joiners’ work; green woodworking

J Jones wrote and asked a leading question the other day. The answer could expand to thesis-length. I will condense it here…

first, the question:

“I wonder if you could show the general timeline of assembly in a project like the joined stool that Brian and Jennie discussed above. The techniques and orientation of the wood planes make sense to me, but I am having a hard time visualizing when these parts should be assembled. How dry should the joints be to prevent splitting?

There are times when you will work on a part, put it aside, then finish it later. I have read Jennie’s writing about fitting chair tenons into their mortises, and how they must be bone dry, yet the mortise can be “air dry.” Are there any such rules or timelines that you follow?”

Now, the answer, subject to additions and clarifications of course…

In joinery, things are different from the chairmaking scenario outlined in Alexander’s book and DVD…

The gist of it (we’ll have plenty of detail on this in the stool book one day) is that this project can be done from the tree quite quickly, but it doesn’t have to be…

two wedges to start the split

Ideally, we split the stock when the log is fresh, i.e. full of moisture. With oak, this can be a long time after felling, as long as it has not been split open. The riving down to rough size and planing take place in this same condition, for ease. It just works so much easier when wet. However, you can’t get a fine, smooth finish with planes, turning tools, carving tools, etc until the surface has begun to dry. So after planing, I stack the boards in the shop (in winter, away from heat source) Shavings piled on them don’t hurt, and sometimes help prevent checking or splitting at the ends. Mostly a problem in thicker stock.

planing green oak
freshly planed oak w shavings

Within a couple of weeks in most situations, the outer parts begin to dry while underneath the oak is still wet inside. This depends greatly on the weather (in my shop, in August, it takes longer to reach this state we have taken to calling “workable moisture content” than it does in mid-winter with the heat on). So at this stage, any finish surface work can take place…the wood still works easier than any store-bought drier stuff and responds nicely to a good sharp edge.

scratch stock & crease molding

The joinery itself mainly requires that the tenon be dry-ish at assembly. If the tenon is too wet at assembly, the pins will not pull the tenon home, they will instead just compress the fibers in the tenon and the joint will not be as strong as it should be. Likewise, the pins need to be dry, any moisture in them & they can shrink upon further drying, leaving the joint loose…

piercer bit for boring tenon

The stool is the simplest joinery project of all, just about. Things like joined chests, large press cupboards – these have more complications, but their construction, the body of them, is the same. Floors, doors = these are things that get complicated. Some period joiners often had many projects undeway at once, for a lot of reasons; but one benefit is that you can leapfrog them along…sit this one aside, bring the next one along, etc. I do this constantly.

We have seen some pictures in the blog of period evidence for our ideas on this aspect of green woodworking. I will in a future post pull some of that stuff together. we didn’t pull this out of our hats, there’s a basis for it.

Those are the main points – remember the blog is the teaser, the book will have the whole shebang….

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12 thoughts on “joiners’ work; green woodworking

  1. Here’s how it works, Kari. We/I have umpteen drafts, a few thousand photographs and too many ideas. I am re-working the draft these days, in the hopes of finishing it in the next month or so. Then choosing a slew of photos, then finding someone nutty engough to publish it…so right now, still writing & shooting. I figure if I keep talking about it like it’s a book, then it will become a book. the race is on, I am bound to do it before Alexander’s trip to the boneyard…
    watch this space, as they say.

  2. This is such a great idea, I will be the first one interrested in this book. Have you ever considered making it into a digital e-book? Could be cheaper and it is a green option for a green project such as yours…

    • well, Tim = yes, we’ve batted it about; but I am too big a fan of real books. I like the web, etc – but as long as I’m living, I will opt for a book in the hand anytime. I hate reading books here…sorry…

  3. Thanks for clearing that up. I imagine that in frame-and-panels, the panels would lay by until they were closer to dry to avoid pushing the frame apart.

    I look forward to the book, rather than the e-book, since I am biased in that way, as well!

    • The panels in the best case are riven, quartered stock, so very little shrinkage across the width of the panel. Little expansion as well…worst thing that can happen to these panels is when their thickness shrinks, they can rattle…but it’s rare. Flatsawn panels are different, and need to be dry prior to assembly…

  4. Peter:
    We are concerned about your safety! Using a metal maul on metal wedges has mushroomed the wedges’ tops. Please grind the mushroomed heads away. Flying metal slivers can harm the body and are deadly to the eyes. We also use a metal maul but grind away any mushrooming frequently. A beetle could be used, but we find them bulky and hard to control. Did you have safety goggles on?

    Nathaniel Krause and Boneyard Jennie

  5. Peter: We have agreed upon the term “workable moisture content” to refer to that point when oak can be finally finished. However, I would like to instead propose “finish moisture content.” Green wood from the tree is workable, the difficulty is that the surface of the wood cannot be finished with the smooth plane until a certain lower moisture content is present. No moisture meter is necessary. In the case of flat stock run the smooth plane across the stuff’s ray plane surface. If the rays tear out, the stuff is still too moist. Though I own a moisture meter, I don’t have a clue as to the mc for finishing the stuff. There is no need to know. Just try smooth planing it.Turned stuff remains hairy until its surface dries to finish mc.
    Jennie
    ~

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