Teak Deck Care

Teak is a beautiful and unique wood in the manufacture of boat building and accents such as decks, handrails, ladders, trim, etc. Some of its most endearing features include an outstanding grain structure, its imperviousness to rot or decay, and being virtually insect free due to the internal oily nature of the wood.

Although the surface feels dry, its oily content repels water, adding another reason teak is the first choice for outdoor use. When oiled properly, the wood takes on a golden glow with an accentuated grain structure that has an appeal to just about everyone. Some prefer to let the teak weather to a soft gray tone that blends with its surroundings while most people tend to keep it looking like new. Both approaches have merit and will not harm or degrade the wood as long as the oil is replaced periodically. Obviously, keeping the wood looking like new is more work, but maintaining its natural golden beauty is the basic reason to admire this fine wood.

Since the oily content of teak is what helps make it virtually impervious to the elements, correctly replacing that oil is paramount in maintaining the wood, especially when kept in direct sunlight. The UV rays in sunlight are what break down the wood's oils, causing it to turn silver gray. In addition, as the oil is depleted, the grain structure opens allowing moisture in that will eventually mildew and turn the wood much darker or even black.

The secret to beautiful teak is a consistent maintenance regimen. Long lasting professional looking results can be achieved by following a few basic steps in caulking, cleaning and applying the correct amount of teak oil:

Caulking Teak Deck Seams

A gorgeous looking teak deck with perfect black seams all has one thing in common, proper preparation and maintenance.

Seams must be perfectly cleaned and prepared before filling with compound. To prepare the seam properly, first remove all the old caulking. One tool is a bent screwdriver that has been filed down to a point, much like a can opener. It should be bent at a 90-degree angle. After the material has been thoroughly removed, it is wise to rout out the seam to provide a clean fresh edge. This step may or may not be necessary depending on how well the old caulking came out. Minimum joint size is 1/8" wide by ¼" deep.

After cleaning and routing, the seams must be washed out with a good oil free solvent. Acetone is excellent for this purpose. This process will dry up any surface oil from the end grain of the exposed teak.

When using a one-part caulk, the seams must be first primed. This will seal the end grain from any escaping oil that will impede adhesion. Do not use a paint product such as red lead. These products are laden with oils that will produce the opposite results you are expecting and the caulk will not stick to the teak.

The next step is to mask the seams with masking tape. It is a tedious task but will eliminate the need to sand the deck after the caulking cures. It, it is important to get the tape right to the very edge of the seam but not go down into it. If you are not careful, the tape will be caulked over and when removed, the tape will rip out the sealant covering it. Just run the tape over all the deck surfaces getting it good and flat. Now you are ready to apply the caulking. You are now ready to apply the material. Cut the tip of the nozzle, puncture the inner seal, place the nozzle at the bottom of the seam and push the gun away from you along the base of the seam slowly while squeezing the trigger. Do not pull or draw the gun towards you. By pushing the gun away from you, you are forcing the material into the seam. If you pull the gun toward you, you will trap air and produce air bubbles in the seam. Next, take a spatula or putty knife and smooth out the seam against the tape. Remove the tape immediately. The result is a perfectly caulked seam.

If sanding is needed, allow the material to cure first. Do not walk on the freshly completed seams until they are fully cured. The caulk should be cured and ready for any sanding in approximately 7 days depending on temperature and humidity. When sanding, sand with the grain and do not use an oscillating type of sander, as it will tear the material loose.

Now treat your seams right. Do not clean the deck with two part liquids and do not coat your teak with fancy teak treatments that may attack the caulking. Products that could be used are:

Cleaning

Teak should not be cleaned with the overly aggressive two-part acid type teak cleaners. The two-part cleaners do clean the teak but also have a tendency to eat away the light colored soft grain of the wood, leaving the darker colored grain and the overall surface with a rough, washboard effect. Some suggest using a stiff bristle brush for cleaning teak, but this too leaves the surface with the same rough condition. If the teak has been coated with some other type of sealer, teak coating, or varnish, it must be removed before any cleaning and or oiling can occur. Another method used to clean teak is pressure washing, which will also very efficiently remove the soft grain.

Before teak can be given any coating, it must be completely clean. 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 3m Scotchbrite(tm) pad and scrubbed across the grain. Scrubbing with the grain tears the soft grain out of the planks, leaving the surface rough. A rough, weathered deck exposes more of the wood to environmental deterioration. Leave the mixture on the wood for several minutes to give the detergent time to suspend the dirt and the bleach time to lighten the wood, and then rinse the wood thoroughly brushing it to clear the grain.

Or use Oxalic Acid powder dissolved in water at a ratio of a half-cup per gallon of water. Increase the strength of the solution, in fact, super-saturate it by using HOT water and adding until no more will dissolve, and apply quickly. Use a 3m Scotchbrite(tm) pad and scrub in the direction of the grain. NEVER scrub your teak with a brush, and avoid sanding if you can.

If the teak is still dark or stained after it has dried for 24 hours follow with an application of 4 ounces of oxalic acid crystals dissolved in 1 gal. of warm water in a non-metallic container. Oxalic acid is the active ingredient in most single-part teak cleaners. Oxalic acid will also dull paint and fiberglass and damage anodized aluminum, so wet down surrounding surfaces before you start and keep them free of the cleaner. Spread the oxalic acid evenly then scrub it with a 3m Scotchbrite(tm) pad then let it sit for a few minutes to work. Rinse the oxalic acid thoroughly brushing the wood to clear the grain.

Commercial cleaners can also be used. Let the cleaner do its work for approximately 10-20 minutes while slightly agitating several times in between. Next, thoroughly rinse with clean water and let dry. Once the wood has dried for 24+ hours, the color has stabilized, and if acceptable, the wood is ready for oiling. However, if the color is darker than expected, repeat the cleaning process. Products that could be used are:

In between, the cleaning and sealing of the teak a middle step may be desired. After the wood has thoroughly dried for 24-36 hours, the color may not be as light as desired. It can be lightened further by using a teak brightener. Some boat owners use a teak brightener after the cleaner and before applying teak oil, because the teak brightener bleaches teak up to a lighter shade and will remove any residue left in the grain from the cleaning process. This step in the sequence of teak care is optional, depending on the owner’s preference. Mid season, if you care to spruce up your teak, apply a teak brightener. It will clean up dirt and grim and give your teak a sparkling appearance and will not attack seam or bedding compounds. Just finish with a light coat of oil or sealer. Products that could be used are:

Teak, after teak has just been cleaned, looks beautiful especially since it takes on a golden color. There are many varieties of teaks from different parts of the world. Some are light grained and almost reddish in color; while others are wide grained and golden. However, once cleaned, all teak has had its natural surface oils removed. If left unattended, it will very rapidly return to its oxidized, grayish look, and more importantly, it will soil easily. Therefore, the teak should be sealed with teak oil.

The most important issues with oiling are to first use a top quality teak oil containing tung oil and a variety of other wood oils. Next, it is imperative to have the oil penetrate as deep into the wood as possible, which does a better job of sealing out moisture and keeps the wood looking great for a longer period. Note: multiple coats of oil will penetrate deeper into the wood. A single coat of good quality oil may look fine for a very short period but quickly begins to oxidize and finally will finally turn the wood silver. Teak oils will generally last from four to six weeks under normal conditions. They last longest in spring and fall when there are fewer hours of harsh ultraviolet light.

Before purchasing any teak oil, it is very important to determine the preferred final color of teak. Generally, there are three-color blends of oil: light, standard golden and dark. All are the same teak oil with color being the only difference.

The correct method to apply oil is by hand. Wipe the oil onto the wood, with the grain, using a sponge brush or rag saturated in oil. This will help to 'squeegee' the oil into the wood and let stand for 3 to 4 hr. or even overnight. This allows the wood time to absorb as much oil as possible. Then wipe off the excess oil with a clean DRY rag. If the excess oil is not wiped off the oil will begin to cure on the surface, becoming sticky, and may never dry properly. Applying two more coats of oil following the same procedure allowing the wood to dry overnight.

After the final coating of oil, the wood should be dry and a beautiful golden color that should last for several months depending on the amount of sunlight (UV rays) on the wood. In higher latitudes, such as Connecticut through Maine and Canada, the wood's color will last much longer than lower latitudes such as Florida or the Caribbean. Re-oiling the wood before it totally turns silver gray will eliminate the extra cleaning and brightening step, saving much time and effort. Products that could be used are:

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 boat owners. Teak sealers are much like oils, but they contain a higher percentage of solids. The solids usually provide protection against ultraviolet light. This means sealers build up faster on the wood and generally last longer than oils.

Sealers do not 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 with three applications of oil. After oiling wait at least two weeks to let the resins dry before you apply the sealer.

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 product manufacture instructs you otherwise, apply sealer using a sponge brush. 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. Products that could be used are: