We strongly recommend oil based Marine Varnishes for the exterior finish. Marine finishes have UV inhibitors added which allow them to withstand sunlight much better. Avoid polyurethanes – they are harder, which tends to make them flake off and are more laborious to refinish. You can research “long-chain vs. short chain” varnishes for a more detailed explanation. Under no circumstances should a lacquer-based finish system be used on exterior doors.
Stain is a colorant, not a finish. If you desire to change the color of your product, use an oil based stain. Water based products may raise the grain of the wood. Stains of different colors can be blended to obtain the color you desire. Remember, the finish coats will affect the final observed color, test a sample before finalizing your color selection.
Before applying the first coat of finish or stain, remove all handling marks, raised grain and other undesirable blemishes by sanding all surfaces with 180 grit sandpaper. For doors with shaker sticking, lightly ease the outside edge of the sticking with sandpaper. To avoid cross-grain scratches, sand with the grain. NOTE: small amounts of grease, oil or pitch can be wiped clean with denatured alcohol or turpentine. A “tack cloth” should be used to wipe the surface free of dust and lint.
After applying the stain, allow the recommended drying time before applying the finish coats (varnish).
The first coat of varnish should be thinned by 25% to act as a sealing coat. Subsequent coats may also be thinned, which will allow them to level better and will also allow longer working time. However each coat will be thinner, so extra coats will be required. 3 coats minimum is required.
Sand between coats lightly, and wipe with a tack cloth before applying the next coat.
The final finish coat should be run onto any glass/wood interfaces by 1/16 of an inch. This will insure that the interface is well sealed against water and snow/ice.
Once again, all 6 surfaces – the 2 faces and 4 edges should be finished before the wood is allowed to be exposed to moisture.
Having the product lying flat will greatly reduce the chance of runs or sags in the finish.
Use disposable foam brushes to minimize marks.
Very fine 3M Scotch pads rather than sandpaper will help minimize dust.
Purchasing varnish from online marine suppliers will both save money and will most likely be newer stock, which will dry better.
Painting or varnishing your doors and windows will do much more than make them look more attractive. The wood we use has been kiln dried to a very specific moisture content that has been researched to be the optimum level for stability and strength.
Finishing when properly performed, keeps the wood at that moisture level. Warping, swelling, twisting and other movement of a finished wood product indicates that the wood has increased in moisture. Similarly, wood decay is a series of fungi that requires the wood to nearly triple in moisture from its kiln dried state, to begin growing. ”Dry rot” of wood is a misnomer – wood decay fungi cannot grow if the wood is dry.
Proper finishing is defined as 3 coats minimum on all faces and edges, before exposure to the elements. This will preserve the state in which your new windows and doors are delivered, and will protect your investment for generations!
We are advocates of oil-based paints for all wood products.
Specifically, finishes for marine use are the most protective wood finish.
In Pennsylvania, the EPA has limited purchase of oil based house and trim paint to quart quantities. If there is no suitable replacement for an oil based product, it can still be purchased in larger quantities. For example, oil based primer is available in all quantities, because it seals wood resins which latex/acrylic does not. If you ever see wood with brown rings or spots of resin bleeding through the finish, this is an indicator that all latex products were used. Finish paints such as industrial enamels can be purchased in gallon and larger quantities, as latex/acrylic is not an acceptable finish for steel (the moisture goes through the paint, and steel will rust underneath). Likewise, marine enamels are available in all quantities – again, latex/acrylic is not considered suitable protection for marine environments.
More modern enamels such as epoxy and urethane have some outstanding properties. Consideration should be given to what the refinishing requirements may be.
Before applying the first coat of finish, remove all handling marks, raised grain and other undesirable blemishes by sanding all surfaces with 180 grit sandpaper. For doors with shaker sticking, lightly ease the outside edge of the sticking with sandpaper. To avoid cross-grain scratches, sand with the grain. NOTE: small amounts of grease, oil or pitch can be wiped clean with denatured alcohol or turpentine. A “tack cloth” can be used to wipe the surface free of dust.
The first coat should always be primer. Primer is a bonding and sealing coat, it does not offer finish protection.
The next two coats are of the finish paint, which protect against moisture (and give the desired appearance!). Oil based paints will dry quite hard within a week; latex/acrylic paints will stay soft and gummy for 6 to 12 months. This softness may cause windows and doors to stick, and frequently the paint will adhere to weather stripping and sliding surfaces. This will of course not protect the wood as intended, but can also cause operational problems.
The final finish coat should be run onto any glass/wood interfaces by 1/16 of an inch. This will insure that the interface is well sealed against water and snow/ice. Once again, all 6 surfaces – the 2 faces and 4 edges should be finished before the wood is allowed to be exposed to moisture.
A high quality china bristle brush will allow a much nicer finish to be achieved, and will be easier to paint details with.
Penetrol is a paint additive that will give a smoother finish, and has additional benefit claims. Use in the amounts directed, and be aware this product will age quickly once opened so use promptly.