getting boards flat

[Gregg Feldstone]

I only have a 6" jointer and need to straighten some 2x10's which are 5 ft. long, which I'm using to rebuild a benchtop. They are moderately bowed lengthwise and I have gotten them a little better with my planer but far from perfect.
I once took the guard off the jointer and did one half than the other with mixed results...plus this is dangerous. I am not great at hand planing yet.
I will be placing a 3/4" top of oak ply on top of these pine boards, which will hopefully keep them from bowing, plus the entire top will be bolted onto to the metal tool cabinet I am making it for.

Any suggestions??

[glenn bradley]

Is something going on top of the oak ply? The veneer is pretty thin. To your question; if the boards are not too bad you can urge them into position and glue and screw the ply to keep them there. This would not be your best choice. Since the boards will be covered anyway, rip them down the middle and joint as usual.

[Gregg Feldstone]

The top consists of two 10" wide boards which I plan to joint together.
You are saying to simply rip them into 4 (or more) boards so they are narrow enough to face joint? I wish I had thought of this because they are cut exactly to size already and I would lose at least 1/4". Looks like a might have to start over with another 2x12x10....$$

[glenn bradley]

Ouch. I hate it when I do something like that (cut to size and then realize I have a cut left to do). It is so easy after the fact to say 'what was I thinking'. On the upside your bench will be how you want it for many years to come and you'll have some spare 2 by material around for something in the future

[Eric Wong]

Do you have a planer? If you have time to build a torsion box jig from plywood, you can then use hot melt glue to tack the 2x10 to the jig and run it through the planer. Once one side is flat, you can remove the board from the jig, flip it over, and plane the other side.

[Dan Owen]

Rip them, joint them, plane them and then glue them up. The life of a 6 inch jointer guy.

[Randall Frey]

Gregg, There are a few ways to get this done. Take the boards to a shop that has a jointer that can flatten one side, then run them through your planner If you want to do it yourself you can make a planner sled. The work piece sits on top of the sled that has adjustment screws or wedges that will support the work piece as it is fed through the planner. Once the piece is flat on one side plane the other side and your done. I just recieved a free copy of Woodsmith in the mail and there is one in there. I built a real nice one featured in Fine Woodworking a little over a year ago. I had some beautiful Sapele wood that would have been a sin to rip to fit my jointer and my pride wouldn't let me take it to a shop.

[Tom Cowie]

Another vote for the planer sled idea. I also have a 6" jointer that limits the board width that I can joint. The sled has bailed me out many times. I clamp the board to the sled , once a level plane has been found, with smaller wooden blocks,wedges and some screws. I have never had a board move in the planer, and I just take the amount I need off the board.

This may seem more time consuming ,and I still rip, joint and glue many times but if it's an important board it will give you another option.

If you decide to build this jig, build it large enough to handle most of the lengths that you work with. I sometimes let a long board hang over the end and it does fine

Hope this helps

Tom

ps. I'm just not ready to get rid of that little jointer yet it has done alot of work for me.:p :p

[Grant Wilkinson]

Take the guard off your jointer and set the infeed height to 1/8". Run the board through only once. Attach a piece of 1/2" or 3/4" mdf to the jointed face of the board using double-sided tape. The mdf should be the same width as the jointed face = 6". Now run that through your planer with the mdf riding on the planer table. If the 1/8" cut you took on the jointer left you with a flat face, the mdf in perfectly flat too. The planer will make the 10" face flat and parallel. Then, you remove the mdf, flip the board over and plane until the 1/8" ridge is gone.

I've done this with lots of 8" oak and it works perfectly.

Grant
Ottawa ON

[jim gossage]

i really like grant's idea. can't wait to try it!

[Grant Wilkinson]

Tks, Jim.

I should clarify that I only said to set your jointer to 1/8" because you only get one shot at it. If the board is good enough to get a flat surface taking less than 1/8", go for it.

Grant

[Eric Wong]

hey Grant, cool idea! I'm going to try that one next time.

As far as the Planer sled goes, I've seen many with all sorts of wedges and stuff. But hot melt glue works great and is a lot simpler--you can fill gaps with it and tack the board down at the same time.

[Mark Carlson]

Tks, Jim.

I should clarify that I only said to set your jointer to 1/8" because you only get one shot at it. If the board is good enough to get a flat surface taking less than 1/8", go for it.

Grant

Grant,

I dont understand why you only get one shot at it? I've used this technique in the past and do multiple passes at 1/16 of an inch or less.

~mark

[Rod Sheridan]

So, after the "take the guard off the jointer" idea has been around for a few days will we see a new "How do I retrieve my fingers from the cyclone and dial 911" thread?

I can't believe we're telling someone to remove the guard from a piece of machinery to save time.

Regards, Rod.

[Matt Day]

So, after the "take the guard off the jointer" idea has been around for a few days will we see a new "How do I retrieve my fingers from the cyclone and dial 911" thread?

I can't believe we're telling someone to remove the guard from a piece of machinery to save time.

Regards, Rod.

I'm not by any means saying it's safe to remove the guard, but the entire width of the cutter head would be covered with wood during the cut so I don't think it's *that* bad.

[Alex Berkovsky]

I am also building a sled featured in the FWW magazine. I recently used a different method though... you can cut 2 5' long 1 1/2" wide strips of plywood and either screw or glue them to the sides of the board to elevate the board. I had a 1/2" thick narrow piece of ply (narrower than the board being planed) which I placed on my workbench. I then put the board on top of the ply and screwed the strips into the board. If for some reason you can't have the holes on the side of the board, use hot melt glue instead. You then run the board through the planer to flatten one side. Once flat, you remove the strips and run the other side through the planer.

[Roger Wilson]

If money is an issue go ahead and rip the boards so you can flatten them on the jointer. I would think you must have an old 2x4 around someplace, new ones only cost a few bucks. Rip off whatever you need to get your newly ripped 2x10's back to the width you want. Glue the narrow strip into the center for symmetry's sake and you are up and running.

Money not being a problem, I'd make a planer sled. It really works. Use very light cuts and you can flatten a board quite nicely. The FWW one uses shims with sandpaper on them to handle twisted boards. Hot glue and shims would be easier to put together though.

[Grant Wilkinson]

Mark
I said one pass only because if you try a second or more pass, you must make sure you support the wood on the thickest edge or you will simply continue to bevel the board thinner and thinner. You're right, though, it can be done.

Rod
I agree that taking the guard off isn't optimal, but the entire cutter and beyond is covered by the board. The only way to catch fingers would be to overlap the end of the board with your fingers, and you can do that with the guard in place. With respect, I don't agree with your point.

Grant
Ottawa ON

[Rod Sheridan]

The guard is off for the entire jointing process, not just the time when the workpiece is on the jointer, so to say it's covered by the workpiece, simply isn't correct.

Regards, Rod.

[Mark Carlson]

When Fine Woodworking showed a similar technique the author recommended installing a shop built guard during the operation. Basically two boards that formed an L shape, clamped to the fence over the blade.

Grant,
On my powermatic 54A I dont get the behaviour you describe. Nothing supports the rough part of the board so I dont get a bevel effect. If I took off too much I would eventually hit the rabbit ledge. I havn't done it recently so I'll have to try it again to see if I'm missing something. Thanks for your reply.

~mark

[Gregg Feldstone]

I appreciate all the responses. Is it possible the board could tilt in the planer because only 60% of it is sitting flat on the bed? (refering to the face jointing with guard removed technique).

[Grant Wilkinson]

Gregg
I've not had that happen yet. In your case, more than half the width is supported, plus the 60% that is supported weighs a lot more than the other part, since it includes the mass of the mdf. Take light cuts and I don't think you'll have any problems.

Grant
Ottawa ON

[John Hain]

Build a planer sled, save your fingers. Accidents are called such because no one thinks they'll happen.

[James E Clark]

Put 2 rails along each side of the material to be flattened,Now run 2 more peices of "1 x 3"x16" hardwood material from side to side attaching them to the long runners with screws or nails Be sure to positiob the hardwood runners so your routers baseplate will be able to move from side to side without falling through.now set your router on top of the hardwood runners,set the bit so it takes off only a couple 32nds to a pass and wa la flat material. Granted this way takes a while but it beats the heck out of a warped bench top. I use this method whenever I have a panel that won't fit my planer. It takes a little sanding but again it beats the heck out of hills and valleys.
Sincerely,
Jim C