How to eliminate "bow" in length of stock?

[Louis Brandt]

Hello,

This is probably going to sound like a very dumb question, but I'm still somewhat of a newbie in woodworking, so please excuse it.
What’s the best tool and best method to use to plane down the middle section of a length of 1x12 stock? I have a piece that’s 5 foot long, and the middle area is slightly bowed up (just enough to keep the two ends from sitting flat down on another piece of 1x stock that I need to glue it to. I can’t turn it over and use the other side, and I can’t use another piece (for reasons that would be too lengthy to go into here). I need to remove (maybe 1/32, maybe slightly more) along the middle two or three feet of this material.
I’m afraid to glue it down without eliminating the bow, because I’m afraid that it might not hold or that the glue joint or the wood might break.
I don’t have a planer and don’t have room for one anyway. I don’t have a ROS either. I’ve tried sanding by hand with 60 grit, but I haven’t been able to remove enough to eliminate the "bow".
Is this just an issue of, "be patient and do lots of sanding" or is there a more efficient way?
Louis

[John Kain]

If you need to take out material in a specific area, then the easiest way is with a handplane......

Glue and alot of clamps can work wonders. Glue is stronger than wood (supposedly)

But it sounds like your board is warped. Perhaps a picture might help.......

[Alex Berkovsky]

Another newbie taking a crack at this... How about making and using a jointing jig similar to this one (http://www.newwoodworker.com/tsjointjig.html). Also, you can take a piece of MDF or any stock with a straight edge wide enough to carpet tape your stock to it (with your stock overhanging) and run through the table saw.

[Ben Grunow]

The same can be done with a thickness planer and you could even make a simple jig to joint with a router. I have seen posts on this here before. Sounds like a hand plane or belt sander job to me.

[Ian Barley]

Louis

Welcome to the wonderful world of wood (movement).

Can you tell us a bit more about your application? what sort of wood are you talking about and what is the purpose of the assembly you are making? Is it gonna go outside? Are we talking carpentry or fine woodworking?

The basic answer to your question is that you would ideally plane the timber flat on one side on a jointer and then use the flat side to run the whole thing through a planer to get the correct thickness. You don't appear to have these facilities so we need to know a bit more to be able to consider what you might "get away with".

The only thing I can tell you is that samdpaper is bery unlikely to figure strongly in any solution to this problem.

[Peter West]

How long is the board?

Do you have a router?

The cheapest and most effective way is if you could place the board on a flat surface - bow side up.

Place a peice of flat material just longer than your board (MDF or flat stock) either side of the board.
Suspend the router between the two peices of stock on some form of custom suspension plate wide enough to rest on the 2 peices of stock and spanning your board.
Then slide the suspended router along the length of the board to create a 'level' finish, (push the suspension plate rather than the router to give better contol and minimise downward flexing of the router, - adjusting the depth of cut until you are happy with the new surface).

I hope this makes sense.

Another alternative (if you can get hold of one - borrowed or purchased) is to use a router attached to a guide rail system to do a slightly more professional job in a similar way.

[Don Baer]

Sounds like a hand plane or belt sander job to me.


This is how I would do it.

[Cliff Rohrabacher]

Assumption: the bow is along the wide face not an edge.
Leave it out on a bench overnight, uncovered.
Leave the concave side down. When the tempratiure changes with the cooling of the evening the moisture will enter the exposed fase swelling it.
That may reverse the bow.

Failure to cover the lumber you have for the evening will raise the chance of bowed wood in the morning.

[Per Swenson]

Cliff is right.

Before you start routing and planing dampen the inside -) part of the bow.

Per

[Ernie Hobbs]

If you don't have access to a planer, If it were me, I'd use a hand plane. Lay the board bow side up and mark the high spots with a pen or pencil. Plane your marks away. Repeat as necessary.

Once you have one side flat, flip the board over and mark the high spots on the edges and plane until flat.

Regarding what type of hand plane, my favorite for this type of job is my old Bailey 4 1/2.

The easiest way to do this is find a neighbor or friend with a lunchbox planer somewhere. Then just run it through a few times, on each side until flat.

[Roger Meeker]

Hmmm, 1x12 with a 1/32" rise in the center...doesn't sound like a problem to me. I would forget about it and glue it to "whatever you're gluing it to." (provided the 1x12 is not the substrate for some veneer, which would also take the bow) If this is being glued to a thicker piece, then glue away!!

That being said, I can't praise enough the concept of clamping cauls to straighten a board when laminating it. Cauls are made from scrap stock, or two-by's that are perfectly straight on one edge (jointer). You just sandwich the boards you're joining/laminating between two cauls and apply the clamps.

Regardless, 1/32" over 5' of board is well within the range of wood movement.

[Mark Singer]

Material selection is sometimes the answer...use the bowed long piece to make shorter parts....aprons...for long stretchers and table tops...try touse the straighter stock.
The straightening techniques have been mentioned...If it is to be glued up as a panel....use a piec with the opposite bow and straigten them as you join them....or rip it in half and reverse...when you glue up

as mentioned it is not too much really and once it is part of the piece it will go away