I've spent about 5 hours milling up the piece of black walnut from
rough cut to final dimension for a project, a hope chest. The milling
came out pretty darn good, with the main panels (14" by 45" by 1')
turning out nice and flat, at least initially. After about 48 hours,
two of the four boards (by the way, they're all 2 piece glue ups) have
bowed, not horribly, but certainly enough to frustrate me as I was
planning to try hand cut dovetails along the 14" corner joints.
How might I have prevented this? (the boards were well aclimated to
the working environment, and, to the best on my knowledge, well dried
- though I don't have a moisture meter.) I'm wondering if I should
continue to even try to use the dovetail plan: I'd be trying to joint
two boards along a 14" joint where at least one board is bowed out
about 1/16th or perhaps slightly less, in the middle.
Any thoughts or suggestions appreciated.
As you produce a new exposed surface the board begins to shrink or swell as
the atmosphere dictates. Better to mill to the approximate thickness and
then let the board acclimate again. Then finish milling to the final
thickness. Also it is best to mill equally from both sides to help even out
any uneven moisture content on the sides of the board.
With only 1/16 bow you should be able to machine DT the panels as long as
you clamp the panel flat in the jig. Assembly will require a light
Hurry up and glue up! ... the longer your wait, the worse it may get.
1/16" over 14" is no big deal and can usually be "clamped out" in the glue
up of the dovetail joint. Using clamping cauls that fit over the pins or
tails is one way to insure this works.
If one side is not going to be seen you can always use a couple of well
jointed "battens", screwed down tightly on one side, to flatten the
offending board for the glue-up, then remove them later and fill the screw
But you really do need to waste no further time and "git r done".
The phrase "git r done" is from the comedian Larry the Cable guy.
It's his catch phrase.
Do a google search on Larry the Cable guy and you'll get a feel for
him. Big fella in a plaid flannel shirt with the sleaves cut off and
a cammie baseball cap. Hilarious. :-)
This isn't a problem for handcut dovetails... I've done them with boards
cupped worse than that and they straighten out well when you glue it up. One
way to deal with this is to clamp cawls to the boards to straighten them out
during layout--generally no need while cutting and chopping. Alternatively,
if you're careful about it you can do the layout as is and, assuming pins
first, slightly reposition the pin board as you lay out the tails.
Just noticed your ISP... come up to Saratoga Springs to the Northeastern
Woodworker's Associations annual Woodworker's Showcase the 24-25th of March.
I'll be there in the hand tool demo area by Toy Factory. It's planned that
I'll also be doing presentations on hand cut dovetails with Joe Kennedy. I'd
be happy to show you what I tried to describe.
Heh, I had something like this happen a few weeks back, only pretty badly:
ended up with some propeller blades, after dressing some boards for a bedside
table top and then leaving them on a varnished assembly table overnight.
I wet down the boards, put gauged stickers between them and clamped the mess
together - then I put them back on the workbench, but on edge, and with some
stickers underneath so the air could circulate freely. After 36 hours they were
straight enough for a fairly easy glue-up with only one or two exceptions that
just had ornery grain anyhow. Fortunately I had allowed quite a bit extra since
I resawed and then dressed them from some 6x1 r/s.
firstname dot lastname at gmail fullstop com
Not unusual for that width.
However, as one who has fought the wisdom of those who have gone
before me many times, I've finally given up. I don't glue up panels
with boards wider than four inches. I do reverse the end grain
direction in alternating boards, despite the fact that the board may
be a little better looking on the other side. I've given up fighting
the cross grain gluing gods, seems they win every time (I've a couple
of beautiful pieces of bedroom furniture that open a very nice crack
That said, you should be able to easily fit, clamp and glue a 1/16"
bow with dovetails. Might have to put a shim or strongback at the
clamp point to pull in the middle.
As Swingman said, go for it now, it ain't going to get any better in
I'm with you. For tops and lids I still try and get away with it on occasion
for my own personal pieces if the wood is just too pretty and figured to
chop up, and if I can batten one side when necessary. I figure as long as
I'm around and eating my own dog food, a lid or top can be re-done.
But, for those pieces destined for others, the prudent thing is veneering
for matched, "figured" grain on panels ... although I was slow coming to
that conclusion because there is something about a veneered piece that is
just too perfect and unreal for my taste.
Other responses provided some good advice. I'll try to answer how you can
prevent it in the future and maybe straighten what you have.
First, you may have released stresses in the wood that caused the bowing but
at only 1/16" - I'm betting these pieces were stacked without stickering
after you milled them or you left them laying on a flat surface where one
side was exposed to air. The side exposed to the air this time of the year
most likely dried out - very quickly. Take a sponge and lightly but evenly
moisten the side which is the inside curvature of the "U" shape on one of
the boards and let it rest overnight - face down and see if it doesn't go
flat. If it's due to stresses it won't and may in fact worsen but if it is
a moisture problem - or lack thereof on one side - you'll know soon enough.
To correct the problem, sticker the wood - cupped side face down and let it
rest for a day or two.
I'm not very fond of pulling wood into shape with clamps on a project where
it's just as easy to correct the problem first rather than trying to force
Learn to sticker all layers after milling to rough cut sizes and again after
milling to final sizes. That means the bottom pieces are not laying flat on
some surface - they are also stickered.
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