Jointer technique

[Michael O'Sullivan]

What is the best way to face joint a board where there is a high area toward the middle of the board?

My issue is that my regular technigue -- pressure on the outfeed side, but not the infeed side -- can accentuate the problem, because the high point acts as a fulcrum. I end up taking a lot off the front end of the board, nothing off the back, and the high area stays high.

[Larry Edgerton]

I always joint out the belly of the curve, starting with the middle and working to the ends with light passes.

If you do it the other way, belly up, you need too long a jointer on really long stock because the tail coming in lifts the middle.

[Lee Schierer]

I would put the board on my TS and rip off the belly and then run it across the jointer. If the opposite side isn't flat, I have a 1" square aluminum tube that is 6' long with a small angle attached to one side near the end of the tube, that I put against my fence and place wooden shims between the edge of the board and the tube so the board is supported against the tube. The tube then becomes a shooting board of sorts riding along the fence and supporting the board.

[Steve Jenkins]

First step would be to cut it so it is just a bit longer than your final length. I usually roughcut 1" long.Like Larry said place it convex face down on the jointer and use pressure in the middle of the board. This will start to flatten it in the center. a lot of the time a few passes like this will relieve some stress and actually cause the board to flatten more. If it looks like it is straightening out some you can flip it over and joint off both ends a little. by checking the straightness every pass and jointing off the high areas you can usually get things straight and still maintain a decent thickness. Think of your jointer as a really big inverted hand plane. Take off the highs before you try to take a full pass.

[Myk Rian]

What is the best way to face joint a board where there is a high area toward the middle of the board?

My issue is that my regular technigue -- pressure on the outfeed side, but not the infeed side -- can accentuate the problem, because the high point acts as a fulcrum. I end up taking a lot off the front end of the board, nothing off the back, and the high area stays high.
Put pressure on the tail end also until the whole board gets close to flat. Then finish it normally.

[Chip Lindley]

We ARE discussing Face Jointing here aren't we?? Some have given advise for edge jointing it appears. I must disagree with most here, knowing that first trying to take the *belly* out of the middle is very hit or miss as the board can rock front to back.

I would work on the concave side of the board first, so at least TWO points can be referenced on the jointer tables. Place the board over the cutter about midway of the bow, and take light cuts to trim away the concave bow toward the end. Then turn the board end for end, beginning at center and trim toward the other end. Some tearout at this point does not matter!

When the board approaches flatness, take final light cuts *with the grain* to finish the job. The convex side can be run through your thickness planer to achieve a flat board ready for use. Thats my method and I'm stickin' to it!

[Joe Chritz]

Lots of ways to skin that cat.

I would use light pressure on the high spot (which is down on the infeed table) and take a couple passes. Switch pressure to the outfeed as soon as it has cut some and the new surface is riding on the table.

Since the tables are coplanar (or should be) it will always leave a flat surface, even if the pressure is farther back on the infeed side. Once it is closer to flat you can start doing it as normal.

Regardless you will loose thickness when there is a significant belly. I rectangle still has to fit in the entire board as seen from the side. Sometimes it isn't possible to get what you want from a board.

Joe

[Stephen Edwards]

I use Chip's and Larry's method. Works for me. Best of luck! Really, luck doesn't have much to do with it. Rather, it's technique.

Just this past week I had to do the same task. I was working with 2" thick ash in the rough. That was stout enough that I didn't have to *start in the middle* to get one side flat. If you're working with thinner stock, then Chip's and Larry's technique gets my vote, too.

If you have a scrap board laying around that has the same problem you might try some practice runs on that to see what works best for you.

[Chris Padilla]

Chip has it but if the bow is bad, you may wish to just crosscut the board in the middle of the belly and use it for shorter pieces and select another flatter board if you need longer stuff.

I guess it depends on the thickness and how much you're likely to lose....

[Wilbur Pan]

Use a hand plane to knock down most of the belly, and then you'll have an easier time on your jointer. Honestly, this is the easiest way.

Alternatively, if you have a belly on one side of the board, you'll probably have a hollow on the other side. It's usually easier to deal with a hollow on a jointer than a belly. Joint the side with the hollow, and then use a planer to take care of the side with the belly.

[Dewayne Reding]

Chip has it but if the bow is bad, you may wish to just crosscut the board in the middle of the belly and use it for shorter pieces and select another flatter board if you need longer stuff.

I guess it depends on the thickness and how much you're likely to lose....

X2 what Chris and Chip said. I know my skill level on my 6" jointer will not allow me to perform miracles on a bad 5+ foot board. Quickly learning it pays to have enough stock around so you can just cut er in half and make two perfect boards out of the defect, rather than wasting it trying to keep it long. I need me one of them aircraft carrier jointers I guess.

[Don Morris]

I'm still perplexed at the comment about using a TS to cut the belly off first. How do you do that "elegently" with an 8" board? "Concave side down, with two reference points" has worked for me. Putting the belly side down and running that over the blade guys have more talent than me. Sounds neat, though, on some unimportant piece, I'll have to try that.

[Mikail Khan]

I'm still perplexed at the comment about using a TS to cut the belly off first. How do you do that "elegently" with an 8" board?

Post may have referred to a belly on an edge rather than on a face.

MK

[Don Morris]

His post read "How do you FACE joint a board..."

[Richard M. Wolfe]

Face joint the concave side down until that side is flat and then run it through a planer, convex side up. Running it through a planer with only light pressure may do it for both sides (once again doing the concave side down first) unless it removes too much material.

[Mike Parzych]

I always wonder when the word "pressure" is used in regards to jointing. Especially when face jointing a board, it's really easy to flex the board, which is the quickest way to eat up a bunch of stock and still end up with a bellied board.

The "pressure" I use when jointing is verrry slight - just enough to keep the board from hopping up and down. Usually I use no more than my thumb. The concept of jointing is to let the piece "ride" over the knives without distorting the bend/bow you are trying to take out. The board WILL eventually end up flat/straight.

When face jointing bowed stock I'll run the concave side down, and run the front and back ends over the knives - without touching the middle of the bow, until it's pretty close. Then let it ride over the knives the full length - with only MINIMAL pressure on the outfeed side.

If you run a bowed board over the knives, at the outset it should NOT be making contact anywhere in the middle.