Best way to flatten boards by hand

Question

I'm trying to process 4/4 soft maple rough stock into 1/2" thin boards, ready for use in furniture and I'm having a real hard time getting them flat. Here's my process so far:

1. Crosscut a 18" piece from the rough stock, about 12" wide
2. Rip this piece in half for roughly the final width I'll need
3. Resaw each of these pieces so they're roughly 1/2" thick
4. Try to flatten the board with my #4 plane, end up chasing my tail and never getting it flat

I should mention that I'm only using hand tools for the entire process, and all sawing is done with a Japanese ryoba (example).

I know one issue I'll have to sort out is holding the work while planing, but what planing techniques could I be missing? I generally start out going diagonal to the grain which gets me fairly close to flat. Then I'll start going along the grain, but I never get completely flat.

EDIT: Here are some pictures of the sole of my plane:

Also, it's a #4, not a #5 as I said earlier. The sole is completely flat according to my measurements. I don't see any nicks in the iron. I do see a fair number of scratches on the sole and I'm not sure what's causing those.

Answer 1

You are a brave individual--attempting to hand plane. I've successfully hand-planed my workbench and here was my method:

1. Use two totally flat sticks (winding sticks) on each end of the board to identify twist. If there is twist, begin by skimming from the high surfaces.

2. Starting at one end of the board, stretch one stick across the grain and look for light beneath. Mark the high spots with a pencil and skim that part (I went diagonal with the grain) until you see little or no light beneath the stick.

3. Move the stick several inches and repeat.

4. Repeat the same process, but lay the sticks in the direction of the grain.

5. Finish with one final pass across the entire board, with the grain.

A couple of reasons why it might not be working:

1. The sole of your plane isn't flat. Have you checked that the #5 if completely flat? If not, rubbing it on a piece of sandpaper on a flat surface should do the trick.

2. The plane may not be large enough. I wouldn't think this would be an issue with only 18 in boards, but #5s are smoothing planes (if I remember correctly). You may want to try a jack plane (although, a 22 in jack plane on an 18 in board may be interesting....do take a picture so we can laugh at you :))

3. The blade itself has nicks? You mention in your comment that there's uneven bumps on the surface. Do you have plane tracks? If so, it might be that you don't have a camber, too much of a camber, or nicks in the blade.

Answer 2

but I never get completely flat.

We're not supposed to ask questions but normally I'd ask here in what way(s) your boards aren't flat after planing with the no. 4. If you can identify a consistent out-of-flat condition to the boards after planing this is a much easier fix than to suggest all the possible ways to maintain flat during hand-planing operations.

If it's a simple case of what used to be called "dubbing over", which is low leading edge and trailing edge, application of the proper hand pressure during planing should help resolve this (along with regular checking of your progress).

When starting the cut, press down firmly on the toe of the plane with the secondary hand grasping the knob; this helps keep the plane flat to the wood as the cut starts. During the cut pressure is lessened on that leading hand until no pressure is applied at the knob at all by the end, with the dominant hand pushing down and forward to complete the cut. Some guides suggest you think of the plane 'taking off' as you leave the surface of the board.

This page, Handplaning 101, and this page, Using a Bench Plane, have similar advice and more that may be of further help. You might also find this four-page article from a 1948 issue of Popular Science a useful read, called Surfacing a Board by Hand.

I know one issue I'll have to sort out is holding the work while planing

There are a great many simple tips for keeping a board in place for planing. One of the easiest is just to drive two screws into the workbench top. The edge of the screw heads dig into the end grain of the board and keeps it remarkable stable. This method has the advantage that you can screw in or back off the screws to vary their holding height for various thicknesses of stock.

But of course you may not wish to have screws in the surface of your workbench so an alternative to this is to make a simple planing stop (or more than one, of varying heights) from strips of wood or ply of suitable thicknesses, that you hold in place with the leg or face vice, or with clamps.

To add greater stability to the board during cross planing operations you need to hold the rear of the board too and perhaps the best method for this is using a notched batten which is held firmly with a holdfast as shown, or with any suitable clamp. This can be used in conjunction with the above two methods or with any bench dog or other slid-up stop.

Answer 3

I hesitate to jump in here because I don't have any data to add. The previous answers give the proper procedure for flattening and although I have done it, I have not experienced your specific problem.

I can only add that traditionally, a #4 (in the Stanley numbering system) is used for final smoothing. Flattening would usually be done by a #7 or #8. I'm not sure about the #6; perhaps its design was a compromise between those two extremes.

I have had problems in the past with a #4 leaving a track or line where one corner of the iron dug in but this doesn't seem to be what you describe.

But since a #4 is relatively short, you could possibly see a non-flat surface. I need to edit this later with a link to an explanation of why a long-soled plane works better for flattening.

Answer 4

Winding sticks will help to exaggerate twist or cup issues and make them easier to see. Shining a light underneath a thin straight edge, such as a ruler, ID's hi and low spots, which you mark with a pencil and work on. Start with your #6 plane vs the #4. The #4 is a smoother, for after the board is flat.

Depending on how you are going to use the boards, it may be best to get kinda flat, put the boards in place, the finish shaping/flattening everything.