How To Paint And Make It Stick by Darren G.
Burton
Preparing the surface correctly prior to painting is probably the most
important task in the entire procedure. Varying types of surfaces will
require different methods and procedures for preparation.
This article provides these basic procedures for the most common of
surfaces.
New Woodwork
As all timber is not the same, a different type of primer must be used for
different wood types. Softwoods, such as pine, will require a primer coat
containing more oil. Pine is a rather porous wood and will absorb oil
readily. Hardwoods are very closed-pored and are often greasy when new.
Therefore, the primer for hardwoods must be thinned with mineral
turpentine.
Be sure the timber to be primed is dry enough. Often new timbers are still
quite damp. The timber will probably require a light sanding, followed by
the removal of debris with the aid of a dusting brush. All knots and
resinous veins in the wood should be sealed with a suitable knotting
material, such as a dab of alkyd resin exterior undercoat. The surface can
then be primed.
A healthier and more environmentally friendly alternative is to employ the
use of an acrylic primer. Water-based primer tend to be less absorbent on
porous woods. Also, they don’t emit toxic fumes.
Previously Painted Woodwork
If the surface is in a reasonable condition, it will need only washing and
a light sanding. But if the surface suffers from blistering or flaking
paint, the affected areas must be sanded smooth and spot primed. The
entire defective paintwork must be removed, however, if large portions of
the surface are affected.
The best way to achieve this is to burn the paint off with an LP gas
burner. After burning off, the surface must be sanded smooth, dusted off,
and primed.
New Concrete Work
A new concrete surface should be allowed a minimum period of around three
months to dry out before painting should be attempted.
The surface should be washed with a solution of zinc sulphate and then
sealed with a concrete sealer. This procedure mainly applies to oil-based
paints. Acrylic paint can be applied immediately after the drying out
period.
Previously Painted Concrete
All peeling and flaking paint must be removed. A stiff wire brush
accomplishes the job successfully. A thorough washing down of the surface
will then be required. If the surface is chalky or powdery, a
binder-sealer such as Binderol should be applied.
New-Set Plaster and Fibrous Plaster
Newly-set plaster surfaces should be allowed a drying out period. As lime
is a problem in new-set plaster, a coat of zinc sulphate solution should
be applied as with concrete. If painting with an oil based paint, a
pigmented sealer will be necessary as the initial coat. Acrylic paint may
be applied directly.
Previously Painted Set and Fibrous Plaster
The surface should be sanded and a coat of cement sealer applied before
attempting to paint with an oil or enamel paint. Flaking paint must be
removed and the patches filled with spackle or pollyfilla. If painting
with acrylic, the surface need not be sealed.
New Iron and Steel
A rust-inhibitive priming paint must be applied to ensure thorough
protection of the metal. All dirt and grease should be removed before
priming to ensure paint adhesion. After coating with rust-preventative
paint, the surface must then be coated with a suitable metal primer.
Previously Painted Iron and Steel
If the paint is cracking or flaking, it must be removed by sandblasting or
flame cleaning. If it's only a small job, the use of a paint-removal
substance is all that is needed. Rust must be removed with a wire brush
and the affected areas rust-proofed and primed with metal primer. The
entire area should be wiped clean with a rag dampened with turpentine. A
healthier alternative to the turpentine method is to use a mixture of
white vinegar and water to wash down the surface.
New Aluminium
An oxide coating forms on new aluminium surfaces and this coating
generally protects the metal. This film, however, offers no resistance to
acids, alkalis and salty air. These substances will corrode the surface,
so the surface should be cleaned and slightly roughened employing the use
of steel woo. The primer coat should be zinc chromate. The surface can
then be painted with the selected finish.
New Copper
Copper offers the highest natural resistance to oxidation and weathering
of most metals. However, if situated in a corrosive atmosphere, the copper
surface should be cleaned and slightly roughened as explained with new
aluminium, and primed with a coat of zinc chromate.
Previously Varnished Surfaces
When re-varnishing a surface, it should be cleaned with turps and steel
wool, rubbing with the grain, and dried with a clean rag before the turps
has dried.
If you are planning to paint the previously varnished surface, it will
require thorough sanding and then a coating with a stain-sealing undercoat
such as Bleedseal.
If these preparations are adhered to, the result should always be a
durable and long-lasting painted finish.
About The Author:
Born in Sydney, Australia, Darren G. Burton has been writing for more than
20 years. He has written numerous full length works of fiction and
non-fiction. In addition to his books, he has had many articles and short
stories published in major Australian and international publications.
