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
JGS asks:
>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?
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
JGS <[email protected]> wrote in
news:[email protected]:
> 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
>
>
>
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 <sp?> 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
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.
"Charlie Self" <[email protected]> wrote in message
news:[email protected]...
> JGS asks:
>
> >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?
>
> 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
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
David Babcock states:
>As for the difference
>in white v. red, red tends to be tighter, slower growing trees.
>
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
Charlie Self wrote:
> 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.
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.
--
Michael McIntyre ---- Silvan <[email protected]>
Linux fanatic, and certified Geek; registered Linux user #243621
http://www.geocities.com/Paris/Rue/5407/
On Sun, 16 Nov 2003 06:04:27 -0500, JGS <[email protected]>
wrote:
> 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
>
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.
On Sun, 16 Nov 2003 06:04:27 -0500, JGS <[email protected]>
wrote:
> 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
>
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
http://users.snip.net/~tjwatson
On 16-Nov-2003, Tom Watson <[email protected]> wrote:
> > 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
> >
>
> 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.
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
<http://www.leevalley.com/wood/page.asp?page=31161&category=1,45866,45867&abspage=1&ccurrency=1&SID=>
Mike