Even well finished projects will eventually change color and begin to show damage, like this bear statue. In most cases, when it comes to outdoor woodworking projects, the part that comes in contact with the ground is end grain. While water sheds off the rest of the piece, those end grain surfaces often sit in it, acting like a wick. Porous wood, especially close to the ground, absorbs a great deal of water, which will eventually damage and rot even the best treated wood. As you probably know, wood is made up of hollow cells that look like a bundle of straws when viewed on end. They will hungrily wick up water when furniture feet stand on wet ground. That can create excess swelling and can contribute to premature rot and cracking. Outdoor wear on furniture can be slowed if it is sealed or built from specially treated wood like this Westport chair, but even then damage will eventually seep in. A good finish on the ends or the use of rot-resistant wood will help, but there’s something more you can do, and it’s fairly quick and simple.

Before you apply the finish, plug up those end grain areas with exterior epoxy. The epoxy will soak up into the end grain, creating plugs that stop up those straw-like ends, preventing water from wicking up. Red Persian Cat For SaleThat, in turn, can extend the life of your table and chair legs.Cats Adoption Hobart It’s obvious why this technique works on simple furniture with vertical legs, but I also use it on Adirondack chairs. Hvac Unit Power ConsumptionIn most designs, the bottom of the angled back legs are cut diagonally across the grain. Although they are a bit less prone to problems than full-on end grain, they can still soak up excess water, and it’s a good precaution to seal them. Applying a cure of epoxy, especially to the legs and feet of chairs, tables, and other outdoor furniture can effectively fully seal the wood from the environment.

Since epoxy is inert when cured, it is compatible under exterior finishes, so seal the ends before finishing. Turn the piece upside down before you apply the finish, and make sure the ends are clean. I like to sand the end grain with coarse 80-grit paper to make certain that I have a clean surface with clearly open end grain. Choose a slow-curing epoxy, one with a 12-hour cure rather than quick-set “five-minute” epoxy. You don’t want it to set up before it has a chance to soak down into the pores. Mix a batch of epoxy and spread it across the end grain, pushing it into the pores with a popsicle stick or scrap wood stirring stick. The goal is to get it only on and in the end grain and not on the adjacent flat grain surfaces. Give it a minute or two to soak in, then squeegee off the excess so that the end grain is fully packed and just a very thin coat of epoxy skins the surface. Don’t leave it on too thick or it can chip off. The idea is to impregnate, seal and case harden the end grain rather than apply a surface coating.

Let it cure fully, usually overnight, then sand the sides of the legs prior to finishing in order to remove any wayward epoxy. You’ll find that this simple precaution can measurably extend the life of your outdoor projects.Crystal clear solid extra hard protection with zero clouding due to UV.For many years builders of wooden boats have used a combination of two-part epoxy resins and marine spar varnishes to make "furniture quality" clear-finished watercraft. That these boats look good after several years of outdoor exposure is testament to the synergistic effect of using these products together. The same techniques can be used to protect many wood projects, allowing them to be left outdoors uncovered for months at a time without fear of the finish failing, the wood warping, splitting, or discoloring, and joints coming apart. Common clear wood finishes are usually separated into two types: film-forming and penetrating. They protect and bring out the beauty of fine woods. Film-forming finishes seal the wood to protect it.

Penetrating finishes, usually in the form of stains or water-repellants, allow moisture to move in and out of wood with minimal effect. Outdoor versions of these finishes contain ultraviolet (UV) light inhibitors which enable them to stand up well to the rigors of sunshine. Unfortunately, these finishes are generally poor at excluding both liquid and vapor moisture from cycling in and out of the wood. It is this cycling, combined with degradation from sunlight, which usually causes these finishes to fail. The finish will flake, crack, peel, or simply weather away, and the wood will begin to discolor and split. System Three Clear Coat™ epoxy, combined with either System Three Spar Urethane or WR-LPU Marine Topcoat are the perfect finish system for retaining the natural look and beauty of wood outdoors. The epoxy resin sealer will offer protection from everything but sunlight, and it will bring out the natural beauty of the wood. The spar varnish or polyurethane topcoats will block the sun's rays and provide scratch and abrasion resistance.

Together, these products will give your outdoor wood projects the ability to withstand the elements and retain their "like new" appearance. Other items you may need: Outdoor Wood Finishing Brochure I am starting to make wood furniture for outdoor use. I want to use epoxy to waterproof the wood before applying poly for UV protection. I am looking for references to facilitate my learning. Also, can epoxy can be applied over spar urethane? The epoxy makes a great sealer, but it needs to be protected from UV. This is why you generally need to apply a topcoat over it such as a marine varnish, or urethane, etc.? For particular products/schedules I would check out some of the boat building sites and suppliers. 2K urethanes also have a lot of potential. If this furniture is going to be used seasonally, and/or placed in the shade with minimal exposure, I would try not to go overboard. Keep it simple and use an exterior oil finish that can be reapplied, or stick with a marine varnish or exterior urethane.

Just remember no matter what you do that the UV radiation from sun exposure wreaks havoc on transparent coatings on wood. Regular maintenance will be required. Re-coating every 3-5 years, more or less, will be necessary. Pigmented stains or paints add a tremendous degree of protection. Having worked on both brightwork and custom Adirondack furniture for many years, I would suggest using CPES and a UV inhibited phenolic resin/tung oil varnish. Both are wonderful products for your applications. Why would you want to apply epoxy over spar (urethane?) anything? You're sort of missing the point.My client had this piece built and it was sealed with urethane. Moisture has caused problems. I'm wondering if epoxy can be applied over the urethane so that stripping the whole piece can be avoided. If a varnish (this includes urethane resins) has been damaged by moisture, the only good way to restore it is to remove the coating down to bare wood and re-coat it. If you were to try and just cover up the damage, it isn't repair, it's just obfuscating the problem (and delaying the eventual fix).

When boats are repaired, the wood is scraped and sanded to bare wood. I always seal it with CPES and then water won't be a serious issue again. So what one can do is not necessarily what one should do. It does, however, differentiate professionals from DIYers and amateurs. The problem I have with polys is that they are not very good at inhibiting UV degradation and they have not proven to be very good at standing up to lots of moisture. This is changing as new 2K polymer resins are being incorporated into marine applications. Phenolic resin and tung oil (drying oil) varnishes have been used for a very long time. They are also very good, especially for marine applications. Here's the problem with most spar varnishes (including polyurethanes). They are not true spar (marine) varnishes. I'd say maybe only 10% of spar varnishes (maybe less for polys) are even adequate for their stated/intended use, let alone preferred. So, unless you're up for reinventing the wheel, learn from history and keep an open mind to improvements in materials and methods.

New is not necessarily better. Once you put a barrier coat on an outdoor item, you are chained to it forever, maintenance-wise. Barrier coats for exterior clear finish woodwork all started with boats, and those finishes are designed to be removed entirely and then reapplied regularly. Think about your epoxy/urethane coated pieces and what you will do when given a piece back with peeling epoxy. You will need to remove all of the topcoats of urethane, then the epoxy in any damaged areas - down to new wood, then reapply, dealing with old wood color versus new wood color, etc. Is this something you - or your customer - want to do? This is why the best outdoor furniture is built with oil or no finish, and left to weather. Look at the West System epoxy web site for help. Wood moves, thick epoxy doesn't. Small cracking will happen from this movement or UV failure. Get any small cracking, and you get water under the finish. Then you have the finish failure. If you want clear finish on wood, expect lots of maintenance.

Nothing waterproofs wood - Mother Nature always bats last! I've had good luck with the West System. If you plan on putting a coating over it, make sure you use the 207 hardener. Guys, West System is a marine epoxy, but it is not a penetrating epoxy. Clear Penetrating Epoxy Sealer (CPES) is made to do this, nothing else (other than rebuild damaged sections of wood). I like West, I've used it at least 50 times, but it is good for what it was designed for. It is not a sealer. It makes maintenance much easier and it doesn't come off with sanding. That's where the penetrating comes in. West 105 is called a barrier coating and when applied per spec, it gives a 3-4mil thick coating. Would you like to add information to this article?Interested in writing or submitting an article?Have a question about this article?Have you reviewed the related Knowledge Base areas below? KnowledgeBase: Finishing: General Wood Finishing KnowledgeBase: Furniture: Outdoor Furniture Would you like to add information to this article?

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