two part polyester-epoxy for professional use and a urethane altered alkyd for home use. Urethane boosts longevity.
Water borne coatings use a two part drying system: water is the drying agent, and oils form a hard-drying resin. These new coatings match and sometimes out perform their oil-based cousins. They resist yellowing, are more durable, require only water clean-up, have little odor, and are non-flammable. One disadvantage: They swell solid wood grain and require sanding between coats.
Stain and Paint Pigments
Pigments are the costliest element in paint. Besides providing color, pigments also affect paint's hiding power - its potential to hide an identical color with as few coats as you can. Titanium dioxide is the primary and most expensive ingredient in pigment. Top quality paints not only have significantly more titanium dioxide, but also more finely ground pigment. Inexpensive paints use coarsely ground pigment, which doesn't bind well and washes off easier.
Paint and Stain Additives
Additives regulate how well a paint contacts, or wets, the surface area. In addition they help paint flow, level, dry, and resist mildew. Oil is the surfactant, or wetting agent, in oil-based paint. These paints have a natural thickness and potential to flow and level; they go on smoother than latex and dry more slowly, so brush marks have more time to level out. That's why oil-based paints have a tendency to run on vertical areas more than latexes do.
Latex paint has been trying to catch up with oil-based paint over time. Today many latexes outperform oil-based paints and primers, thanks to thickeners, wetting agents (soapy substances that are also known as surfactants), drying inhibitors, defoamers, fungicides, and coalescents. Defoamers keep latex paint from bubbling and leaving pinpricks (called "pin holing") in the paint as it dries. Bubbling is induced when the soap wetting agent rises to the surface as it dries. The better the paint, the less pin holing you should have. It used to be that if latex paint was shaken at the paint store you had to let it to settle for a couple of hours. It is no longer the case with better paints, which is often opened up and used right from the shaker with no threat of pin holing.
Coalescents help latex resins bond, especially in colder weather. Oil-based paint, because it dries slowly and resists freezing, can stick and dry in temperatures from 50°F to 120°F. With added coalescents and, contrary to popular belief, antifreeze, some latexes can be applied in the same temperatures range, and even lower. Some outside latexes can be properly applied at conditions at only 35°F. Companies including Pratt & Lambert, Pittsburgh Paint, and Sherwin Williams have removed the surfactants to help their latex paints be applied in lower conditions. As the wetting agents have been removed, the latex dries faster.
UV blocking chemicals have been added to paints and stains to help slow the aging process. Sunlight is accountable for a lot of the break down of any covering. It fades colors, dries paint, and increases the expansion and contraction process that makes paint crack and peel. UV blockers in paint may contain finely ground metals and ground glass which is currently being added for even greater reflection of the sun's rays.
If you stay in a region with a lot of humidity, rain, and insects, you may need to consider adding a biocide or fungicide to your paint. Biocide deters insects, and fungicide counters mildew. Many coatings already contain some fungicide, but only in small concentrations because of strict interstate regulations.
Sound Quality Painting
824 90th Dr SE suite B
Lake Stevens WA 98258
(425) 512-7400
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