question about a bowed piece of lumber

  • Advertise with us

« back to Wood & Lumber forum

Forum topic by DTrak posted 12-23-2015 11:50 AM 374 views 0 times favorited 4 replies Add to Favorites Watch
View DTrak's profile


39 posts in 521 days

12-23-2015 11:50 AM

Newbie question..
I bought this Walnut slab (see photo) and had it sliced in thirds at the lumber yard because I plan to add other strips of wood in the center to make it wide enough for a dining table. Notice how one of them is bowed and therefore wont cleanly line up if I were to glue other strips of wood to it (it’s flush at the ends, just not the middle). I think it is the live edge strip on the right because the middle one measures equally everywhere.

How did that happen? It must have been straight when they cut it, so is that just the result of it sitting in my basement and being exposed to temperature changes? Why only that strip and not the other two?

What do I do now? Is the only solution to run the bowed piece through a joiner? I don’t own a joiner and havent found a place around here who can do that for me. Is there another solution? Would some sort of table saw (I have that) jig work here?


4 replies so far

View kaerlighedsbamsen's profile


1170 posts in 1138 days

#1 posted 12-23-2015 12:29 PM

Could be a number of reasons but the large knot in the bowed board probably adds a lot tention and is part of the cause. Perhaps read up on tree anatomy and such if you are at the computer anyway. A good place to start is here.

If the board is thorough dry just:
a: Plane it straight with a jointer plane
b: Clamp it to a perfectly straight board and run throug table saw
c: Clamp a perfectly straight board to it and run a router along it
..and so on
Remember to joint all three boards

Good luck. Please tell us how it went!

-- "Do or Do not. There is no try." - Yoda

View rwe2156's profile


2128 posts in 905 days

#2 posted 12-23-2015 12:36 PM

Internal stresses around the knot were released when it was cut.

You can get a decently straight edge with a straight edge guide + either a circ saw or TS (better).
Its difficult to get a glue ready cut right off a saw. You can try a “glue line rip” blade.
For me, I would follow up with a jointer plane.

The problem is there is so much stress around knots like this the wood will often just keep bowing. All you can do it try. You may have to joint it several times.

You may be forced to eliminate that piece of wood.
Lesson learned: don’t rip a board like this in half.

-- Everything is a prototype thats why its one of a kind!!

View Tennessee's profile


2410 posts in 1939 days

#3 posted 12-23-2015 12:54 PM

I agree that the large knot is starting to relieve itself. If you can joint it through either a jointer, some kind of saw cut, or even using a jointer hand plane, it may try to keep relieving itself. If you do get it clamped up before that happens, it may bow the whole board a bit when it relieves again. Just don’t know. I’d make sure it does not bow again before gluing after you do get a straight edge.

-- Paul, Tennessee,

View DTrak's profile


39 posts in 521 days

#4 posted 12-23-2015 04:41 PM

I think I know what I need to do. thanks for all your advice.

Have your say...

You must be signed in to reply.

DISCLAIMER: Any posts on LJ are posted by individuals acting in their own right and do not necessarily reflect the views of LJ. LJ will not be held liable for the actions of any user.

Latest Projects | Latest Blog Entries | Latest Forum Topics