Bending Quarter Sawn Oak

We have made several attempts to bend 1/2" strips of quarter sawn white oak into a circle about 30" in diameter. We are experiencing a lot of splitting at the edges. The wood has been air dried for about 8 months. We steam if for about an hour, use a compression strap and a form. Using this same set up we successfully bent kiln dried red oak last spring. Does Q sawing effect bendability? Any other ideas? Thanks, JG

Reply to
JGS
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JGS asks:

I've never tried bending QS oak, but see if you can get hold of some green QS and try that. I'd guess--my science isn't good enough to be sure--that the QS does affect the bendability.

Takes forever and a day to get ready (you have to dry it afterwards), but usually green wood bends more easily.

Good luck.

Charlie Self "I hope our wisdom will grow with our power, and teach us, that the less we use our power the greater it will be." Thomas Jefferson

Reply to
Charlie Self

If you take a look at any qs wood the cut tends to expose the grain (growth rings) hence the splitting, where straight cut wood blends the grain. The splitting your getting is the separation of the rings. As for the difference in white v. red, red tends to be tighter, slower growing trees.

Reply to
David Babcock

David Babcock states:

I dunno. I think that varies. I've pin oaks in my yard down in Virginia that are growing faster than the white pines at the other end. Those are classed, I think, as red oaks, though the actual wood is better for firewood than woodworking. Great lawn trees, though: they eventually kill the grass under and have a drooping habit that saves mowing a very large patch.

Charlie Self "I hope our wisdom will grow with our power, and teach us, that the less we use our power the greater it will be." Thomas Jefferson

Reply to
Charlie Self

JGS wrote in news: snipped-for-privacy@sympatico.ca:

A few things that I learned from a Windsor Chairmaker:

  1. Each oak tree bends differently. Some won't bend.
  2. It does not matter if it is quarter sawn or not.
  3. Your bend success rate goes up if your piece is first cut so that it follows the years of annular growth. (riven wood is better than sawn wood.)

When wood splits at the edges, the grain is running off the piece of wood. This means that the grain has no support and is resisting the bend.

It is also possible that there is too much moisture in the wood. Water does not compress well (which is partly what you are doing when you bend wood). I was taught that green wood is actually worse to bend than drier wood. Steam plasticizes the wood but does not necessarily increase it's moisture content by any great amount because of the short time frame. If the wood has too much water in it, the heat will cause it to expand inside and create a higher possibility of splitting.

Tony

Reply to
CodeW

I don't think the QS oak effects the bendability. Not sure about your particular application, but kerf the unseen side if there is one. Or, use a thinner piece. You could bend several thin pieces, let them dry and glue them up (that's how they make strong banisters). Some woods steam bend better than others. Ash bends well. There are a few tricks to steam bending. Obviously, kiln-dried wood will split more readily than air-dried or green.

Reply to
Phisherman

QS Air-Dried White Oak should bend beautifully. Air drying preserves the structure of the lignin, rather than altering it in the way kiln drying does. The fact that it is QS should let it bend evenly without deforming across the face and will keep you from worrying about the wood lifting (delaminating) on the late wood/early wood intersections, as can sometimes happen with bent flatsawn stock.

Two things that you might want to consider:

Make sure the pieces are straight-grained, without a lot of grain runout at the edges.

Try chamfering the edges slightly. This has helped me in the past when splitting out on the edges was happening.

Regards, Tom Thomas J. Watson-Cabinetmaker Gulph Mills, Pennsylvania

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Reply to
Tom Watson

My kind of guy. Screw grass! :)

Unfortunately, it's not working in either of the yards I take care of. All those Arbor Day trees I planted when I was a kid are quite tall now, but not full enough to kill the #$@#%@ grass in that horrible slalom I crafted for myself. Here at home, all my trees are babies, and my kids will probably be grown and gone before they save me any mowing.

Reply to
Silvan

Good advice. White oak is one of the best woods for bending. Air dried is ideal.

BTW - one hour for 1/2 inch is too long. It should be about half hour (one hour per inch). You want to heat it, not cook it. Make sure you're getting a good temperature - use an oven thermometer and check that it's as close to boiling temp as possible - 98-100C (208-212F) should be possible with a good steam box.

Download the Veritas steam-bending booklet from Lee Valley

Mike

Reply to
Michael Daly

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