I forgot stability

splitting radial panel stock with a froe
splitting radial panel stock with a froe

In my last post, the one about riven oak & how great it is, https://pfollansbee.wordpress.com/2009/10/18/theres-oak-then-theres-riven-oak/

I forgot one of the most important aspects of riven, radial oak – the stability! It shrinks very little across its face, thereby allowing the joiner to work the wood while it is green, and therefore easier to cut/plane/carve/mortise, etc.

You do need to select the log with care. To be able to rive parts efficiently, you need a dead-straight log. This then will behave best when it loses its moisture, less tension, thus less distortion. Mostly imperceptable.

One reader asked about the lengths that riven stock is best for; and in my work the largest challenge length-wise is making an oak chest lid of three or four radially-split boards edge-glued together. I have one underway now, the boards are about 58″ long, 1″+ thick, and seven or so inches wide. It takes a really good log to get those riven without much wind, or twist in the faces of the boards. So usually these are riven oversize, and hewn to rectify before planing. Otherwise most everything is four feet or less for joined furniture; in many cases quite short. For instance, muntins in a chest are about 14″-17″ long…very easy to get from a log.

I find a riving brake essential for careful riving of anything more than two feet long…here’s one I use a lot. A large wooden tripod, with cross-bars fastened to its front legs. Jam the stock in this crotch, and that allows you to exert pressure on the split to help direct it if it is going astray.

riving brake
riving brake

I learned this brake from my friend Daniel O’Hagan, who is pictured in Scott Landis’ The Workbench Book using one of these contraptions. The thing I like about it is that the stock is held parallel to the ground, so you can apply pressure easily. Other brakes I’ve seen leave the workpiece tilted up to the sky, and it’s harder to manage them that way. Says me.

In the shots belowe, I was riving the sapwood off some stuff for a pair of stilts I had to make last week. My friend Marie came by & I asked her to get some shots. Thanks, Marie.

riving brake
riving brake
riving brake
riving brake
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5 thoughts on “I forgot stability

  1. Thanks so much for showing us how you rive longer boards. I’ve done some riving of firewood, as much to justify my “need” for a froe as anything else (grin). I followed the techniques John Alexander shows in his How to Make a Chair video but I’ve never seen longer work being done. Thanks for illustrating it.

    Cheers — Larry

  2. Looky here! Real boards riven from a tree! Incredibly enough, in 17th Century joinery sawing is rarely done in the direction of the long fibers. If you haven’t done so, I suggest try riving a short piece of straight grain oak. No froe? Try riving a small diameter piece with an axe pounded by a wooden club. Whenever possible rive stock in half lest the split run out. Interested? See Riving Wood For 17th Century Joint Furniture, http://www.greenwoodworking.com.

    Jennie
    ~

  3. Peter,

    Very cool stuff but did it really take so long to rive that stuff that you went from jeans in picture 2 to shorts in picture 3?

    Guess I’ll head oout to the shop and make me one of those horizontal brakes. Should make like easier. Thanks for sharing.

    Chuck

  4. LOL @ I forgot stability.

    Yes, it’s really quite amazing, that green, riven wood works well and is so stable, even hundreds of years later it seems unaffected by time, moisture transfer, etc.

    I wonder why? Is it because joined furniture is made up of many small parts?

  5. Chuck: those pictures span some time…but as it turns out, here in southeastern Massachusetts last week, I scraped ice off the car one day, and it was 71 degrees a couple days later. So shorts & sweaters are both in rotation around here.
    Do make one of those brakes, they are really quite helpful for longer stuff.

    James – the stability stems from the radial orientation. Wood shrinks less in that direction than tangential to the growth rings. It is further enhanced by the straight-grained nature of a log good enough to rive…

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