wooden windows and doors face a serious 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.
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.
In order to obtain a 5-mil thickness, it will normally be necessary to
apply a system of four (4) coats of FPE finish. Typically, this 4-coat
system will be comprised of one of the following combinations:
Two (2) coats Hollandlac or ECO Primer/Undercoat
Two (2) coats Hollandlac Brilliant or ECO Brilliant or Satin
Two (2) coats Hollandlac Primer/Undercoat
One (1) coat Hollandlac Brilliant in selected color
One (1) coat Hollandlac Satin in identical color as Brilliant
One (1) coat Hollandlac or ECO Primer/Undercoat
Three (3) coats Hollandlac Brilliant or ECO Brilliant or Satin
Four (4) coats *FPE Marine Yacht Varnish - Four coats is the absolute
minimum, although we prefer to see six (6) coats. Be aware that first
class boat yards apply 18 to 24 coats on new work. We do not recommend
the use of varnishes on the exterior of windows and doors unless clients
are prepared to maintain the finish with an annual "dress coat."
The windows and doors must be maintained in the same manner as marine
brightwork - neither practical nor inexpensive.
Two (2) coats ECO Primer/Undercoat
Two (2) coats ECO Brilliant or Satin
*Please note that we do not recommend the use of clear finishes on the
exterior of windows and doors. In situations where a clear finish is absolutely
required, we suggest a full *FPE Marine Varnish System (minimum of four
coats), which may be finished with one coat of *Eurothane Satin or Matte
Varnish if a lower gloss is desired. In the event that clear finishes
are used on the interior of windows, they should be applied in a minimum
system of three coats.
**For information on Marine Yacht or Eurothane Varnish please contact