Experiences with Woods and Finishes for Outdoor Applications
Issue: Issue 334
Posted Date: 9/10/2013
Our reader feedback this time out focuses on the Q&A section from the last issue of the eZine. In that issue, there was a discussion of "what wood and finish are best for outdoor benches?" Here's another opinion on that subject. - Editor
"Outdoor finishes face a lot of variables. If they're out in the open, direct sun heating and winter freezing will crack a solid finish in a couple of years. Once water wicks under the finish, that's all she wrote: the next hot day steams the paint right off in ugly patches. Outdoor furniture in covered areas are often damp enough that mold, moss and fungus grow sometimes right in or on the paint. No one wants to sit on a chair that is going to get your butt wet and green, but I've seen a lot of lawn chairs that will do exactly that -- if they don't break under you because of hidden rot.
"So, I agree with Chris Marshall and go for the natural finish, if at all possible. An inexpensive 1,500psi power washer will return natural wood to a fresh look quickly. It will also strip some loose paint, but I prefer a more powerful model if that's my goal. Nothing will get into the joints to clean them properly, so they'll always trap moisture. Woods like cedar and redwood shouldn't be painted because their natural oils will push the paint right back off. It turns into a bubbly mess with a bit of sun, and I've seen it come off in strips. Some oil and semitransparent finishes will work, but I keep them thin and they have to be refreshed every few years.
"I built benches for our woods which is full of walking and riding paths. I built them out of red oak fence boards (cheap, available from my neighbor's sawmill, and I have them around anyway for fence repairs.) Not the best wood for ground contact, so I made feet from scraps of treated pine which keeps the oak an inch from the ground. They're not easy to access with equipment. I painted them with two coats of "Tool Handle Mix" -- a homemade 50/50 mix of boiled linseed oil and turpentine with a dash of Japan drier that we've always painted the handles of our shovels, pitchforks and such with. It's a thin coating that sheds water, but still allows the wood to breathe. I just rough sand (80-grit) quickly every three to five years and apply another coat. It's a nice rustic finish and tends to get prettier as the years go on. It darkens with age and near the joints where it doesn't get weathered and worn as much." - Jim MacLachlan
Although the comment below was directly responding to last issue's Q&A on "Ironwood Uses for Woodworking," it also gets into outdoor applications. - Editor
"Re: issue 333 and the comments on ironwood. Actually, the real name is Ipe, but does go by other iterations. It is grown primarily in South Central America, particularly Brazil. It is extremely hard, very difficult to machine, but makes for a fabulous outdoor decking -- and sometimes deck chairs. My neighbor used it for that purpose and it was beautiful and outlasted him, sorry to say. I intend to use it for the same purpose on my outdoor deck. The upfront costs are mitigated by almost no upkeep." - Rod W. Brown