Em

"Eigenvector"

02/08/2007 5:35 PM

squaring bowed wood

Let's say you have a long board that has a bow to it - nothing huge but
maybe 1" deflection over 8 feet on a 6" board. How would you remove that
bow? I'm thinking about it and wonder, because you don't have a straight
edge to use as as reference point, removing the bow with a bandsaw or
tablesaw seems terribly wasteful, but bending a 6" board doesn't seem
possible.


This topic has 12 replies

Em

"Eigenvector"

in reply to "Eigenvector" on 02/08/2007 5:35 PM

04/08/2007 12:31 PM


"George" <[email protected]> wrote in message
news:[email protected]...
>
> "Eigenvector" <[email protected]> wrote in message
> news:[email protected]...
>> Yes, crook is what I meant - thank you. I can see how what you do would
>> work. Attaching a known quantity to the board for reference marks so
>> that you can run it through the bandsaw or tablesaw with minimal waste.
>>
>
> We pretty much knew from your description what you meant. Basics, if
> you're interested in precise terminology, are bow, cup, twist and crook.
> Good stuff at
> http://www.fpl.fs.fed.us/documnts/fplgtr/fplgtr113/fplgtr113.htm if you're
> curious as to the nature of wood and why it does what it does.
>
Oh man, I'll be reading that for about a hundred years. Print it out and
stick it in the shop.

Thanks again.

> With a tablesaw setup on a large board you're actually creating a larger,
> more unwieldy board by jigging. Lot easier and safer to snap the line and
> bandsaw for reference.


dd

"dadiOH"

in reply to "Eigenvector" on 02/08/2007 5:35 PM

03/08/2007 9:41 AM

Eigenvector wrote:
> Let's say you have a long board that has a bow to it - nothing huge
> but maybe 1" deflection over 8 feet on a 6" board. How would you
> remove that bow? I'm thinking about it and wonder, because you
> don't have a straight edge to use as as reference point, removing
> the bow with a bandsaw or tablesaw seems terribly wasteful, but
> bending a 6" board doesn't seem possible.

Bending out a 1" deflection over eight feet on a 6" board is nothing.
You think the planks on a boat grew bowed? The necessary bending on
those is/can be measured in feet for a middle size boat. Now, if you
meant crooked rather than bowed, that's a different thing.

--

dadiOH
____________________________

dadiOH's dandies v3.06...
...a help file of info about MP3s, recording from
LP/cassette and tips & tricks on this and that.
Get it at http://mysite.verizon.net/xico


Gg

"George"

in reply to "Eigenvector" on 02/08/2007 5:35 PM

04/08/2007 8:33 AM


"Eigenvector" <[email protected]> wrote in message
news:[email protected]...
> Yes, crook is what I meant - thank you. I can see how what you do would
> work. Attaching a known quantity to the board for reference marks so that
> you can run it through the bandsaw or tablesaw with minimal waste.
>

We pretty much knew from your description what you meant. Basics, if you're
interested in precise terminology, are bow, cup, twist and crook. Good
stuff at http://www.fpl.fs.fed.us/documnts/fplgtr/fplgtr113/fplgtr113.htm
if you're curious as to the nature of wood and why it does what it does.

With a tablesaw setup on a large board you're actually creating a larger,
more unwieldy board by jigging. Lot easier and safer to snap the line and
bandsaw for reference.

Em

"Eigenvector"

in reply to "Eigenvector" on 02/08/2007 5:35 PM

03/08/2007 4:59 PM


"Larry W" <[email protected]> wrote in message
news:[email protected]...
> In article <[email protected]>,
> Eigenvector <[email protected]> wrote:
>>Let's say you have a long board that has a bow to it - nothing huge but
>>maybe 1" deflection over 8 feet on a 6" board. How would you remove that
>>bow? I'm thinking about it and wonder, because you don't have a straight
>>edge to use as as reference point, removing the bow with a bandsaw or
>>tablesaw seems terribly wasteful, but bending a 6" board doesn't seem
>>possible.
>>
>>
>
> I think you mean "crook" rather than "bow", i.e. the curve is in the same
> plane as the widest dimension of the board. What I do is temporarily
> attach another board with a good straight edge to the crooked board,
> so that the straight board can ride against the table saw fence. (A length
> of plywood with the factory edge makes a good straight edge for this use)
> Position the 2 boards and the saw fence so that the crooked edge can be
> ripped off. Then remove the straight edge, flip the crooked board over
> so the just-ripped edge can ride the fence, and rip off the other crooked
> edge.
>
> I don't jave a jointer, but even if I did I believe I would still use
> this method for an 8 ft board that had 1" of crook to it.
>
>
> --

Yes, crook is what I meant - thank you. I can see how what you do would
work. Attaching a known quantity to the board for reference marks so that
you can run it through the bandsaw or tablesaw with minimal waste.

LB

Larry Blanchard

in reply to "Eigenvector" on 02/08/2007 5:35 PM

04/08/2007 9:29 AM

In article <[email protected]>,
[email protected] says...
>
> "Eigenvector" <[email protected]> wrote in message
> news:[email protected]...
> > Yes, crook is what I meant - thank you. I can see how what you do would
> > work. Attaching a known quantity to the board for reference marks so that
> > you can run it through the bandsaw or tablesaw with minimal waste.
> >
>
> With a tablesaw setup on a large board you're actually creating a larger,
> more unwieldy board by jigging. Lot easier and safer to snap the line and
> bandsaw for reference.
>

If I didn't need the whole 6' in one piece I'd cut the board into two
and thus minimize the loss due to the bow.

LH

"Lowell Holmes"

in reply to "Eigenvector" on 02/08/2007 5:35 PM

03/08/2007 12:47 AM


"Eigenvector" <[email protected]> wrote in message
news:[email protected]...
> Let's say you have a long board that has a bow to it - nothing huge but
> maybe 1" deflection over 8 feet on a 6" board. How would you remove that
> bow? I'm thinking about it and wonder, because you don't have a straight
> edge to use as as reference point, removing the bow with a bandsaw or
> tablesaw seems terribly wasteful, but bending a 6" board doesn't seem
> possible.
>
I would probably make two 4' boards out of it and remove the bow that's
left with a handplane or my jointer. That's why I buy rough wood. The extra
thickness will allow you to straighten the board.

Gg

"George"

in reply to "Eigenvector" on 02/08/2007 5:35 PM

03/08/2007 9:49 AM


"Eigenvector" <[email protected]> wrote in message
news:[email protected]...
>>> Let's say you have a long board that has a bow to it - nothing huge but
>>> maybe 1" deflection over 8 feet on a 6" board. How would you remove
>>> that bow? I'm thinking about it and wonder, because you don't have a
>>> straight edge to use as as reference point, removing the bow with a
>>> bandsaw or tablesaw seems terribly wasteful, but bending a 6" board
>>> doesn't seem possible.

> Well I guess that answers it. For small bows, smooth them out, for big
> bows, smaller boards.
>

Well, there's always the chalk line and bandsaw method for edges. Superior
to any tablesaw jig I've ever used at safely getting things in the ballpark.

The hand plane guy takes the convex part down to a snapped line, the jointer
guy takes the concave part, runs two ends then the entire. Or, if he's one
who thinks a long-bed jointer is magic, he might try to hack the whole thing
at once.

If you're talking the face of the board, which I didn't read, but others
did, there are three letters that cover getting a straight board - SOL. Set
it aside for short pieces. Yet another reason for sighting your lumber
prior to preparation. It keeps you from hacking up something straight for
small stuff and trying to use something bowed at full length.

Em

"Eigenvector"

in reply to "Eigenvector" on 02/08/2007 5:35 PM

02/08/2007 6:48 PM


"dpb" <[email protected]> wrote in message news:[email protected]...
> Eigenvector wrote:
>> Let's say you have a long board that has a bow to it - nothing huge but
>> maybe 1" deflection over 8 feet on a 6" board. How would you remove that
>> bow? I'm thinking about it and wonder, because you don't have a straight
>> edge to use as as reference point, removing the bow with a bandsaw or
>> tablesaw seems terribly wasteful, but bending a 6" board doesn't seem
>> possible.
>
> That's why you have the longbed jointer... :)
>
> It's either straighten the board if you need the full length or use
> shorter sections of it so the waste isn't as much. That's woodworking...
>
> If, otoh, it was a 1x fascia board or something similar, and construction,
> not "woodworking", it would be quite possible in many circumstances to
> nail it in place on one end and spring it into alignment as one worked
> one's way along the length. Much depends on the circumstances...
>
> --

Well I guess that answers it. For small bows, smooth them out, for big
bows, smaller boards.

dn

dpb

in reply to "Eigenvector" on 02/08/2007 5:35 PM

02/08/2007 8:10 PM

Eigenvector wrote:
> Let's say you have a long board that has a bow to it - nothing huge but
> maybe 1" deflection over 8 feet on a 6" board. How would you remove that
> bow? I'm thinking about it and wonder, because you don't have a straight
> edge to use as as reference point, removing the bow with a bandsaw or
> tablesaw seems terribly wasteful, but bending a 6" board doesn't seem
> possible.

That's why you have the longbed jointer... :)

It's either straighten the board if you need the full length or use
shorter sections of it so the waste isn't as much. That's woodworking...

If, otoh, it was a 1x fascia board or something similar, and
construction, not "woodworking", it would be quite possible in many
circumstances to nail it in place on one end and spring it into
alignment as one worked one's way along the length. Much depends on the
circumstances...

--

lL

[email protected] (Larry W)

in reply to "Eigenvector" on 02/08/2007 5:35 PM

03/08/2007 5:46 PM

In article <[email protected]>,
Eigenvector <[email protected]> wrote:
>Let's say you have a long board that has a bow to it - nothing huge but
>maybe 1" deflection over 8 feet on a 6" board. How would you remove that
>bow? I'm thinking about it and wonder, because you don't have a straight
>edge to use as as reference point, removing the bow with a bandsaw or
>tablesaw seems terribly wasteful, but bending a 6" board doesn't seem
>possible.
>
>

I think you mean "crook" rather than "bow", i.e. the curve is in the same
plane as the widest dimension of the board. What I do is temporarily
attach another board with a good straight edge to the crooked board,
so that the straight board can ride against the table saw fence. (A length
of plywood with the factory edge makes a good straight edge for this use)
Position the 2 boards and the saw fence so that the crooked edge can be
ripped off. Then remove the straight edge, flip the crooked board over
so the just-ripped edge can ride the fence, and rip off the other crooked
edge.

I don't jave a jointer, but even if I did I believe I would still use
this method for an 8 ft board that had 1" of crook to it.


--
Make it as simple as possible, but no simpler.

Larry Wasserman - Baltimore Maryland - lwasserm(a)sdf. lonestar. org

dn

dpb

in reply to "Eigenvector" on 02/08/2007 5:35 PM

04/08/2007 12:13 PM

Larry Blanchard wrote:
> In article <[email protected]>,
> [email protected] says...
>> "Eigenvector" <[email protected]> wrote in message
>> news:[email protected]...
>>> Yes, crook is what I meant - thank you. I can see how what you do would
>>> work. Attaching a known quantity to the board for reference marks so that
>>> you can run it through the bandsaw or tablesaw with minimal waste.
>>>
>> With a tablesaw setup on a large board you're actually creating a larger,
>> more unwieldy board by jigging. Lot easier and safer to snap the line and
>> bandsaw for reference.
>>
>
> If I didn't need the whole 6' in one piece I'd cut the board into two
> and thus minimize the loss due to the bow.

And if I did, I'd probably select another board... :)

--

Em

"Eigenvector"

in reply to "Eigenvector" on 02/08/2007 5:35 PM

02/08/2007 6:49 PM


"Lowell Holmes" <[email protected]> wrote in message
news:UWusi.1519$BQ.919@trnddc03...
>
> "Eigenvector" <[email protected]> wrote in message
> news:[email protected]...
>> Let's say you have a long board that has a bow to it - nothing huge but
>> maybe 1" deflection over 8 feet on a 6" board. How would you remove that
>> bow? I'm thinking about it and wonder, because you don't have a straight
>> edge to use as as reference point, removing the bow with a bandsaw or
>> tablesaw seems terribly wasteful, but bending a 6" board doesn't seem
>> possible.
>>
> I would probably make two 4' boards out of it and remove the bow that's
> left with a handplane or my jointer. That's why I buy rough wood. The
> extra thickness will allow you to straighten the board.
>
Okay, that would explain why rough is not sold in specific thicknesses - it
gives you some room to play with.


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