MORE ABOUT STAINS AND PAINTS
Nearly every kind of surface, from drywall to concrete, needs protection from the elements. These harmful elements can range from raging blizzards to innocent looking sunlight on a dining room wall. The total thickness of the paint that eventually ends up on the exterior of your residence is usually about one tenth the thickness of your skin, and interior paint is even thinner. We ask a whole lot of that covering of skin. What it can do depends upon a number of factors, including the quality and brand of paint or stain, and exactly how well the surfaces prepped and painted.
Paint and stain should be durable, resisting fading and abrasion and allowing repeated washings. Interior paint can go on with reduced spattering. A quality interior stain or clear coating should resist fading, peeling, or yellowing, and also be easy to keep, free from impurities or waxes that could collect dirty residue and make cleaning or recoating difficult. Outside paints should dry with a toughness that resists deterioration from all sorts of exposure, and an elasticity that allows for constantly expanding and contracting areas. With their thorough penetration and resistance to ultraviolet (UV) light, the stains and finishes on your home's external surfaces should give a similar high performance.
The History of Paint and Stain
The oldest known paint was employed by the painters of Lascaux, who ground natural pigments with water and a binder that might have been honey, starch, or gum. You may 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 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 heated and mixed with Earth and herb dyes to paint images which have lasted thousands of years. The Egyptians used asphalt and pitch to protect 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 superior varnishes such as, shellac, turpentine, copal, and mastic. The formulas and applications for those varnishes also changed little in the following centuries.
Milk paint goes 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 has been revived as an excellent 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 very durable.
Fashioned from hogs' bristles, badger and goat hair, brushes also evolved 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 came from whatever bore a color, from ground up Egyptian mummies to road 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 treasured stones such as lapis lazuli. Hundreds 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 shared in 1773 was reprinted 14 times until 1900, with only small revisions. However, the colder climates of northern Europe did bring about the need for more durable paint, and in the 1500s the Dutch artist Jan van Eyck developed oil-based paint.
Starting during 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 mixed on site, in which a ground pigment was mixed with lead, oil, and solvents over sustained high heating. The maladies that arose from harmful exposure were common among painters at least before late 1800s, when paint companies started to batch ready mixed coatings. While exposure to contaminants given off during the mixing process subsided, contact with the harmful ingredients 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 alternative to the natural pigments and dyes that came from Germany. They started 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 level of popularity 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 annually with well known 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 early 1990s with the introduction of a new category of paints and stains known as "water borne." Created by the need to comply with stricter regulations, water borne coatings decrease the volatile organic ingredients, or VOCs, within standard paint and stains. Poisonous and flammable, VOCs evaporate as a coating's solvent dries. They can be inhaled or absorbed through your skin, and create ozone pollution when subjected to sunlight.
PAINTS AND STAINS CHEMISTRY Paints and stains contain four basic types of ingredients: solvents, binders, pigments, and additives.
Paint and Stain Solvents and Binders
Solvents will be the vehicle or medium, for the ingredients in a paint or stain. They regulate how fast a coating dries and 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 sturdiness. 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, allowing for 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 contain a better amount of acrylic resins for better hardness and durability.
Alkyds and oil-based paints are basically the same thing. The word alkyd is derived from "alcid," a blend 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 powerful combinations such as two part polyester-epoxy for industrial use and a urethane altered alkyd for home use. Urethane boosts toughness.
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 real wood grain and require sanding between coats.
Pigments; Stain and Paint
Pigments are the costliest component in paint. Besides providing color, pigments also impact paint's hiding power - its potential to cover an identical color with as few coats as it can be. Titanium dioxide is the primary 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 more easily.
Paint and Stain Additives
Additives regulate how well a paint contacts, or wets, the surface. 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 streaks have a chance to smooth out. That's why oil-based paints tend to drip on vertical walls 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 brought on 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 few hours. This really is no longer the case with better paints, that can be opened and used right from the shaker without threat of pin holing.
Coalescents help latex resins bond, especially in colder weather. Oil-based paint, because it dries slowly and resists freezing, can adhere and dry in conditions from 50°F to 120°F. With added coalescents and, contrary to popular belief, antifreeze, some latexes can be applied in the same temp range, and even lower. Some exterior latexes can be securely 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 be applied in lower heat. 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 breakdown of any covering. It fades colors, dries paint, and increases 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 greater reflection of the sun's rays.
If you live in a region with a lot of humidity, rainfall, 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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