THE PURPOSE OF STAINS AND PAINTS

Almost every kind of surface, from drywall to concrete, needs protection from the elements. These damaging elements can range between raging blizzards to innocent looking sunlight on a dining room wall. The total thickness of the paint that eventually ends up outside of your house 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 will depend on a variety of factors, including the quality and kind of paint or stain, and how well the surfaces are prepared and painted.

Paint and stain should be durable, resisting fading and abrasion and allowing repeated washings. Interior paint can go on with minimal spattering. A quality interior stain or clear finish should resist fading, peeling, or yellowing, and also be easy to maintain, free from 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 sorts of exposure, and an elasticity that allows 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.

Historical Development of Stain and Paint

The oldest known paint was employed 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 part of your home is peeling after only three winters. Here's why: The constant mild temperature, humidity, and dark interiors of caves are ideal chemical preservatives. Your home, on the other hand, is subjected to all types 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 mixed with Earth and vegetable 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, making 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 complex varnishes such as, shellac, turpentine, copal, and mastic. The formulas and applications for those varnishes also transformed little during the 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 alternative interior paint. Cassein, the protein in milk, dries very level and hard, and can be tinted with other pigments. Like stains, milk paint should be covered with a wax or varnish, and it is very durable.

Created from hogs' bristles, badger and goat hair, brushes also transformed 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 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, amongst others. Some extravagant projects incorporated precious stones such as lapis lazuli. A huge selection of organic and natural pigments from plants, insects, and animals made-up 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 printed in 1773 was reprinted 14 times until 1900, with only slight revisions. However, the colder climates of northern Europe did bring about the need for more lasting paint, and in the 1500s the Dutch designer 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 blended on site, in which a ground pigment was mixed with lead, oil, and solvents over sustained high heating. The maladies that arose from poisonous exposure were common among painters at least before late 1800s, when paint companies commenced to batch ready mix coatings. While exposure to toxins given off through 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 discover a alternative to the natural pigments and dyes that came from Germany. They started out 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 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 each year with significant 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 early 1990s with the introduction of a fresh 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 materials, or VOCs, found in standard paint and stains. Harmful and flammable, VOCs evaporate as a coating's solvent dries. They could be inhaled or absorbed through the skin, and create ozone pollution when subjected to sunlight.

PAINTS AND STAINS CHEMISTRY

Paints and stains contain four basic types of materials: solvents, binders, pigments, and additives.

Stain and Paint Solvents and Binders

Solvents will be the vehicle or medium, for the ingredients in a paint or stain. They regulate how fast a covering dries and exactly 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 contains binders, which form the "skin" when the paint dries. Binders give paint adhesion and durability. The expense of paint will depend 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 greater amount of acrylic resins for better hardness and durability.

Alkyds and oil-based paints are basically 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 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 revised alkyd for home use. Urethane boosts sturdiness.

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 solid wood grain and require sanding between coats.

Pigments; Paint and Stain

Pigments are the costliest element in paint. Besides providing color, pigments also have an impact on paint's hiding power - its ability to hide a similar color with as few coats as you can. Titanium dioxide is the principal 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; Paint and Stain

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 stridations have a chance to level out. That is why oil-based paints have a tendency to run 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, 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 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 would have to allow it to settle for a few hours. This is no longer the situation with better paints, that can be opened 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 adhere and dry in temps from 50°F to 120°F. With added coalescents and, contrary to popular belief, antifreeze, some latexes can be applied in the same heat range, and even lower. Some outside latexes can be securely applied at temperatures as low as 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. As the wetting agents have been removed, the latex dries faster.

UV blocking additives have been put into paints and stains to help slow deterioration. Sunlight is accountable for a lot of the breakdown of any covering. It fades colors, dries paint, and adds to the expansion and contraction process which makes paint crack and peel off. UV blockers in paint may consist of finely ground metals and ground glass which is currently being added for even greater reflection of the sun's rays.

If you reside in a region with tons 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

Local Painters Lake Stevens

Google Map