Loft Joists and Danish Oil

As you may have noticed in the June 18 post, when I installed the loft ledger boards there were joist hangers already attached. Those ledger boards, glued and bolted to the wall, are there for the sole purpose of holding the loft joists--the structural skeleton of the loft--and the galvanized steel joist hangers are how that connection is made. 

Cutting three pieces of 2x6 the correct length and nailing them into a joist hanger is not that much to write home about. But things got a little interesting due to the fact that these joists--like the ledger board--will be exposed. 

Before I installed them, I of course shou sugi ban'ed the 2x6s. Of the four total joists, three are Douglas-fir and the fourth--the one facing the room--is a lovely piece of clear cedar that I recovered from my grandfather's scrap pile. Grandpa passed away earlier this month, so I decided to put that particular piece of wood on display in his memory. It's the Grandpa joist. 

The Grandpa joist is fully burned and scrubbed, but the Douglas-fir joists are lightly burned to match the ledger boards and the one joist that I installed at the same time as the ledger boards. 

But I wanted to make the wood look a little more finished, and I wanted something that would sort of seal in the burnt wood. Even with a light char, the wood leaves smudges if you bump or rub it. At the same time, I wanted as natural an appearance as possible--no glossy varnish, please! 

I chose Danish oil for my finish. Danish oil is a hardening oil made from linseed (flax) oil; it soaks into the wood and gives it a richer color. You can buy it in various colors--oak, walnut, mahogany, etc.--but I chose the uncolored "natural," which just lends a warm, slightly reddish cast to the Douglas-fir. The basic application technique is to flood the surface of the wood with oil and let it sit for a half an hour, then wipe on another generous coat and give it 15 more minutes. Then--the fun part (sarcasm)--you take an entire roll of paper towels (or more!) and wipe, scrub, buff, rub the wood until all the oil you possibly can is removed. What remains is what soaked in, where it will harden up over the next 24 hours and provide a durable but natural-looking finish. 

If you don't wipe, scrub, buff, rub the wood enough, instead you'll get a sticky finish that will attract dust and cussing for the rest of eternity. So wipe, scrub, buff, rub... 

I didn't take pictures of the application process because Danish oil is not the kind of thing you want to accidentally smear on your camera/phone--cleanup requires paint thinner. There were a lot of drips and rumpled up paper towels lying around, though, trust me. The result, however, was awesome! 

Update: I later used Danish oil and lightly burned Douglas-fir on another project, so I can show you the before-and-after effect on the wood:

Before: light shou sugi ban, bare wood

After: shou sugi ban, Danish oil finish

Nice, isn't it? On these ones I got distracted during the 15-minute waiting period and left it too long, so it was considerably harder than it should have been to wipe, etc., the excess oil off. It had already started to set up. After an initial wipe-down of the most egregious excess, I ended up taking the torch to it again and wiping off the oil that liquified and bubbled from the heat--repeating until it no longer bubbled. It worked decently enough and barely darkened the wood beyond the tiger-stripe effect I was going for. 

 One last note: I did not apply Danish oil to the Grandpa joist. I experimented a little with shou sugi ban cedar and Danish oil and decided that it darkened the wood too much and actually decreased the warm tones that were present. Besides, the fully burned and scrubbed cedar looked gorgeous as it was and since I'd scrubbed it so thoroughly, it didn't smudge much.