I've heard about tension in lumber before, but have never had it happen to
me prior to this instance. First the project, then the question. I made a
shadowbox frame from curly koa -- frame is 16x20, 2 inches deep and 1 inch
wide, I cut these pieces from a block that was about 40x9 and 2 inches
deep. after I cut the miters and glued everything up, noticed that when
laid it on a table, the frame was not flat -- had earlier cut two pieces off
the original board for my son in law, and when I mentioned this problem to
him, he remarked that he had the same problem with wood from that board..
Now my question -- the frame looks great and would like to salvage it -- is
there any way I can overcome this defect? When I lay the frame flat, one
corner is a bit over 3/8 of an inch off the table.
Did you resaw the wood from 2inches into two 1inch thicknesses, or did
you just rip 1 inch pieces off the original board? Did you find the
board curving or twisting as it came off the saw (this is pretty
obvious as it happens)? Did you allow the wood to acclimate to your
shop for at least a week, before and after you resawed/ripped it
(especially resawed)? It's also possible you introduced the twist when
gluing up the frame, depending on how you clamped it. Unfortunately, I
can't think of a way to salvage the frame short of cutting apart the
joints, jointing and planing the wood as needed, and regluing it,
slightly smaller of course. If you decide you have had it with that
wood, I'll pay shipping to my house! ;)
What you might try is to find some angle iron and see if you can slot the
frame on the back side and then screw the angle iron to the frame.
--
Roger Shoaf
About the time I had mastered getting the toothpaste back in the tube, then
they come up with this striped stuff.
"Herb Robinson" <[email protected]> wrote in message
news:F%vJd.2008$5t.1420@fed1read07...
> I've heard about tension in lumber before, but have never had it happen to
> me prior to this instance. First the project, then the question. I made
a
> shadowbox frame from curly koa -- frame is 16x20, 2 inches deep and 1 inch
> wide, I cut these pieces from a block that was about 40x9 and 2 inches
> deep. after I cut the miters and glued everything up, noticed that when
> laid it on a table, the frame was not flat -- had earlier cut two pieces
off
> the original board for my son in law, and when I mentioned this problem to
> him, he remarked that he had the same problem with wood from that board..
> Now my question -- the frame looks great and would like to salvage it --
is
> there any way I can overcome this defect? When I lay the frame flat, one
> corner is a bit over 3/8 of an inch off the table.
>
>
Herb Robinson wrote:
>
... wrt to reaction wood on 16x20 frame...
> Now my question -- the frame looks great and would like to salvage it -- is
> there any way I can overcome this defect? When I lay the frame flat, one
> corner is a bit over 3/8 of an inch off the table.
I know of no way other than restricting a piece of reaction wood from
moving by another piece strong enough to overcome it, unfortunately.
The only way you'll get around it w/ that particular piece of lumber
will be to cut pieces sufficiently oversize and let it move before final
milling.
Herb Robinson wrote:
>
> I ripped one inch pieces off the original board -- the original board had
> been in my shop for some time. I did not see anything unusual when ripping
> the board, but then I wasn't looking for any problem either. I worked the
> pieces that I ripped and glued them up within an hour or two. I doubt if
> the twist was induced when doing the glue up -- although I've read about
> this problem before, it's the first time it'd happened to me -- a real
> bummer! Thanks for the input.
...
That's unlikely to have been reaction wood that caused the problem
then...more likely uneven moisture movement. Allowing acclimization of
the pieces prior to final milling would probably have alleviated the
problem.
I ripped one inch pieces off the original board -- the original board had
been in my shop for some time. I did not see anything unusual when ripping
the board, but then I wasn't looking for any problem either. I worked the
pieces that I ripped and glued them up within an hour or two. I doubt if
the twist was induced when doing the glue up -- although I've read about
this problem before, it's the first time it'd happened to me -- a real
bummer! Thanks for the input.
<[email protected]> wrote in message
news:[email protected]...
> Did you resaw the wood from 2inches into two 1inch thicknesses, or did
> you just rip 1 inch pieces off the original board? Did you find the
> board curving or twisting as it came off the saw (this is pretty
> obvious as it happens)? Did you allow the wood to acclimate to your
> shop for at least a week, before and after you resawed/ripped it
> (especially resawed)? It's also possible you introduced the twist when
> gluing up the frame, depending on how you clamped it. Unfortunately, I
> can't think of a way to salvage the frame short of cutting apart the
> joints, jointing and planing the wood as needed, and regluing it,
> slightly smaller of course. If you decide you have had it with that
> wood, I'll pay shipping to my house! ;)
>
"Compression wood", at least in softwoods is one or two tight growth rings
that compensate for abnormal growing conditions, i.e., the tree grows on a
steep slope etc... again, in soft woods it is readily identified as an
extremely dark ring, and I suppose the same in other woods. When the
tension in the tree is released, there is still compressed wood that makes
for a tight ring. Sometimes, if you can identify the ring, you can rip on
either side and the board will eventually straighten out (usually your just
screwed tho..).
Sorry, sounds like a nice project...
Schroeder
"Herb Robinson" <[email protected]> wrote in message
news:F%vJd.2008$5t.1420@fed1read07...
> I've heard about tension in lumber before, but have never had it happen to
> me prior to this instance. First the project, then the question. I made
a
> shadowbox frame from curly koa -- frame is 16x20, 2 inches deep and 1 inch
> wide, I cut these pieces from a block that was about 40x9 and 2 inches
> deep. after I cut the miters and glued everything up, noticed that when
> laid it on a table, the frame was not flat -- had earlier cut two pieces
off
> the original board for my son in law, and when I mentioned this problem to
> him, he remarked that he had the same problem with wood from that board..
> Now my question -- the frame looks great and would like to salvage it --
is
> there any way I can overcome this defect? When I lay the frame flat, one
> corner is a bit over 3/8 of an inch off the table.
>
>