Q: We recently purchased two cabins on the water at Clear Lake (Calif.) that were built around 1950. The property had been derelict for at least 30 years.
Both cabins have redwood siding that appears to have been given a clear coat of varnish or shellac. Most of the coating is gone. The wood is silver/gray and fairly soft. Most of what was left of the varnish has come off as we brushed the wood with a natural-bristle brush. We’re afraid to use a wire brush or power wash because the wood is so soft. Yet certain areas require more cleaning. Should we sand at all?
We like the patina that has developed, but wouldn’t mind enriching the natural color. We do not, however, want a shiny surface.
Will clear preservatives give us a matte finish? Do you recommend any particular product? How often can I expect to have to reapply this preservative? Also, part of one cabin will be painted.
What type of primer would you recommend based on mostly bare exposed wood? And what type of finish coat?
A: These buildings sound like wonderful old structures. Kudos to you for wanting to restore them while maintaining their patina and natural beauty. Thirty years of neglect on the exterior has produced almost a blank canvas for you to work with.
One word of caution, however: The gray patina that has developed over the years is on the surface, so work with a gentle hand to preserve it.
Your instincts are right about using a wire brush or pressure washer to clean the surface. Redwood is soft to begin with, and wind and weather over three decades have made it softer. Using a wire brush almost guarantees that you will remove some of the soft cellulose fiber from the wood, leaving an irregular surface. Being too aggressive with a pressure washer will produce this same unacceptable result.
To clean the fragile surface we recommend that you apply a solution of detergent specifically made for cleaning exterior wood. Avoid products that will bleach the wood. These cleaners are available at home centers in the paint section. Apply the cleaner according to the manufacturer’s instructions and rinse thoroughly using an adjustable nozzle attached to a garden hose.
Try the cleaner on a small, inconspicuous area first to make sure you are happy with the results. If the cleaner doesn’t produce satisfactory results, a pressure washer is the next step. Be cautious, and be sure to use a low pressure and a wide spray pattern. Remove only the dirt and not the patina from the wood.
After washing and cleaning the surface, some light sanding might be required. We’d suggest you invest in a handheld orbital finish sander. These are available at home centers and hardware stores for about $50. Use fine-grit paper, starting with No. 220. If that doesn’t cut fast enough, No. 150 is about the heaviest grit we’d recommend. Use a gentle hand and keep the sander moving to avoid marks on the wood.
Thirty years of neglect has dried out the wood, and it’s important that the moisture be returned to prolong its life. To finish the bare wood, consider using an oil finish. Linseed oil is a good choice. Try the oil on a scrap board and see if the result is what you’re after. It will probably require several coats to produce a uniform finish, but the result will be a rich patina. For the painted portion of the buildings, definitely use an oil-based primer.
An old trick Kevin used when painting Alameda, Calif., Victorians was to add extra linseed oil to the primer. After the primer dries–give it at least four or five days–apply two coats of a high-quality acrylic finish. Wait a couple of days between coats to allow the first coat to dry thoroughly.
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