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Painting
Philosophy
I am becoming evermore dissatisfied
with the accepted and standard scraping methods of paint preparation
on historic buildings. I have developed what I am bold enough
to consider to be a superior system. I have come to believe so
strongly in this system that it is now the only method of preparation
that I include in my restoration proposals, and I will no longer
be willing to do a standard scrape. Please Take the time to read
and understand detailed explanation below to understand my methods
and reasons.
Specifications for paint prep for historic old buildings usually
talk of “scraping
to refusal”. Refusal of what? I ask myself. Scrape until no more old paint
can be removed? A worker can remove any and all paint, no matter how sound, if
they are willing to take forever and keep sharpening. Scrape until the workers
are disgusted and refuse to scrape any more? Let’s face it. No matter how
diligent and professional workers may be, human nature is such that “scraping
to refusal” means one thing at 9 AM on the first day of scraping, and something
else at 4 PM on the fifth day. I have never seen a job or specifications in which
the issue of sufficient preparation is quibble proof. I consider myself to be
the most aggressive of scrapers, but can I declare with certainty that I have
removed every piece of old paint that may be at risk of detaching from its substrate?
Of course not. Nor can anyone else who does a standard scrape job. Usually, no
one has any idea what the accumulated layers of paint are. This is why when “scrape & paint” jobs
begin to fail, the failure is usually the old paint falling away from its substrate,
taking the newer coatings with it. So then another “scrape & paint” is
done, and some of the loosening material which the scraper should now remove
is missed due to the fact that it is hidden behind the last coat of paint. These
missed areas will then be the first to fail as before, thus perpetuating this
frustrating cycle. Furthermore, as evermore layers of paint are applied over
the decades, the thickness of the coating increases, meaning that an ugly and
crooked ghost line will show through the finish paint where an area scraped bare
meets old paint. We are all real familiar with this horrid look on old buildings.
The answer is of course to “feather” these transitions with sand paper.
This is often as time consuming a process as the scraping itself, and is a bad
practice from a lead safety standpoint. When all is said and done, no matter
how good a job of preparation may have been performed, the final results still
depend on the old layers of buried paint. In most cases, no one even knows what
these layers are. Dartmouth College, which is known to be demanding of the trades
it hires, only expects 5 years from its exterior paint jobs on historic wood
buildings.
We have begun to use a mechanical method of total paint removal that at first
blush seems barbaric but in my strongly held opinion results in a superior product.
We use pneumatic needle scalers to pulverize the old brittle paint. The scaled
paint can then be easily scraped off and the wood wire brushed. The surface left
by this process is excellent for accepting and holding paint.
Needle scalers are like miniature hand held jackhammers that, instead of one
single bit, have twenty 1/8" diameter needles. The wood surface is rendered
bare, clean, and appropriately coarse. Once the steeple is free of all the old
coatings, one may start fresh with carefully chosen products.
Of course this method of preparation costs more than the standard scraping, but
the difference is not prohibitive. I usually enclose pricing for each method
for comparative purposes. We have used this method on the Pittsford Congregational
Steeple, the Brandon Baptist Steeple, The Waitsfield UCC Steeple, Washington
County Court Clocktower., and the Stowe Helen Day Arts Center among others.
When the paint on a steeple begins to look bad, and money is scarce, church members
often decide to do a quick painting just to “tide it over”. The realities
explained above often put me in the position of urging churches to resist the
inclination to do a “quick” paint. Quick paintings usually mean bad
preparation, and that just makes the endless cycle worse. My recommendations
to wait are often met with incredulity, but I believe strongly in breaking the
cycle, even if the building must look a bit shabby for a few years to do so.
Our standard process for painting is as follows. All wood is coarse sanded. This
sanding is critical since a smooth glossy surface can lead to primer failure.
All products are Sherwin-Williams best. First we prime with A-100 primer cut
with penetrol, then we sand the primer. We then caulk with lifetime urethane
caulk. This caulk is a bear to use but is the best. Two acrylic top coats finish
the job. All coats are brushed in hard, with extra care taken to prime endgrain
wherever practical. We even use putty knives to get the primer into cracks when
appropriate. On new work we prime all wood all round and caulk it into place
during installation. Not infrequently on restoration work, we remove the original
wood for repair and priming, and reinstall as described above.
We believe that the methods explained above result in superior results. Please
let us show you the pictures to prove it. |
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