SURFACES
Drywall is made of gypsum that is covered with paper and used mostly for interior
wall and ceiling construction in residential and commercial buildings. Very
porous drywall can lead to peeling if low quality primers and paints are used.
Assuming you have made all the proper surface repairs, new drywall should be
primed with a top quality latex primer-sealer and two coats of quality latex
finish paint. This will provide a good surface for new paint application and
provide a consistent finish throughout. Drywall that is being repainted should
first be primed with a latex primer and finished with two coats of acrylic finish
paint.
Hardwood siding is primarily made from wood chips, cooked with pressurized
steam and refined into fibers. Resins are added to bind the fibers and provides
strength while wax is added at pressing to repel water. Although hardboard siding
is factory primed, it is highly recommended that new hardboard siding be primed
with one coat of a top quality alkyd primer and finished with two coats of a
top quality finish paint. Any cut or exposed areas showing through the factory
based primer should be spot primed during surface preparation.
New masonry is high in alkaline content and can include surfaces like brick,
concrete, block, stucco, cement, and plaster. Testing the pH content of the
mortar and the masonry will indicate if the masonry has cured enough for painting.
The pH content needs to be below 9 before masonry is ready to be primed or painted.
Always check with a local paint dealer or contractor when considering painting
masonry. A salty looking substance that develops on weathered masonry, caused
by moisture, should be scraped off or removed with a wire brush. It is important
to use a top quality primer and paint that is alkaline resistant when priming
new masonry to prevent peeling later. You can insure a longer lasting and durable
paint life by allowing the proper curing time and selecting the proper primers
and paint coatings.
Metal surfaces include iron, aluminum, galvanized iron, steel and wrought iron. New metals can contain surface oils if they have not had adequate time to weather. All ferrous metal surfaces must be free of rust. Wipe all metal surfaces with mineral spirits to remove any oily, greasy residue. Solvent and rags should be changed frequently. If at all possible, let new metals weather for a minimum of six months. If there is no time to allow for weathering, clean with a solvent to remove oil treatments that might be present. Painting over oil treatments will cause adhesion problems. These surface oils can react with paint and cause peeling.
Watch for surface oxidation. Surface oxidation can be cleaned with steel wool. Any rust that appears on metals should be scraped down to bare metal, or at the very least be treated with a hardening chemical. Properly prepared metal surfaces should be primed with two coats of either a top quality breathable rust inhibited alkyd primer or top quality acrylic latex rust inhibited primer and finished with one or two coats of a top quality acrylic latex finish paint.
Mixing of paint for metal painting: Stir thoroughly before and occasionally
during use. Do not add oil colors or solvents. Apply with a quality synthetic
brush, short or medium nap roller, pad, or spray. Do not apply when air and
surface temperatures are below 50° F (10° C).
Exposure to weather conditions, mainly water or the ultraviolet rays of the sun, for more than two months causes wood surfaces to change. The colors of new wood can begin to turn yellow or brown and then to a silver gray. Simultaneously, the surfaces will develop cracks, the wood grain rises, warping occurs, and nails begin to loosen. Whenever discoloration appears, clean the surface with a deck brightener based in sodium percarbonate, and a pressure washer. Let the surface dry for about two weeks, and apply a coat of a top quality water repellent stain or preservative. However, if the weathered look is desired along with the protection, a bleaching oil, bleaching stain, or weathering stain is recommended.
Top quality water repellent stains and preservatives are essential for repelling
water and resisting weathering, and are most affective when the wood is dipped
into them, or the stain is applied with a brush. Homeowners should always be
careful of overstaining. Overstaining will cause the finish to build up. It
produces a film on the wood surface that will eventually peel, blister or crack,
and become waxy and slick. Usually, one coat is all that is needed. If a second
coat is required, make sure the first coat has soaked in good, and wipe away
any buildup or puddles when applying the second coat. All purpose water repellents
and sealers are designed more for masonry, and should never be used on wood
surfaces.
It is highly recommended that new wood be primed and painted immediately. New preservative treated wood can not be painted without proper aging, because the preservatives will react with paints and cause wide spread peeling. Preservative treated wood can be stained with specially formulated preservative treated wood stain. Paints should be applied when the wood is dry.
Woods like redwood and cedar are prone to "tannin bleeding." Tannin
bleeding is the result of natural dyes that extract themselves from the woods.
These dyes are water soluble and will lead to discoloration of latex primers
and paints. Top quality alkyd based primers work extremely well in preventing
this type of bleeding and should be finished with a top quality acrylic latex
finish paint.
Vinyl expands and contracts with the changing weather conditions, and normally
contains a very slick surface. Good adhesion is essential for the smooth and
slick surfaces that vinyl siding provides. Never sand, scrape, or cause any
other abrasions to a vinyl surface. Never paint vinyl darker than the original
color because dark colors absorb heat and could cause the vinyl to warp. Top
quality acrylic latex paints can be applied to vinyl surfaces once they have
been properly washed of debris.
It is not recommended to paint over wallpaper. Painting over wallpaper can cause the surface to form large blisters that may or may not recede, which can cause major surface preparation problems. Wallpaper should be removed with a wallpaper stripper, or vinegar, that has been mixed with very hot water. The wallpaper that is to be removed should be soaked with the solution of choice so the paste under the paper will breakdown, allowing the wallpaper to be removed. Wallpaper steamers are also good for removing wallpaper. Once the wallpaper is removed, the surface needs to be cleaned of any excess paste, repaired where applicable, lightly sanded, and primed with a top quality alkyd stain blocking primer.
The priming is necessary to seal any paste that may have gone undetected. Any
undetected paste that is painted over will react with the paint and cause it
to crack. Homeowners considering a wallpaper project should always prime or
apply a good coat of sizing to the surface before applying wallpaper. This will
allow for easy removal of the wallpaper in the future. If the surface is not
properly prepared before wallpaper is applied, future removal of the wallpaper
and surface repairs will be extensive.
When painting paneling, you first need make sure the surface is cleaned and free of dirt, dust, etc. Then score the surface with sand paper, a sanding block, or steel wool. Caulking and filling cracks is optional but does enhance the end result. Once all of the surface preparation is complete, apply one good coat of a stain blocking primer to prevent the paneling from bleeding through the finish paint. When the primer is dry, apply two coats of your selected finish paint.