Pre-Prime Wood for longer lasting paint

by admin on June 7, 2012

Pre-priming on all six sides of a piece of wood is a pertinent step when installing and/or painting, and dramatically improves the long term durability of a pint finish. Since Fine Paints of Europe was founded in 1987, the company has continuously condoned the tested, traditional way of priming exterior wood on all “six sides” before painting and/or installation. Note that the only primer that works for this is a high-quality alkyd primer, like the oil primer that Fine Paints of Europe carries.

Fine Paints of Europe Oil Primer is used by many manufactures and restorers of high quality doors and windows who encase their products with Oil Primer before painting and/or shipping.

Using an Oil Primer on wood at proper moisture levels guarantees:
o A coating which will not allow moisture penetration in or through the wood. This creates“dimensional stability” and forgoes paint failure created by moisture from any source (including interior moisture) from entering the wood.
o A substrate that’s perfect for all future coatings no matter if they’re solvent or water borne, alkyd or acrylic.
o UV light will not harm properly primed wood. Many contractors and homeowners don’t know that unprimed wood will lose a significant amount of the hair like lignin which allows coating to adhere if it is exposed to direct sunlight for as little as two weeks. This damage cannot be fixed and the wood’s ability to “hold paint” will be significantly reduced for its lifetime.
Almost all commercial window manufacturers and lumber mills that offer pre-priming use waterborne primers. Waterborne primers are cheap and dry quickly but unfortunately they also conceal the quality of the wood from homeowners and contractors. Poor quality finger -jointed wood is hidden with the unsuitable waterborne primer. Many window manufacturers will not sell unprimed windows because they want to hide the quality of the workmanship. Low quality finger-jointed wood is easily concealed with an inexpensive waterborne primer. We suggest buying an unprimed window as you will get a much better quality one than if you bought it pre-primed.
Recommendations
1. Premium custom windows and doors often come pre-primed with oil priming. These windows and doors come from shops that focus on quality and wish to produce a hundred year window. They want to make sure that their clients are taken care of no matter what happens in the process. These are usually done with exotic woods like mahogany that don’t accept water borne primers. Adhesion is also better with a solventborne alkyd primer. These will cost about $3000 per window and $5000 per door. Investing only $10 to $15 per window in Oil Primer is a good move. High quality custom shops in America have been using Fine Paints Oil Primer over fifteen years.
2. Don’t be fooled by cheap, pre-primed pine windows from large manufacturers. Many times these are pre-primed to hide the poor quality of the wood. They cost on average between $1000 and $1200 each. Contractors and homeowners that insist can get special orders of medium priced unprimed windows. This lets you prime bare wood properly with an Oil Primer and complete it with Hollandlac or ECO before you install it in your house. After installation the second and final coat of paint should be applied to both exterior and interior. A properly primed pine window that is encapsulated will last fifty (or more) years with repainting every 10 to 15 years. With a waterborne primer that same pine window won’t last twenty – and the homeowner will be repainting every couple of years. If you purchase a pre-primed window you can sand it to the bare would and re-prime with Fine Paints Oil Primer. Careful not to scratch the glass!
3. Oil Primer is especially important on wood siding. We recommend western red cedar or eastern white cedar (no spruce or pine) and that each piece is encapsulated with Oil Primer or ECO primer and get one coat of ECO on both sides before nailing in place with stainless steel nails. Heavily priming end cuts with the same primer used before nailing in place is crucial. End cuts is typically where moisture will get in. One tiny opening can result in total paint failure in as little as a few months.

When working on siding and shingles, note that there is a risk associated with having alkyd primed or painted wood come in contact with other alkyd primed or painted wood; in fact, these pieces of wood will bond together as if they were made of super glue. Alkyd coatings can even take several weeks to cure and two pieces of alkyd primed siding can bond together ninety days after priming if not separated by furring strips, shims, etc. This is one more reason why it is impractical (or even, impossible) to properly prime siding with an Oil Primer in a factory environment. Siding should always be delivered raw to the job site and placed in an area with shade or covered with black plastic before priming in order to avoid UV damage and picking up moisture. Siding should be purchased and tested upon delivery to meet a 12% or less moisture spec.
A labor conflict in 1903 between carpenters and painters affect how we use pre-primer today! Until 1903 it was the carpenter’s purview to coat all 6 sides of the wood in pre-primer. They wouldn’t consider using wood without this crucial oil based moisture barrier. Then a labor dispute resulted in painters being responsible the application of all coatings, including pre-primer. Since then this practice has mostly stopped. Less than 2% of new residential construction has the benefit of back priming and encapsulation. Unless the homeowner insists, it usually doesn’t happen.
Back priming with a porous, waterborne finish doesn’t accomplish anything. Waterborne paints (with the exception of waterborne alkyds, like Fine Paints of Europe ECO) have a high perm rate and will not offer you protection.

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  • Bill Perkins

    Good site, Bill Perkins Perkins Precoat Stoughton Mass

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