August 2013 – What’s In A Paint Job | Shepley Wood Products
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August 2013 – What’s In A Paint Job

Until the middle of the 19th Century, most Americans didn’t have much use for paint. Wood was plentiful, and paint was difficult to make and not very effective as a weather coat. You couldn’t run down to the local hardware store to buy a can of paint because pre-mixed paints didn’t exist. Ingredients had to be purchased separately, and because many were imported, they were quite expensive. Paint had to be mixed pretty much as you used it, as no one had figured a way to give it any kind of shelf life. The worst part was that paint in those days had so little opacity that it took five or more coats to cover the substrate.

Paint consists of pigment (for color and opacity), binder (to dissolve pigment and create a film), and solvent (to allow the paint to flow). Other additives such as driers can be included. The first pigments used were natural ones. Reddish brown iron oxide (rust) was an earlier popular one, as was brick dust. Iron carbonates gave yellow and brown, soot gave black, and manganese dioxide yielded purple. The earliest paints date back to cave dwellers and they used an interesting array of ingredients including blood, animal and vegetable oils, honey, tree sap, and urine. White lead, which was a mainstay of paint production until recent times, was first developed by the Greeks and Romans using vinegar which was the strongest acid available to them in those days.

In New England, paint was looked upon as an indulgent frivolity on a par with fancy clothing, during the Puritan era. In 1639, the Reverend Thomas Allen, of Charlestown, MA was highly criticized because the interior of his house was painted. He was able to redeem himself when he could prove that the paint had been applied by the previous owner. Shipbuilders and carriage builders remained the major users of paint throughout the 18th Century. A measure of the limited popularity of paint is that of the items the British taxed in the 1760’s, we certainly remember the furor that erupted over tea, but are probably not aware that white lead, red lead, and pigments, all used in paint, were taxed similarly. The Boston Paint Party never took place for a reason!

To make exterior paint, one had to boil one pound of red lead and four gallons of linseed oil, then simmer until red froth stopped rising to the top. Boiling and clarifying the oil made it dry faster. Next the pigment had to be hand pulverized in a large mortar and pestle, or similar vessel, until it became a fine powder. Mixing was inconsistent so you can imagine the potential for problems and irregularities. In the 1850’s merchants began to prepare barrels of pre-mixed paint. Customers brought their own containers and usually filled them with enough paint for the days work. In 1871 Henry Sherwin and Edward Williams started the company that bears their name today and paint production began to become an organized industry. Latex paints first were introduced in 1948 and now greatly outsell oil based paints. Paint formulation has changed over the years often influenced by health and environmental issues. Lead based paints while very durable, proved quite hazardous to humans, and were phased out some forty years ago. Government restrictions on emissions of Volatile Organic Compounds (VOC’s) have influenced the development of new formulations that try to balance paint coat performance with environmental concerns.

As I write this, oil based paints and primers still do the best job of holding back tannin bleed found in knots and species like Western Red Cedar. Acrylic Latex paints seem to stand up to the weather better in terms of maintaining coat appearance. Our preference at Shepley is still an oil based(alkyd) primer as a foundation and even a first top coat of oil based paint with subsequent 100% acrylic latex top coats to give you the combination of the holding power of oil with the wearing power of acrylic latex. There is no one product that does all, regardless of claims you may hear. One thing that has not changed over the years....preparation is critical! Any coat of paint is only as good as the surface it is applied to and the conditions it is applied under. Manufacturers have come a long way from the days of home brewed paint but who knows what the future holds for innovation in a very old industry. Remember...when it comes to paint, you get what you pay for. Scrimp now, pay sooner.