Painting The Exterior (continues)
Applying Exterior Paint
Optimal conditions: Because the main cause of failure or
deterioration is moisture, your first requisite for painting is a dry day. Check the label
on the can for the recommended drying time, especially if the weather is expected to
change soon. Wait several days after a rain, and allow morning mists to evaporate before
starting.
Temperature is another important consideration: paint must set before the temperature
drops below 40 degrees Fahrenheit. For that reason, it’s best not to paint within 2
hours of sundown if nighttime temperatures could go below that level. Unusually high
temperatures are a problem as well, because surfaces that are too hot can cause paint to
blister.
The best way to avoid strong sun is to paint in the shade: paint the south face early
in the morning; then the west face, the north side at noon; in the afternoon, work the
east face and any part of the south face that you didn’t finish earlier. Avoid
panting in temperatures above 90 degrees Fahrenheit.
Paint the house from top to bottom, working horizontal sections all the way across,
until they end at window or door trim, or at the end of a wall. This method minimizes
overlap marks. After painting large sections, go back and paint trim, again from top to
bottom. Porches and decks should be done last. If you can easily remove any pieces, such
as storms or shutters, do so; paint them as they lie across sawhorses or lean against a
garage wall.
Priming. Prime all exposed wood. Check the label or the topcoat paint to be sure you
get the correct primer. Alkyd or oil-based primers have better adhesion on smooth, dry
surfaces; but if the outside is unusually rough, latex may be a better choice. Always sand
between primer coats and topcoats.
For bleed-through areas, use sealer-primer; shellac is good for knots and nail holes,
but it must also be covered (when dry) with a primer or a topcoat.
Spar vanish is its own primer coat, as are most other clear, exterior finishes. Thin
the first coats with a solvent, to permit greater soaking into the surface. Sand lightly
between coats. Although some paints (oil and alkyd) may be applied over clear finishes
that have dried, the reverse is not true, for the solvents in clear finishes often
dissolve paint.
Stains do not need thinning; they should be applied full-strength right to bare wood.
Most will not bond, however, to any previous non stain coats. If you have stripped the
house of its original paint, and want to switch to stain, test a small section first.
If you stripped off old paint and now wish to repaint, prime with two coats of
oil-based or alkyd primer. Cut the first coat of primer at least 25 percent with solvent,
for greater soaking and adhesion. Apply the second coat of primer at full strength. After
that, one, or at most two coats of topcoat is sufficient. If is not necessary to sand
between coats of exterior paint.
Where you are working with exposed wood, save some money by using two coats of primer
and one of topcoat, rather than one primer and two topcoats. If the paint manufacturer
recommends only one coat of each, follow directions. Durable paint jobs depend not upon
the number of paint layers but upon the adherence of each layer.
Brushing it on: When possible, mix at the same time all the paint you will need
for completing a job, so the house will have uniform color (or colors) throughout.
It’s also helpful to have extra empty cans, so you can work out of a half-full can. A
full can is a nuisance, and a can that is nearly empty means dredging up the thicker paint
at the bottom of the can. To maintain consistency, add paint frequently to your work can.
A brush’s bristle should be dipped into paint to a depth of about one-third the
length of the bristles. Tap-don’t scrape-a loaded brush against the rim of the can to
unload excess. Paint the undersides of horizontal siding first; then work paint into the
faces. To distribute paint evenly along siding, partially unload the brush by dabbing
every foot or so; then spread out the dabs, working them in with cross-diagonals and
smoothing them out along the length of the siding.
Work all the way across a horizontal section to avoid lap marks. Work about six courses
of clapboard at a time. Where you encounter nails or butt seams, slap in a little paint
and smooth it over, rather than jamming bristle ends into the wood.
Stains apply nicely to natural-wood surfaces with brush pads because a foam pad holds a
lot of stain. The only problem is control: load pads with too much stain and it will run.
Again, paint the undersides of shingle or clapboard courses first. Most stains contain
solvents that are extremely caustic, so wear a long-sleeved shirt, gloves, a hat with a
brim, and safety goggles. Stains are an excellent wood preservative because they are so
tough on living things, such as mildew and insects. The same applies to human skin. Use
them carefully, therefore. Finally, consider spray-painting the exterior.
Painting masonry: Preparing a masonry surface is important. Use a wire brush to
remove loose material. If you find grease or oil on the surfaces, wash it off with a
detergent such as trisodium phosphate; then rinse well. Other, more stubborn substances
can be handled with a weak solution of muriatic acid; wear goggles and gloves, and rinse
well. Fill major cracks and holes before painting, and if there are any moisture problems,
deal with them before painting. Although water-sealer paints are available, none are
absolute protection against serious moisture problems.
Use rollers to apply paint to large masonry areas. Where walls meet floors,
"cut" edges with a brush; similarly, on steps or in cramped areas, use a brush.
For very rough areas, use a 6-in, brush or a roller with a long nap. In either case, apply
paint slowly so painting tools won’t splatter.
Click below for more Information
[Painting The Exterior]
[Surface Preparation]
[Stripping Exterior Paints]
[Applying Exterior Paint] |
