Wood finishes for all wood doors
I’m looking for feedback on the best finish for exterior fir doors. I live at 7000 feet in the high Sierra and my doors will get rain, blistering high mountain sun and 10 feet of snow stacked against them. Don’t bother telling me I should have used clad doors. The home is a Craftsman style new home with Simpson divided light doors. Should I use an oil? A varathane of some sort?
Replies
I would suggest either a moisture curing urethane, or one of the newer exterior waterborne exterior clearcoats.
Neither of these is an off-the-shelf item, unless you are going to a fully-stocked paint jobber that sells to the trade.
And don't let anybody fool you into thinking you need some kind of penetrating coating. You need a crosslink-cured film, one that has proven use in exterior applications, will stand up to your UV exposure, and has proven longevity.
Spar varnishes look wonderful when applied, but IMHO, they are for guys with boats and lots of mahogany to dress up, who either can recoat each year because they have the time to, or have the bucks to hire it done.
Call Simpson or visit http://www.simpsondoor.com
They have a brochure that explains their PERFORMANCE series of exterior doors made "for tough exposures"
On the back of the brochure, they have a Care & Finishing section that explains everything. Failure to follow their instructions may affect how they deal with potential warranty issues.
"Kinky for Gov. of Texas"
You didn't specify clear or pigmented.
At 7000 feet with sun exposure, I'd use an oil-based primer over clear water-repellent sealer, followed by 2 coats of acrylic latex house paint. The under system resists water entry and the pigmented acrylic resists the sunlight.
If you want clear finish, stay away from polyurethanes. They like to delaminate from the wood in big sheets under UV stress. I have had good success with phenolic/tung oil spar varnishes. Clear will need more upkeep than properly done paint. Pigments are your friend in high altitude solar exposures.
I lived for 15 years at 8300 feet and got to see a lot of failures from sunlight. Deep overhangs are your best friend anytime you are coating exterior woodwork.
Bill
Bill, thanks for your email. I forgot to specify that I want the clear grain fir doors to remain clear. 4 of the doors are underneath gables but 2, including one french door is very exposed and even facing south/southwest which is where the snow storms come from up here in the Sierra. I knew they would eb high maintenance when I put them on the plans.
Do you have any favorite brand of spar varnish?
You will have frequent maintenance needs for certain. The exposed doors get double-teamed by the sun and the rain/snow. I have had good experience with McCloskey's Man O'War and with Waterlox products. Check the web sites of both companies, as they make a lot of different products.You will want an exterior rated product for sure. I have never seen a polyurethane varnish that was good in the sunlight, but I'm not saying it is impossible. I always look for phenolic/tung oil as the base.Another critical issue with doors is to pay extra attention to the joints and soak lots of thin finish into the inside corners where stiles and rails meet, to soak into all that end grain so water cannot do the same. It makes a huge difference.Bill