WHAT PAINTS AND STAINS DO
Almost every kind of surface, from drywall to concrete, needs protection from the elements. These dangerous elements can range from raging blizzards to innocent looking sunlight on a dining 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 whole lot of that coating of skin. What it can do is determined by a variety of factors, like the quality and brand of paint or stain, and exactly how well the areas are prepared and painted.
Paint and stain should be durable, resisting fading and abrasion and allowing repeated washings. Interior paint should go on with reduced spattering. An excellent interior stain or clear coating should resist fading, peeling, or yellowing, and also be easy to keep, free from impurities or waxes which could collect dirty residue and make cleaning or recoating difficult. External paints should dry with a toughness that resists deterioration from all types of exposure, and an elasticity which provides for constantly expanding and contracting areas. With their thorough penetration and amount of resistance to ultraviolet (UV) light, the stains and finishes on your home's external surfaces should provide a similar high performance.
A Brief 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 might 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 area of your house is peeling after only three winters. Here's why: The regular mild temperature, humidity, and dark interiors of caves are ideal preservatives. Your home, on the other hand, is subjected to all sorts 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 warmed and blended with Earth and flower dyes to paint images which have lasted a large number of years. The Egyptians used asphalt and pitch to preserve 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 changed little during the 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 is being revived as an excellent interior paint. Cassein, the protein in milk, dries very flat and hard, and can be tinted with other pigments. Like stains, milk paint needs to be sealed with a wax or varnish, which is very durable.
Created from hogs' bristles, badger and goat hair, brushes also improved little for many 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, remain a preferred brush for oil-based paints.
Pigments originally originated from anything that bore a color, from ground up Egyptian mummies to road dirt. 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 and natural 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 shared in 1773 was reprinted 14 times until 1900, with only modest revisions. However, the colder climates of northern Europe did bring about the need for more lasting paint, and in the 1500s the Dutch artist Jan van Eyck developed oil-based paint.
Starting around 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 unsafe. Paints and varnishes were usually combined on site, where a ground pigment was mixed with lead, oil, and solvents over sustained high heating. The maladies that arose from toxic exposure were common amongst painters at least until the late 1800s, when paint companies began to batch ready mix coatings. While contact with contaminants given off during the mixing process subsided, contact with the harmful elements 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 discover a replacement for the natural pigments and dyes that came 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 improved from simple "whitewashes" to highly advanced coatings that can outlast oil-based products. Both oil-based and latex coatings are emerging each year with notable improvements, including 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 fresh category of paints and stains known as "water borne." Created by the necessity to comply with stricter regulations, water borne coatings reduce the volatile organic compounds, 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 the skin, and create ozone pollution when subjected to sunlight.
STAINS AND PAINTS... THEIR 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 finish dries and how it hardens. Water and alcohol are the primary solvents in latex. Oil-based solvents range between 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 toughness. The cost of paint will depend 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 see 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 greater amount of acrylic resins for increased hardness and durability.
Alkyds and oil-based paints are simply the same thing. The word alkyd comes from "alcid," a combo 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 industrial use and a urethane modified 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 raise solid wood grain and require sanding between coats.
Stain and Paint Pigments
Pigments will be the costliest component in paint. Besides providing color, pigments also have an impact on paint's hiding power - its capability to hide an identical color with as few coats as you possibly can. Titanium dioxide is the primary the most expensive ingredient in pigment. Top quality paints not only have more titanium dioxide, but also more finely ground pigment. Inexpensive paints use coarsely ground pigment, which doesn't bind well and washes off more easily.
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 ability to flow and level; they go on smoother than latex and dry more slowly, so brush stridations have more time to level out. That's why oil-based paints tend to run on vertical surfaces more than latexes do.
Latex paint has been playing 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 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 brought on when the soap wetting agent rises to the surface as it dries. The better the paint, the less pin holing you will have. It used to be that if latex paint was shaken at the paint store you had to allow it to settle for a couple of hours. This is no longer the case with better paints, which can be 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 temps from 50°F to 120°F. With added coalescents and, contrary to popular belief, antifreeze, some latexes can be employed in the same heat range, and even lower. Some outdoor latexes can be properly applied at temperature 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 conditions. As the wetting agents have been removed, the latex dries faster.
UV blocking additives have been put into paints and stains to help slow the aging process. Sunlight is accountable for much of the break down of any covering. It fades colors, dries paint, and adds to the expansion and contraction process which makes paint crack and peel. UV blockers in paint may contain finely ground metals and ground glass which is now being added for even more reflection of the sun's rays.
If you reside in an area with lots 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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