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A RATIONAL APPROACH TO THE BEAUTIFICATION
AND PROTECTION OF WOODEN WINDOWS

Compliments of FINE PAINTS OF EUROPE® company founder John Lahey


Although most of our clients are concerned with the appearance and protection of older homes, we are frequently contacted by owners of new homes experiencing chronic exterior paint failure. It is important to know that this problem can be solved.

Manufacturers of wooden windows and doors face a serous predicament - the long term “quality” of their product is frequently determined by the coating system used to beautify and protect their materials and workmanship. In many instances, window and door manufacturers have little if any control over the quality of the coatings used and the manner in which they are applied. It is in the best interest of window and door manufacturers, specifiers and homeowners that all parties be familiar with the specific characteristics required of a fenestration painting system.

RISKS INVOLVED
The three greatest threats to a wooden window are ultra-violet radiation, moisture absorption and fungal spores.

Ultra-violet Radiation: New unpainted wooden windows are extremely vulnerable to damage resulting from ultra-violet radiation which rapidly breaks down the lignin binding wood cells together. UV radiation produces a fuzzy texture in unprimed/unpainted wood, which is an ideal environment for damaging microbes. It is absolutely critical that new windows be properly primed on all surfaces (interior and exterior) before such windows are installed and/or exposed to direct sunlight. We recommend a Hollandlac or ECO paint system on new windows. Under optimal conditions “all six sides” of every wood component will be primed by the manufacturer before assembly. Paints are far more effective than varnishes or semitransparent finishes in repelling ultra-violet light, therefore, we do not recommend clear coatings on exterior wood.

Moisture Absorption: Window manufacturers must take great care in selecting their raw materials to guard against the effects of moisture absorption before and after manufacture. Wood with high levels of moisture (greater than 15%) is extremely vulnerable to fungal damage leading to rot and discoloration. Wooden windows with high moisture levels create adhesion problems regardless of the quality of the coating used. Moisture absorption will also affect the dimensional stability of a wooden window which often results in operational difficulties.

We strongly recommend that window manufacturers utilize a moisture meter to test both raw materials and finished windows prior to the application of coatings. The inexpensive device will produce accurate empirical evidence of moisture content.

Fungal Spores: Although fungal spores do not directly lead to wood damage, their presence on the surface of a window prevents the release of internal moisture. High levels of internal moisture in turn will ultimately create an ideal environment for fungal rot which can rapidly diminish the strength and appearance of a wooden window.

In order to properly protect a wooden window, all surfaces of the window and frame must be uniformly encapsulated with a coating system possessing at least 120 microns of dry film thickness. This encapsulation procedure may be accomplished by brush or spray application. Prime prior to glazing for optimal results.

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* Pro Tips *
Always prime bare wood before applying caulking