Flat Enough?

[Sue Wise]

For those of you who use hand planes to joint the face and then use a thickness planer, how flat does the entire board have to be before you send it through the planer? I ask this because, I only have a 6" jointer and I am tired of ripping a board and then gluing up the panel. (I am also looking for an excuse to buy a good jointer plane if this is a doable option for me.)

[Mark Singer]

It does not need to be 100 percent. You can skip joint the surface and the planer will do the rest. It needs to be free of most warping and this you will learn. At the planner make a light pass and flip it and a light pass. Check it with a straight edge.

[willie sobat]

I flatten my wide stock by hand to send through the planer. My litmus test is to place the hand planed board, planed side down, on my table saw to see if it rocks on the table. If it doesn't then it's good. If it is too long to test on the saw table I use a 48" straight edge and winding sticks.

[Ian Gillis]

Hi

Totally agree with the above. Get the board flat enough so it doesn't rock - smooth and pretty doesn't matter at this point.

I'd just like to add a point that you may already be aware of. Cutting your pieces to rough length before jointing will cut down on the time you need to plane it flat. Also, it reduces the overall amount of material removed and may allow you to get thicker stock, e.g. you MAY be able to get 7/8" boards for a tabletop from 4/4 stock.

This applies equally to machines, but you may want to leave the pieces a bit longer to allow for any snipe or tear-out near the ends.

Cheers
Ian

PS, Nobody will think less of you for buying a bigger jointer

[george wilson]

You can plane a badly warped board by gluing a piece of scrap wood in the hollow part of the warp,and making the thickness of the scrap so that the board will be supported in the center,and on the ends, concave side down on a flat surface. Also,shore up twisted wood at the offending corner if your jointer isn't wide enough to take care of the twist.( You can also take the fence entirely off the jointer, and remove any keyway on its table,and plane off high corners from a 12" wide board,even if you have only a 6" jointer.Just run the board diagonally across the cutter,and plane until the board is REASONABLY flat on the hollow side.) Then,lay the board on a piece of plywood,or a flat plank,and run it through a thickness planer carefully,not taking off a lot,until you have planed the convex side flat. A planer will flatten out a twisted board,plane it,and release it planed and still twisted,if you take a heavy cut. Then,turn the board over,knock off the scrap piece,and plane the hollow side flat. Be aware that planing any board can release tension in the wood,and cause a formerly flat board to start warping. It is best to take equal amounts off both sides of a board.Do not take large amounts off a board in 1 pass. That helps it start to warp. Even boards 100 years old can warp when planed. I knew a guy who planed down a 2" thick antique walnut door to make a 1/2" thick board for a harpsichord lid. It was 2' wide,and took a 3" curve across its width. He took all,or most of the wood off 1 side,and probably took heavy passes off of it. Wood never stops responding to stress until it rots.

[Tristan Raymond]

PS, Nobody will think less of you for buying a bigger jointer

Agreed, go for the No 8 instead of a No 7

[Frank Drew]

Sue,

For the purposes of getting it flat enough to run through your planer, you can face joint a board almost twice as wide as your jointer's cutterhead by flipping the board end for end every other cut (but keeping the same face down). In other words, you can prepare an 11-3/4"+ board on your 6" jointer.

In either machine or hand face planing, if you only need to get a flat enough surface to ride through the planer without deflecting then it doesn't have to be pretty and in a reasonably thick board a little bit of a hollow left between two broad flat areas won't be pressed out running through the planer.

[Sue Wise]

Thanks for all of the suggestions. I am going them a try. I was taught that it needed to be perfect before the planer, but I think all of you are correct that it needs to be flat enough to that it does not deflect. No room or money for a bigger power jointer, so I will take my homemade Jack out, sharpen up the blade and give it a go. (I will also try taking the guard of my power jointer and try that also.)

-Sue

[george wilson]

Of course,keep your hands away from the blades,and be careful of any kickback. I am sure someone will give me flack for suggesting that the guard and fence be removed from the jointer,but this is the only way to accomplish planing the wind out of wide boards.With common sense it can be done safely. Another thought,You could get one of the hand held power planers and flatten boards with it. I have a Bosch that I can jam a Fein vacuum's hose into. Works great.

By the way,I am assuming that there is NOTHING else sticking up beyond the height of the cutterhead,such as a drive pulley,before suggesting to use the jointer in this way.

[Sue Wise]

George,
I am not going to take fence off, but just the guard. I will try face jointing one side of the board and then the other and see what happens. Although the boards I have now are pretty good, so I may just take a hand plane to them if needed.

-Sue

[george wilson]

George,
I am not going to take fence off, but just the guard. I will try face jointing one side of the board and then the other and see what happens. Although the boards I have now are pretty good, so I may just take a hand plane to them if needed.

-Sue

Lowe's sells the bosch electric plane very reasonably. It does wonders for me.

[Joe Chritz]

The answers for "no rocking" is spot on. I have several times just knocked a high spot off a board so I could run it through when I needed something a bit over 8" wide.

Essentially that is all a planer sled does is support the board at the low areas so it doesn't rock and gives a flat face to then run down.

This is one of the main uses of my longer torsion box when I have to run longer pieces and don't want to do any glue up. It is great to set the board down and see the whole thing sit nice and flat before running it through the planer.

Joe

[willie sobat]

I have tried the technique of using a 6" jointer to flatten boards wider than 6" before. It only worked (badly) for me with bows. It did not work for cups or especially twists. In those cases that technique didn't help or worse magnified the problem.

[george wilson]

Willie,the technique I mentioned isn't for attaining any real accuracy. It's just for getting a board reasonably flat enough not to rock around when you run it through a planer. It,being a freehand process,does require some personal judgement and skill development for success. Personally,I am so disabled that I'd much rather use the freehand jointer,or an electric handplane than to hand plane a big board down like I used to. Just be careful where,and how much you take off.

[Jay Knoll]

Another way to flatten a board wider than the jointer is to flatten the width you can, on one face -- kind of like a wide rabbet. Then make a MDF sled for your planer, about an 1" wider than your rabbet, put your board on it jointed side down and run it through your planer to flatten the other face. When that is done, turn it over and flatten the other face, removing the proud part of the "rabbet"

Jay