Is there any way to straighten bowed lumber? By bowed I mean the board
curves off to the left or right as you sight down its length. I have a
large amount of 5/4 by 4 inch cedar trim boards for the house I am building.
Most of these have become so badly bowed as to be unusable.
I thought about attaching a straight-edge and machining them straight on the
table saw, but I think they'd end up only being maybe two inches wide at the
Thanks for any help!
Not much can be done to straighten it other than muscling it into place
and holding with fasteners. If they're long enough, you could halve them
and then machine them straight - you'll have more width that way, but
shorter lengths to work with.
IIUC the board would sit more or less flat on the floor. If that is
the case the bending is called 'crook'. Bow is in the other plane
so that the board would rock or be arched when on the floor.
Yes, but that is probably what you'll have to do.
If you cut them into short lengths then joint them you'll get more
board feet of usable lumber--but all short pieces. Should be OK
if you're building bird houses or mailboxes or some such.
You can also google the thread on cooking salmon on cedar planks...
OK, crook. Funny I never knew that. Must be where crooked comes from :-)
What about placing two board side-by-side on pipe clamps with the crook in
opposite directions and gluing with polyurethane glue? Will it hold?
Not really a good idea Tony. You have no idea - and no control over which
of the two is exerting more force in the curve, so rather quickly you could
find yourself with a crooked laminate. As well, while glued joints are
strong you really don't want to introduce stresses like that into a glue up.
You'd be far better off to rip a straight edge on each of the two pieces and
glue that edge up. After that you could rip the whole thing again to true
up the two outer edges.
I've never actually tried this, so maybe some of the other guys should
comment on whether or not it makes sense.
What about ripping right down the middle, then edge-gluing the curved
surfaces together? It might be a bit of fiddly work getting the two
curves to line up, but it seems like a pair of templates and a router
should work for that.
That way you'd end up with a full-length board--although the grain would
be a bit odd.
What might work would be to use one half for the template, have them
spaced just a bit closer together than the size of pattern bit you
have, then raise one up so the bearing runs against it and the bit cuts
the lower one to match.
If this is exterior trim and the lengths are long I'd be inclined to nail it
in place while bending it into place... Cedar is relatively soft and easy to
straighten out while nailing up... I'm assuming of course you aren't talking
about wood so crocked that the ends touch!
I'd try to make a jig to hold the pieces firmly that allows the pieces
to be straiten by applying counter pressure to the bend area, keep a
sprinkler going on the wood, after several hours you'd be able to
determine if it actually works.????
I did that once; wet the board and recurved it for a couple days to let it
dry. It took out about half the curve, but a few days later it was back
where it started.
It turned out to be a bad news/good news joke.
The bad news it that it didn't go back to it's original shape until after I
The good news is that the curve turned out to be a nice design note; now I
claim to have done it on purpose.
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