Now that all the framing members are sanded, it’s time to finish them. Clare and I have been looking into natural finishes for Nerdwood, and rather than use polyurethane, we decided to use linseed oil, which is an oil derived from flaxseed. It’s a drying oil, meaning it soaks into the wood, then dries slowly to a hard finish. It also yellows and darkens somewhat over time, which is desirable in a semi-rustic house, in my opinion. The only real drawback we’ve read about is that it’s not a very tough finish, and doesn’t resist abrasion very well, which makes it unsuitable for finishing, say, a floor, or your in-home bowling alley. That’s not really a problem for the posts, beams, and joists we are using it on; we’ll be unlikely to be doing balance beam routines or walking on the ceiling.
This picture shows the difference between finished and unfinished wood; the beam on the right has been finished with linseed oil:
It’s still much lighter than before we sanded, but the grain is really accentuated. The can of linseed oil contains dire warnings about rags soaked with linseed oil spontaneously combusting, since the drying process is exothermic. I’ve taken precautions with the rags I’m using, but it doesn’t seem like they get any warmer than room temperature. I am mostly using a paint roller to apply the stuff, and a brush to get into tight areas.
You may notice that I am once again using a respirator. The linseed oil itself smells very pleasant (think Murphy’s oil soap, which is also flax-based), but it’s fairly thick and needs to be thinned with mineral spirits before applying it. I’m using “odorless” mineral spirits, which are anything but – not only do they smell, they can make you lightheaded if your ventilation isn’t sufficient. This respirator is rated for VOCs (volatile organic compounds) and I can’t smell a thing when I have it on.
After a number of days sloshing oil on wood, I’m done finishing everything. The picture at the top shows how nicely the saw marks and grain are brought out by the oil. Each joist and timber has it’s own character, just like every log in the walls is different.
The next thing to do is some carpentry necessary to install the floorboards on the second floor. Meanwhile, Clare is working hard on the garden and the harvest has been very good indeed, not to mention the blossoms cheering up the place.