FEATURES OF STAINS AND PAINTS
Almost every kind of surface, from drywall to concrete, needs protection from the elements. These hazardous elements can range from raging blizzards to innocent looking sunlight on a bed room wall. The full total thickness of the paint that eventually ends up on the exterior of your property is usually about one tenth the thickness of your skin, and interior paint is even thinner. We ask a lot of that coating of skin. What it can do depends upon a variety of factors, like the quality and kind of paint or stain, and how well the areas prepped and painted.
Paint and stain should be durable, resisting fading and abrasion and allowing repeated washings. Interior paint should go on with little spattering. An excellent interior stain or clear coating should resist fading, peeling, or yellowing, and also be easy to maintain, free of impurities or waxes which could collect dirt and grime and make cleaning or recoating difficult. External paints should dry with a toughness that resists deterioration from all sorts of exposure, and an elasticity which provides for constantly expanding and contracting surfaces. With their deep penetration and amount of resistance to ultraviolet (UV) light, the stains and finishes on your home's outside surfaces should provide a similar high performance.
The History of Stain and Paint
The oldest known paint was utilized by the painters of Lascaux, who ground natural pigments with water and a binder that may have been honey, starch, or gum. You might be wondering why these cave paintings have lasted thousands of years as the paint on the south part of your home is peeling after only three winters. Here's why: The regular mild temperature, humidity, and dark interiors of caves are ideal chemical preservatives. Your home, on the other hand, is exposed to all varieties of weather and conditions.
The Egyptians knew as soon as 1000 B.C. that paint could protect as well as decorate. Beeswax, vegetable oils, and gum arabic were heated and mixed with Earth and vegetable dyes to paint images that have lasted thousands of years. The Egyptians used asphalt and pitch to preserve their paintings. The Romans later used white lead pigment, making a formula that would exist almost unchanged until 1950.
The Chinese used oil from the Tung tree to cement the Great Wall, and to preserve wood. The Chinese used gums and resins to make sophisticated varnishes such as, shellac, turpentine, copal, and mastic. The formulas and applications for those varnishes also evolved little in the following centuries.
Milk paint dates back to Egyptian times, was widely used up until the late 1800’s when oil-based paints were introduced. Odorless and non-toxic, milk paint today has been 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 must be coated with a wax or varnish, and is also very durable.
Created from hogs' bristles, badger and goat hair, brushes also changed little for several centuries. Bristles were hand bound, rosined, and greased, then hand laced into the stock of the brush. Hog's hair brushes, called China bristle brushes, are still a preferred brush for oil-based paints.
Pigments originally came from whatever bore a color, from ground up Egyptian mummies to street mud. Most mineral or inorganic pigments came from rust, potassium, sea salt, sulphur, alum (aluminum), and gypsum, amongst others. Some extravagant projects incorporated valuable stones such as lapis lazuli. A huge selection of organic pigments from plants, insects, and animals composed the rest of the 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 artist Jan van Eyck developed oil-based paint.
Starting in the Middle Ages lead, arsenic, mercury, and different acids were used as binders and color enhancers. These and other metals made the mixing and painting process dangerous. Paints and varnishes were usually blended on site, where a ground pigment was mixed with lead, oil, and solvents over sustained high heat. The maladies that arose from toxic exposure were common among painters at least before late 1800s, when paint companies began to batch ready mixed coatings. While exposure to toxins given off during the mixing process subsided, contact with the harmful substances inherent in paints and stains didn't change much until the 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 out to synthesize dyes. Today many pigments and dyes are chemically synthesized.
Inventions in the painting industry have extended well beyond pigments. Water-based latexes have gained in reputation as a safe, quality alternative to oil-based paints. Latexes have altered from simple "whitewashes" to highly advanced coatings that can outlast oil-based products. Both oil-based and latex coatings are emerging every year with notable improvements, such as the ground metal or glass that's now added to reflect harming UV light.
A milestone in the evolution of coatings occurred in the early 1990s with the introduction of a new class of paints and stains known as "water borne." Created by the need to comply with stricter regulations, water borne coatings decrease the volatile organic chemical substances, or VOCs, found in standard paint and stains. Dangerous and flammable, VOCs evaporate as a coating's solvent dries. They could be inhaled or soaked up through your skin, and create ozone pollution when subjected to sunlight.
STAINS AND PAINTS CHEMISTRY Paints and stains contain four basic types of materials: solvents, binders, pigments, and additives.
Solvents and Binders
Solvents are the vehicle or medium, for the ingredients in a paint or stain. They regulate how fast a covering dries and how it hardens. Water and alcohol are the primary solvents in latex. Oil-based solvents range from mineral spirits (thinner) to alcohols and xylene, to napthas. The solvent also includes binders, which form the "skin" when the paint dries. Binders give paint adhesion and resilience. The expense of paint relies in large part upon the grade of its binder.
Because water is the vehicle in latex paint, it dries quickly, enabling recoating the same day. The odor that you notice when utilizing 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 include a greater amount of acrylic resins for greater hardness and durability.
Alkyds and oil-based paints are basically the same thing. The term alkyd comes from "alcid," a mixture of alcohol and acid that acts as the drying agent. Both have the same binders, which may 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 customized alkyd for home use. Urethane boosts strength.
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 stronger, require only water clean-up, have little odor, and are non-flammable. One disadvantage: They swell real wood grain and require sanding between coats.
Pigments
Pigments are the costliest element in paint. Besides providing color, pigments also impact paint's hiding power - its capacity to cover a similar color with as few coats as possible. Titanium dioxide is the principal the 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.
Additives
Additives determine 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 ability to flow and level; they go on smoother than latex and dry more slowly, so brush marks have a chance to level out. That's why oil-based paints have a tendency to drip on vertical surfaces 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, because of thickeners, wetting agents (soapy substances that are also called 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 triggered when the soap wetting agent rises to the top 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 would have to allow it to settle for a few hours. This is certainly no longer the truth with better paints, that can be opened up and used right out of the shaker without danger 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, believe it or not, antifreeze, some latexes can be employed in the same heat range, and even lower. Some exterior latexes can be safely applied at heat at only 35°F. Companies including Pratt & Lambert, Pittsburgh Paint, and Sherwin Williams have removed the surfactants to help their latex paints go on in lower temperature. Because the wetting agents have been removed, the latex dries faster.
UV blocking chemicals have been added to paints and stains to help slow deterioration. Sunlight is responsible for a lot of the breakdown of any covering. It fades colors, dries paint, and adds to the expansion and contraction process that makes paint crack and peel off. UV blockers in paint may contain finely ground metals and ground glass which is now being added for even greater reflection of the sun's rays.
If you reside in an area with plenty of humidity, rainwater, 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
OUR EVERETT PAINTING LOCATION WEBSITE
OUR LYNNWOOD PAINTING LOCATION WEBSITE
OUR MARYSVILLE PAINTING LOCATION WEBSITE
OUR EDMONDS PAINTING LOCATION WEBSITE
