We did not paint our barn (see my post Don’t Paint — Gray is the New Green ) because it is sided with 1-inch slabs of white oak, which has weathered to a silvery gray and will not rot.  But we do have to paint our house in town, which is not made of oak and has proven itself very willing to rot in more than one area.

We also have to paint the old windows that we have found for the barn so they will last, and that has meant using paint, starting with a coat of good primer.

Yesterday was one of those crazy days where we  spent the morning fixing up our house in town to sell next spring and the afternoon restoring the old windows we are putting into the barn on our land.

Both projects involved priming.

Of course, whatever color we paint, it will be greener if we do it right so it will last, and that means priming bare wood with an undercoat that the scientists at paint companies have created.  According to Wikipedia, wood is very porous and will absorb the solvent from paint, drying the paint prematurely. Because most paints undergo chemical reactions during the process of curing (for example, latex and alkyd-based paints actually polymerize when curing), they depend on water or solvent being evaporated slowly rather than being absorbed quickly by the underlying material. A layer of primer will help the paint to undergo proper complete curing cycle.

Also, wood – even when it is painted – is still vulnerable because paint is slightly water permeable. is exposed to moisture, a thin layer of paint will still be water permeable.  Primer increases  the waterproofness of the paint.

Paints coat wood like glue, and if you are lucky, they will stick for a long time.  Primer is formulated to be the stickiest possible paint, sticking to both the wood and the paint coat that covers it, but evidently, it’s important to read the can and paint over the primer as soon as the can says its o.k.  The sooner you cover the primer with finish paint, the better the bond.

So today I get to do the fun part and paint the barn-red final color over the primer now sticking like a tick to our restored windows.  Then they will go into this wall, and complete the barn’s finestration.  (Don’t you love that word?)

..The windows will go up here.

For the record, we are priming with Sherwin-Williams Duration.   On the label, it states it has “Patented PermaLast Technology,” but we bought it anyway.

According to several online reviews, building professionals posting on Internet forums call this the best exterior house paint.  Comments by professionals and serious do-it-yourselfers indicate a preference for Sherwin-Williams Duration on message boards such as ContractorTalk.com, PaintTalk.com, DIYChatroom.com and PainterForum.com. Two other sources, JoePullaroInc.com and iHomeline.com, also recommend Sherwin-Williams Duration. About.com’s guide to home repair, Bob Formisano, mentions Sherwin-Williams as a good paint brand.

I find Sherwin Williams logo which features a giant paint can floating in space and spilling its contents all over the earth to be more than a little disturbing, so if you have a paint you like better, please let me know.