Teak Care
by Don Casey
In clean air untreated teak weathers to an attractive ash gray, but
where most boats live, the assault of modern-day air pollutants quickly
turns bare teak nearly black. Scrubbing tends to leave behind an unattractive
mottled look, neither golden nor gray. Most boatowners eventually find
themselves unhappy with either look and decide that some treatment is
essential.
Paint provides the longest lasting protection but it hides the wood.
If we want the natural beauty of the wood to show, we must apply a clear
coating. The choices are oil, sealer, or varnish.
Cleaning
Before teak can be given any coating, it must be completely clean. Your
expensive teak is literally dissolved by strong cleaners, so always
use the mildest cleaner that does the job. A 75/25 mixture of liquid
laundry detergent (such as Wisk) and chlorine bleach may be adequate,
perhaps boosted with TSP (trisodium phosphate). Apply this mixture with
a stiff brush, scrubbing lightly with the grain. Leave it on the wood
for several minutes to give the detergent time to suspend the dirt and
the bleach time to lighten the wood, then rinse the wood thoroughly,
brushing it to clear the grain.
If the teak is still dark or stained when it dries, a cleaner with oxalic
acid is required. This is the active ingredient in most single-part
teak cleaners. Wet the teak and sprinkle on the cleaner. Spread it evenly
with a Scotchbrite or bronze wool pad, then give it a few minutes to
work. While the wood is still wet, scrub it with the Scotchbrite pad
or bronze wool. (Never, ever, ever use steel wool aboard your boat-it
will leave a trail of rust freckles that will be impossible to remove.)
Oxalic acid will dull paint and fiberglass and damage anodized aluminum,
so wet down surrounding surfaces before you start and keep them free
of the cleaner. Rinse the scrubbed wood thoroughly-brushing is required-and
let it dry completely.
Two-part teak cleaners are dramatically effective at restoring the color
to soiled, stained, and neglected teak, but these formulations contain
a strong acid-usually hydrochloric-and should only be used when gentler
cleaning methods have failed. Wet the wood to be cleaned. The cleaner
will dissolve natural bristles, so use a nylon brush to paint part one
onto the wet wood. Avoid getting the cleaner onto adjoining surfaces.
Remove the dissolved surface by scrubbing the wood with the grain with
a stiff brush or a Scotchbrite pad.
Part two neutralizes the acid in part one, and it usually has some additional
cleaning properties. Paint a sufficient amount of part two onto the
teak to get a uniform color change, then scrub lightly. Flush away all
traces of the cleaner and let the wood dry.
Oil
Oiling teak on boats is a time-honored tradition. Oil intensifies the
colors and grain patterns of wood and gives the wood a rich, warm appearance.
Because it simply enhances the inherent beauty of the wood-more like
salt than sauce-oiling is arguably the most attractive of all wood finishes,
and it restores some of the teak's natural oils and resins. Unfortunately,
the benefit of oiling exterior teak is extremely transitory. The sorry
truth is that teak will last just as long if you don't oil it-longer
really, since repeated between-coat scrubbing wears the wood away. But
oiling teak isn't about protecting the wood; it's about recovering and
maintaining that golden glow that made us want teak on the boat in the
first place.
Teak oils are primarily either linseed oil or tung oil, bolstered by
resins to make them more durable. Linseed oil tends to darken the teak,
but it is significantly cheaper. Tung oil doesn't darken the wood, and
it is more water resistant than linseed oil-a notable advantage for
boat use. However, a month or two after application, it may be hard
to discern that much difference since both oils carbonize in the sun
and turn dark. Proprietary teak oils address this problem with various
additives, including pigments, UV filters, and mildew retardants. Some
that perform admirably in one climate are reviled in another. If you
are going to oil your teak, make your teak oil selection based on the
recommendations of other boatowners in your area.
Apply teak oil with a paint brush. Immediately wipe up (with a spirits-dampened
cloth) any drips or runs on fiberglass or painted surfaces, or the resins
the oil contains will leave dark, nearly-impossible-to-remove stains.
Watch out for sneaky runs below the rail.
Oiling requires multiple coats. The wood will initially "drink" the
oil, and thinning the first coat about 20% with mineral spirits or turpentine
encourages it to penetrate the wood more deeply. By the third coat,
oil will begin to stand in some areas. Wipe up excess oil with a cloth.
Continue to brush on the oil and wipe away any excess until the wood
is saturated. The wood should have a matte finish without any shiny
spots.
Sealers
Another approach to achieving a natural look is the application of a
sealer. Durability and ease of application have made some sealers very
popular with boatowners.
Sealers don't feed the wood but, as the name suggests, they seal out
moisture and dirt, and seal in natural oils and resins. Unfortunately,
the oils and resins may already be lost, so the first step in applying
a sealer to old teak is to restore the oil content with a thorough application
of teak oil. Clean and bleach the wood to a uniform color, then oil
it until it refuses to accept more. Now wait at least two weeks to let
the resins dry before you apply the sealer.
After two weeks, wash the wood and let it dry completely. Sealers need
an oil-free surface to attach to, so wipe the wood heavily with a rag
soaked in acetone to remove all oil from the surface. The oil the wood
has absorbed will be unaffected by this quick-flashing solvent. Unless
the can instructs you otherwise, apply sealer exactly like oil. A throw-away
brush is adequate for the job, and brushing technique is not a concern.
Wipe away all excess with a cloth. Apply additional coats until the
surface shows a uniform matte finish.
Maintain sealed wood by washing it and applying a fresh coat of sealer
every two to three months.
Varnish
Aside from its much-admired appearance, varnish offers genuine protection
for the wood. Wood coated with varnish will not dry out and split, will
not absorb moisture and rot, is unaffected by dirt and pollution, and
will be untouched, thus unstained, by oily or greasy spills.
The absence of pigment in varnish means it does not shield the underlying
surface from the sun. Ultraviolet radiation penetrates the coating and
carbonizes the oils in the wood, causing the wood to darken beneath
the varnish. To minimize this effect, varnish makers add ultraviolet
inhibitors-sun screens-to their products. For exterior brightwork, select
a quality spar varnish (not urethane varnish) heavily fortified with
UV inhibitors. As always, get local recommendations from other boatowners
before selecting a specific varnish.
Teak doesn't hold varnish as well as other woods due to its oil content,
but a long-lasting coating is possible with the right technique. Books
have been written about applying varnish. You may not get that perfect,
mirror-like finish on your first try, but as long as the wood is ivory
smooth, the weather is warm and dry, and you don't "worry" the varnish
with too many brush strokes, you should get admirable results. Plan
on applying at least six coats.
For more
information about oiling and varnishing brightwork, consult Sailboat
Refinishing by Don Casey.
|
