Use and Care Manual

California
Redwood
Association
2/01
405 Enfrente Drive, Suite 200
Novato, California 94949
Telephone [phone]
Fax [phone]
Toll Free 888 Cal-Redwood
www.calredwood.org
Redwood
— our renewable resource
Finish Restoration
Dirt and Dust may build up to the point
that a mere rinsing with water from a
hose will not remove them. A mild deter-
gent and warm water will generally re-
move stubborn dirt and grime.
Mildew appears as dark spots or gray,
fan shaped spots on the wood surface.
Severely infested areas may appear uni-
formly gray or black. To remove a mild
case of mildew, scrub with a mild
cleanser or detergent. Next rinse with a
household bleach to kill surviving spores.
Lastly rinse with water. When applying a
new finish, be sure it contains a mildew-
cide. Note: Household bleach should
never be mixed with detergent containing
ammonia. Fumes can be fatal.
For severe mildew infestations, scrub
with a stiff bristle brush using a solution of
one cup of trisodium phosphate, one cup
of liquid household bleach and one gal-
lon of warm water. Rinse thoroughly. If
necessary, follow with an application of
4 ounces of oxalic acid crystals dis-
solved in one gallon of warm water in a
non-metallic container. Apply evenly with
a soft brush. When wood dries, rinse with
water. Caution: Oxalic acid is poisonous,
but not dangerous if precautions are
taken.Wear rubber gloves. Avoid contact
with skin or eye.
Nail Stains are an unsightly problem that
can be avoided by using stainless steel,
aluminum or top quality, hot-dipped gal-
vanized nails.The cleaning method de-
scribed above for removing heavy mildew
stains is suggested for nail stains.To help
prevent recurrence, countersink the nails
and swab the holes with a water repel-
lent. When dry, fill the nail holes with a
non-oily wood filler for natural finishes,
or putty if the wood is to be painted.
Paint Peeling, blistering and flaking
occurs when moisture under a non-
breathing film finish destroys the film’s
adhesion to the wood. A properly
installed vapor barrier is the recom-
mended way to control this problem.
Vapor barriers should be on the warm
side of the wall. Problems also may be
caused by faulty surface preparation, or
the use of incompatible materials.
Restoring Redwood’s Color
Discoloration of paints and finishes may
occur when extractives are dissolved in
water and leach from the wood.This
discoloration can also result from
moisture migrating to the surface of
unseasoned lumber. To remove extrac-
tive stains and to restore the new
appearance to weathered wood, follow
these steps. Scrub wood with a bristle
brush and a solution of one cup tri-
sodium phosphate (TSP) and one cup of
household bleach to a gallon of water.
Then apply a solution of 4 ounces oxalic
acid crystals dissolved in one gallon of
warm water. When wood dries, rinse
thoroughly with water.
Removing Finishes
When a finish has deteriorated to the
point of cracking and peeling or some
other finish ailment, it may be desirable
to remove it before refinishing.
Sanding effectively removes pigmented
stain finishes. Galvanized nail heads
should be set below the surface before
sanding to protect the coating and
prevent nail stains.
Water blasting is an effective way of
removing old finish and grime and
preparing for a new finish. A fine, high-
powered spray effectively removes loose
materials without damaging the wood.
The use of a paint and varnish remover
is another way to remove a finish.
Several kinds are available. Before
using, test the preparation on a piece of
new, clean redwood to make sure it will
not discolor the wood—particularly if a
natural finish is to be used. Film-forming
finishes can be removed with a paint
and varnish remover. Heat is another
method of paint removal.