Editor’s note: In this column, Steve Maxwell answers a reader’s question about finishing outdoor wood in cool weather.
Q: How should I seal and protect a cedar planter I just built? I’d like the wood to stay light and bright outdoors. The weather is getting colder, though, and I’m concerned that there won’t be enough time and warmth to let a wood finish dry properly.
A: Your hope of keeping the cedar looking bright is a common one. The challenge keeping any outdoor wood looking new is that all finishes deteriorate over time and stripping certain (but not all) finishes back to bare wood can be a big pain. In your case, the cool, wet weather at this time of year adds complications.
One excellent option I’ve used for keeping bright wood looking bright outdoors is exterior finishing oil. I know from experience that Minwax Teak Oil works well outside (that’s what you see above) and, like all exterior oils, it forms no surface film. That’s a good thing because it means you won’t need to invest lots of time and trouble stripping off an old film-forming finish such as flaking, failing varnish or urethane.
Over time, oiled wood begins to look thirsty and that signifies it’s time for another application of oil. Typically, an annual re-coating of oil after brushing off the dirt and cobwebs is all that’s required.
On the downside, oils don’t provide as much protection as, say, an outdoor varnish. Even with regular re-application of oil, your planter will get progressively darker over the years.
Is it possible to store your cedar planter indoors during the off season? This will help any finish last longer and the wood stay brighter. Even keeping the planter in a shaded location during the summer season will help it stay looking good longer.
Sunlight, not moisture, is the most damaging part of outdoor exposure when it comes to wood finishes.
Another option is treating your planter with something called Ecowood Treatment. I like this stuff a lot and have been using it on my own projects for years.
It makes the wood age and weather evenly. This is a less formal look than the Teak Oil, and essentially you’ll have something that looks like refined barn board after a few years.
Your wood will last just as long as if it had a protective finish, but it will be less formal looking while requiring virtually no maintenance. Here’s a sample board I made up for a photo:
In the video below, you can see me applying Ecowood Treatment to some new cedar shingles I installed on an old shed. The bright, new cedar looks fabulous, but I know from experience that, in a year or two, uneven weathering will make the shed look bad. A consistent grey colour is much nicer and it’s quite enduring.