THE PURPOSE OF STAINS AND PAINTS
Nearly 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 bed room wall. The full 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 coating of skin. What it can do depends on a variety of factors, including the quality and kind of paint or stain, and 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 reduced spattering. A quality interior stain or clear finish should resist fading, peeling, or yellowing, and also be easy to maintain, free of impurities or waxes that could collect dirt and make cleaning or recoating difficult. Outside paints should dry with a toughness that resists deterioration from all types of exposure, and an elasticity that allows for constantly expanding and contracting areas. With their deep penetration and level of resistance to ultraviolet (UV) light, the stains and finishes on your home's exterior should give a similar high performance.
Historical Development 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 might be wondering why these cave paintings have lasted a large number of years as the paint on the south side of your house is peeling after only three winters. Here's why: The frequent mild temperature, humidity, and dark interiors of caves are ideal preservatives. Your home, on the other hand, is exposed 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 mixed with Earth and flower dyes to paint images which may have lasted thousands of years. The Egyptians used asphalt and pitch to preserve their paintings. The Romans later used white lead pigment, developing a formula that could 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 complex varnishes such as, shellac, turpentine, copal, and mastic. The formulas and applications for those varnishes also evolved 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 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 needs to be coated with a wax or varnish, and is very durable.
Created 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, are still a preferred brush for oil-based paints.
Pigments originally originated from anything that bore a color, from ground up Egyptian mummies to pasture mud. Most mineral or inorganic pigments originated from rust, potassium, sea salt, sulphur, alum (aluminum), and gypsum, along with others. Some extravagant works incorporated valuable stones such as lapis lazuli. A huge selection of organic pigments from plants, insects, and animals constructed 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 printed in 1773 was reprinted 14 times until 1900, with only minimal revisions. However, the colder climates of northern Europe have brought about the need for more durable paint, and in the 1500s the Dutch designer 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 harmful. Paints and varnishes were usually mixed on site, in which a ground pigment was mixed with lead, oil, and solvents over sustained high temperature. The maladies that arose from poisonous exposure were common amongst painters at least until the late 1800s, when paint companies commenced to batch ready mixed coatings. While contact with poisons given off during the mixing process subsided, contact with the harmful materials 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 discover a replacement for the natural pigments and dyes that came from Germany. They commenced to synthesize dyes. Today many pigments and dyes are chemically synthesized.
Enhancements in the painting industry have extended well beyond pigments. Water-based latexes have gained in attractiveness as a safe, quality option to oil-based paints. Latexes have changed from simple "whitewashes" to highly advanced coatings that can outlast oil-based products. Both oil-based and latex coatings are emerging every year with noteworthy improvements, like the ground metal or glass that's now added to reflect harming UV light.
A milestone in the evolution of coatings occurred in the very early 1990s with the introduction of a fresh class of paints and stains known as "water borne." Created by the need to adhere to stricter regulations, water borne coatings decrease the volatile organic chemical substances, or VOCs, within standard paint and stains. Poisonous 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.
THE MAKE UP OF PAINT AND STAINS Paints and stains contain four basic types of substances: solvents, binders, pigments, and additives.
Binders and Solvents
Solvents will be the vehicle or medium, for the materials in a paint or stain. They regulate how fast a covering dries and how it hardens. Water and alcohol are the key 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 durability. The expense of paint is dependent in large part upon the quality 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 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 include a greater amount of acrylic resins for higher hardness and durability.
Alkyds and oil-based paints are simply the same thing. The word alkyd comes from "alcid," a mixture 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 powerful combinations such as two part polyester-epoxy for commercial 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 swell hardwood grain and require sanding between coats.
Stain and Paint Pigments
Pigments will be the costliest ingredient in paint. Besides providing color, pigments also affect paint's hiding power - its ability to protect a similar color with as few coats as is possible. 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 more easily.
Additives; Stain and Paint
Additives determine 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 marks have more time to level out. That's why oil-based paints have a tendency to run on vertical surfaces more than latexes do.
Latex paint has been trying to catch up with oil-based paint over the years. 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 induced when the soap wetting agent rises to the top 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 out of 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 stick 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 outside latexes can be securely applied at temperatures 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 heat. As the wetting agents have been removed, the latex dries faster.
UV blocking chemicals have been put into paints and stains to help slow deterioration. 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 which makes paint crack and peel. UV blockers in paint may consist of finely ground metals and ground glass which is currently being added for increased reflection of the sun's rays.
If you live in a region with tons of humidity, rainwater, and insects, you may want 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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