Surface
Preparation Important When Painting Iron and Steel
If
your home is like most, there's at least a little wrought iron
or steel around, and more than likely, some of it could use
a fresh coat of paint. Should you be thinking about painting
something made of these "ferrous metals" here's what you need
to know: First
and foremost, meticulous surface preparation is a must when
painting ferrous metal. Anything less may seriously compromise
the appearance and durability of the finished paint job ...
and eventually, the integrity of the metal itself.
Rust
is the main concern, of course. It can begin to form almost
immediately when ferrous metal is exposed to rain, snow, or
any other type of moisture, and as much of it as possible
should be removed before painting iron or steel.
On
smaller jobs - lampposts, railings, swing sets, and the like
you can remove heavy rust and loose paint with a chisel-style
scraper, then eliminate the rust residue by wire-brushing.
On larger jobs, power wire-brushing equipment (e.g., an electric
drill with a wire brush attachment) or a disk sander can be
used. While you may not be able to eliminate all traces of
old rust, remove as much as possible before applying a primer.
Whether
you use hand tools or power equipment to remove rust, be sure
to wear personal protective equipment in the form of gloves,
goggles and an appropriate dust mask.
After
wire-brushing, remove all remaining particles of metal and
rust before applying any coating. This can be accomplished
as follows:
-
brush off loose particles with a soft-bristle brush;
-
scrub the surface with a detergent and water solution;
-
rinse the surface thoroughly with clean water.
Do
not skip surface preparation just because the iron or steel
surface is new. Even if it isn't visible to the naked eye, some
rust may be present and it must be removed as described above.
Also, new metal may have mill oil on it; before applying any
coating, this should be removed by scrubbing and rinsing.
Priming
is especially important when painting ferrous metal. Not only
will it help prevent corrosion and rusting, but it will also
help the paint adhere to the surface.
However,
it is very important to use the right type of primer on iron
and steel. Experts at the Paint Quality Institute recommend
that you use a high quality, acrylic latex or oil-based, corrosion-inhibitive
primer when painting these surfaces. If you use another type
of primer, rust could reappear or form quickly.
Be
sure to prime the metal promptly after removing rust and other
impurities, making sure that the surface is completely dry.
This timing is vital because rust can begin to re-form on
the metal if the surface is exposed for as little as a day
or two! If that happens, you'll have to repeat the surface
preparation.
Select
a top quality acrylic latex paint for metal surfaces. These
coatings are more durable than ordinary paints and have excellent
resistance to fading. For the best performance, apply two
coats of paint, unless the manufacturer's label suggests otherwise.
Primer
and paint should always be applied to ferrous metal in thick
coats for optimum durability and maximum rust resistance.
If
you take the time to do good surface preparation, prime the
surface promptly, and apply thick coats of the right type
of primer and paint, you can often get eight to 10 years of
service from a ferrous metal paint job. So, don't hesitate
to undertake these projects - but be sure to do them correctly!
For
more information on paints and painting, visit the Paint Quality
Institute's Web site at www.paintquality.com.
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