Inside our dwellings we’re surrounded with beautiful finishes… by wood furniture, cabinets, millwork, as well as other wood items and without much thought we simply expect them to last a lifetime.
The finished wood things we've got outside are lucky. They’re exposed to the extremes of solar radiation in the sunshine… wetness in the forms of dew, rain, and snow…. high temperatures… freezing cold… fungal strikes… and in some instances foot traffic. Great exterior completes protect the wood from these conditions that are harsh, but will surely fail unless they're renewed on a scheduled basis. Care is a must for outside wood finishes.
Choosing an Exterior Wood Finish There are a number of outdoor wood finishes with properties and different characteristics. To pick the best one, you will need to fit the product together with the project and make some choices too. All these really are concerns and the crucial variables to find the top finish;
⦁ Function – Which finish is the most suitable choice for the project you are focusing on? For instance, the finish you are using on your own deck is not necessarily the best option for your new solid mahogany entry door.
⦁ Life Cycle/Maintenance – some finishes last more than many others, but none last eternally. How often have you been prepared to wash, scrape, and/or sand and recoat the finish (i.e., weeks, months, or years) and how simple do you need the maintenance and repair process to be?
⦁ Look – should the finish be clear and bring out the beauty and depth of the wood, lightly coloured and semi transparent, opaque like paint, polished (shiny), matte (dull), or look “natural” – almost undetectable so that it’s not apparent the wood has a finish?
⦁ Application – Given a choice, should the finish be relatively easy have you been prepared for a product that requires more work and advanced skills or to utilize?
⦁ Price – How significant is the cost?
Unfortunately, no finish scores well in most categories – you have to choose a product that fits you as well as your job the very best. There’s take and give in the selection process – for instance, the finishes which might be most easy to use and maintain don’t continue as long as the ones and others that last longest are more work and more expensive. The one thing they all have in common is that they should be recoated every so often to keep up their protective qualities.
Is a Finish Really Necessary? If you want the appearance of silvery gray weathered wood, you might be contemplating leaving your endeavor bare and avoiding the time and expense related to applying and maintaining a finish. The climate is right along with in the event the wood is naturally resistant to decay, there’s the weathered look will be developed by an opportunity leaving it bare in time. There’s a better chance the wood turn black and green, grow mildew, and will get filthy.
Weathering and Decay In the outdoors, bare wood is ruined by the forces of weathering and decay. Weathering alone is a slow, deliberate process. Exposure to sun and water erodes the top layer of the wood. The grain raises as it erodes and cracks and checks grow causing the surface to become rough. The cracks start to become and grow bigger as the boards cup, twist and warp – pulling or eroding away from fasteners. Colour will be changed by the roughened surface and collect grime, notably on the horizontal surfaces. As shown in the picture, this is a slow procedure and produces outcomes.
Decay is due to fungus and breaks down the wood much faster than weathering. Mildew is an airborne fungus that lives such as wood, dirt, and pollen on organic substances. In most of the U.S. the climate has the right combination of heat and dampness that enables mildew to prosper. In the event the wood remains moist, it'll attract and sponsor other fungi and grow rot. In climates which might be primarily cold and dry, decay is much less common or non-existent.
Decay Resistant Wood Species Finished or bare, the most effective wood for outside projects is the heartwood from a species that resists decay. Some woods that match the description are accoya, catalpa, cedar (Spanish, western red, asian white, or Alaskan yellow), chestnut, cypress (old growth is greatest), ipe, juniper, locust (black), mahogany (Honduras or African), mesquite, mulberry, oak (bur, white), redwood (old growth is best), sassafras, teak (old growth is best), walnut, yew, and pressure treated lumber.
United with an outdoor wood finish that is correctly maintained, these species will look great and last a very long time outdoors. All outdoor wood finishes fall into two general classes – permeating picture and finishes forming finishes. Let’s investigate properties and their features.
Penetrating Finishes Strengths ⦁ Don't blister and peel
⦁ Do not need certainly to be scraped or sanded – they wear away
⦁ Allow the wood dry and breathe out
⦁ Easiest to use and recoat
⦁ Most natural looking
Weaknesses ⦁ Offer little protection from soil and wear
⦁ Desire care more commonly than other products. Penetrating finishes usually last three months to your year on horizontal surfaces and double as long on vertical surfaces.
⦁ Tend not to bring out beauty and the depth of the wood
Penetrating finishes are got to soak into the wood surface and seal it from water. They usually do not offer any protection against wear and only a bit protection in the sun, if any. Nevertheless, penetrating finishes would be the simplest to employ and preserve and come in a variety of formulations that includes water repellents (WRs), water repellent preservatives (WRPs), colored WRPs, teak oils and tung oils, and semi transparent stains. Producers appear to be blurring the lines between these finishes which can allow it to be challenging to discover what exactly is in the can. An overall rule of thumb is the more natural looking the finish, the less protection it offers and more frequently it is going to need to be revived.
Exterior Paint
Paint offers the longest lasting protection – it seals the wood from microbial and water attacks and obstructs the UV fully. It’s a great option on doors, trim, and wood siding in addition to outside furniture that doesn’t get wet too commonly. Trimming and siding needs to be caulked to prevent water from getting behind the paint and inducing it to peel off and blister.
The ingredients of paint would be the clear finish (called a binder), pigments, and additives. A thin film is formed by the binder on the surface of the wood and serves as the adhesive that holds everything together. The color is provided by the pigments and make the movie opaque which blocks UV. And additives like biocides enhance longevity and the operation of the paint. The film forming the rate of moisture transfer slows into and from the wood, but the wood remains vulnerable if it’s exposed to the states that encourage decay. It causes blistering and peeling when water gets trapped behind a film.
The most suitable choice for outdoor wood paint is acrylic latex. Top quality acrylic continues longer than oil-base paint as it has better resistance to UV. Acrylic latex can also be more porous than oil-base which lets the wood lose and breathe water. Lastly, acrylic latex is more flexible than oil-base paint and doesn’t become brittle and crack.
NOTE: When painting horizontal surfaces, or any perpendicular wood near a horizontal surface, it’s a great thought to apply a water repellent preservative (WRP) a few days prior to the paint (make sure it’s one that may be painted). By protecting it from the water that splashes on the ground, door jamb, or window jamb causing rot, this may extend the service life of the wood.
Be sure to sand the wood before applying the primer to make sure you get good adhesion. Without sanding wood that’s longer or weathered for a day should not be painted. Follow the primer with two coats of paint in compliance with the maker’s directions. You’ll understand it’s time to get a new layer when the paint weathers away as well as the primer begins to reveal. Don’t repaint too frequently too avoid making it too thick.
Teak Oil, Tung Oil and Tung Oil Finishes
Teak Tung Oil, Oil and Tung Oil Finishes This type of exterior wood finishes brings out the color of the wood gives it a natural appearance for a brief time (before it begins to weather and turn gray). They have been popular since they are simple to use and refresh (though the wood groundwork will require some effort should you wait too long between maintenance cycles). The products that are larger quality have to be refreshed every 3-6 months determined by the exposure and climate states. The lower quality products will need to be refreshed more often. In cases where the finished things are under cover from your elements, the finish may be expected to survive more than it would with direct exposure.
Teak oil will not come from teak trees – it’s only a name producer’s use for a form of outdoor finish they make. Because teak wood is decay resistant, it’s a popular choice for outdoor furniture and boat decks and trim. As an outcome of the woods’ popularity, finish makers developed various products for the marketplace and named them Teak Oil. Similar products include Antique Oil Danish Oil, and Velvet Oil. Such as the water repellents, some Teak Oil finishes feature a tiny amount of pigments to aid them continue a little longer.
Tung oil (and linseed oil) is a vegetable oil that consumes oxygen and crosslinks to form polymers. Because it converts to a [rubbery] solid when exposed to the air, Tung oil is classified as a drying oil and can be used as stand penetrating finish indoors or as an ingredient to manufacture oil-base varnishes and oil-varnish mixtures. When cooked to make oil-base varnishes, drying oils are fully transformed and the end product is a lot stronger.
By itself Tung oil when used outdoors and supplies almost no durability and protection from the sun, water, or wear a milky color turns and becomes food for mildew. It’s the better option when formulating outdoor varnish because Tung oil is more water repellent than linseed oil. Determined by the product, dehydrated castor oil may be seen by you . It’s a synthesized drying oil with similar properties minus the discoloration (yellowing).
Teak Oil and Tung Oil finishes are usually a combination of drying oil and varnish along with some additives to greatly help protect the wood from sunlight and fungus.
Solid Colored Stains
Solid colored stains fall between paint and semi-transparent stains in terms of protection. They have binder and more pigments when compared to a semi transparent stain but are thinner than paints and have to be recoated more often. The advantage they offer is they're easier to apply and recoat than paint and because they are much less thick they enable a number of the natural feel of the wood to show. Like paint, waterborne acrylic stains possess an extended service life than oil-base stains.
Solid colored stains shingles, shakes, and certainly are a great alternative for cedar siding, deck rails and posts, fences, and outdoor furniture. Note that applying stains requires a great technique to prevent creating lap marks (stripes).
Semi-Transparent Stains
Semi transparent stains have the similar ingredients as water repellent preservatives (WRPs) together with the inclusion of a substantial amount of inorganic pigments (clay and soil up rocks) which alter the woods’ natural colour. The pigments aren't affected by ultra violet (UV) light and do a great job of blocking it from your wood. The less UV that gets through to the face of the wood, the less damage it can cause (that’s why paint does such a great job).
The pigments (and preservatives) are held in place by a thin resin (called a binder) which behaves like glue. As the binder breaks down over time (largely from UV damage), the pigments wear off and increasingly expose the wood surface. Ultraviolet (UV) light from your sunlight damages the wood by breaking down the lignin. Lignin functions as the adhesive that binds the wood fibers together and provides the wood its natural colour. Silver grey turns and erodes, as the lignin breaks down.
When inorganic pigments are ground exceptionally fine they allow visible light to pass through making them virtually invisible. Nevertheless they may be large enough to block. These pigments are either crystalline iron oxides (transoxides) or titanium dioxide. The pigments help to protect the binder in the stain which keeps the pigments in place longer and prolongs the service life of the mildewcides and preservatives.
Top products are relatively pricey though price is not a guarantee of functionality. Top quality ingredients – preservatives, resins, and pigments are necessary and costly for maximum longevity.
Semitransparent penetrating stains perform best on weathered wood or coarse sawn like wood siding or on deck and fencing railings and posts. They're not an excellent alternative on the walking surface of decks where people walk, due to the fact that they show wear trails. They ought to be power washed or wetted and allowed to dry a couple of times before staining to open up the pores if used on smooth fence boards.
In the event the wood is dirty or has mildew, clean it well before applying the stain (use a deck cleanser – not soap). In case the wood is weathered but clean, you can put on the stain with no preparation (unlike paint).
Practice the instructions on the can and put on the stain using a brush, spray, or roller. The directions may require in the event you take advantage of a roller or sprayer – that’s to make sure that the stain is worked into all the cracks and crevices that you back brush. Cool overcast days are best for applying stain so it has a chance to soak in before it dries.
Fireproofing spray for wood
Water Repellents and Water Repellent Preservatives
Water repellents (WRs) (note – not waterproof) and water repellent preservatives (WRPs) leave the wood with a natural look (it may not be clear the wood has a finish – especially a few weeks after it’s used). They can be clear/transparent and help to cut back warping and splitting by limiting water absorption. The standard ingredients for WR finishes are a drying oil or varnish resin, along with a solvent, paraffin wax. The solvent helps resin and the wax soak to the top layer of the wood before it evaporates. Adding a mildewcide and/or wood preservative to the mixture causes it to be a WRP and protects the wood. A paraffin oil is used by some WRPs as the solvent which also functions as the preservative. The non-drying oil makes the top layer of the wood greasy for a time. Several of the newer WRPs to the market contain a tiny amount of pigment that adds additional protection and a little color.
To help decrease the level of volatile organic compounds (VOCs) released into the atmosphere, a number of the more recent finish formulas derive from waterborne technology. It’s a waterborne finish, in the event the directions say to thin or clean up with water. A drawback of waterborne finishes is they don’t soak to the wood in addition to the solvent based finishes which causes them to form an extremely thin film on the surface.
Some WRPs may be top coated with paint (check the label) and help maintain the wood better in relation to the paint alone. It’s a great choice on horizontal surfaces and the first few vertical feet (e.g., painted window frames, door frames, and doors).
Water repellent preservatives (WRPs) are the finish of choice for wood decks. They're brushed on wet and specified time to soak to the top layer of the wood before the excess is wiped off. The end grain of the wood will soak up more than the level grain which includes the advantage of protecting it longer.
Road dust control products
Marine Varnish
Top quality marine varnishes in many cases are used as the “gold standard” for finishes that were clear that were exterior. Because they've been subjected to a lot of water and sunlight, the two biggest dangers to wood degradation that’s. Traditional high quality marine varnishes are formulated with tung oil, phenolic resins, UV inhibitors, and biocides. Varnishes centered on alkyd resins have a tendency to oxidize and neglect too quickly when used outdoors.
More recently, uralkyds (also called oil-modified urethanes) have become popular since they provide greater durability and water resistance and therefore are more affordable. Yet, conventional varnishes are more easy to maintain since they've better adhesion properties and don’t always have to be sanded between coats.
