Squaring Boards by Hand

[Tom M King]

You don't need to focus on a winding stick. Get your eye in a position so you can see over the near one, to under the far one. Raise, and lower your eye enough to judge the gap you see. When the gap closes simultaneously, from one end to the other, the ends are co-planar. If the gap closes on one end before the other, the reason is obvious. You can focus on something beyond the gap, but I've never thought about what I'm focusing on.

I like no. 6's for flattening. I ended up with two by chance, but like the way they follow each other. One takes a shaving about 12-13 thou, and the second one half that. If something is terribly out of flat, the no. 5 starts.

[Mark Hennebury]

Hi,

apparently I must be missing something; because I don't understand your statement. "there is no front or back to a flat surface."
I was referring to the difficulty being able to see both winding sticks, the one closest to you and the one farthest away from you.

The 0.001" was for reference, you can use 1/16" or a 1/2" you can work to whatever tolerance you want, it doesn't matter, the fact is you have no way of measuring with winding sticks, you can only guess.

It does not matter which one you focus on, there is no front or back to a flat surface.

What is the point of getting a 0.001" accuracy on a slab of wood? What woodworker works by specifying mils in their measurements?

[Mark Hennebury]

If you have got nothing......

If you don't understand the few arguments I gave, there is no point in supplying more.

[Tom Mayock]

I will take a crack at the straight-edge only approach this weekend. I have a mathematical background, and I have no problem with the coplanar concept. I think my issue at this point is using the reference surface to inform me about what material needs to be removed that is causing most of the problems.

I am also working on a rather odd work bench that the previous owner left in the garage. The workbench is basically a base cabinet that is installed against the wall with a laminated top on it. The 5 inches or so of the top that are away from the wall (and thus the most accessible part of the bench) are not coplanar with the rest of the table and slope down at an angle of 1-2 degrees. This makes holding and stabilizing work... challenging.

When people say that something is flat within a X millimeters, how do people typically make this assessment with hand tools? Do you just sweep the straightedge around the table and check with the feeler gauge in a few points?

[Mark Hennebury]

I don't usually use a feeler gauge when planing a table top. I mentioned a feeler gauge as an example of being able to measure the deviation, but it is not necessary to know any measurement, you have to take off what you have to take of to get it flat.
So I would examine the top and imagine how I would get a top and bottom surface flat and parallel and get the maximum thickness out of the board.
So this requires a bit of judgement, and practice. You have to image two parallel planes slicing through all of the peaks, skimming the valleys, removing the minimum amount necessary, to leave you with the thickest flat board.
It's a fun challenge to imagine the plane, and to "see" where you need to remove material.
You can of course place a twisted board on a flat surface and shim it, and measure how much, or scribe around from the flat, though that is not something that I do. Once you have a flat surface, you can scribe the other side from your flat surface to produce your parallel planed second surface.
This is the skill that you gain from doing. You use the same principles for dressing lumber with machines like jointers and thicknessplaners. You can't just push a twisted board over a joiner and expect it to come out flat. You can put a twisted board on a sled, shim it and secure it and feed it through a thickness planer and get a nice flat planed surface. Your judgement improves with practice.
Just experiment, you will figure out what works for your needs at this time, be open to challenging your own ideas.

Woodworking is easy; wood is easy to understand, tools and machines are easy, humans are difficult. The hardest part about learning woodwork, is seeing past our own prejudice.

I will take a crack at the straight-edge only approach this weekend. I have a mathematical background, and I have no problem with the coplanar concept. I think my issue at this point is using the reference surface to inform me about what material needs to be removed that is causing most of the problems.

I am also working on a rather odd work bench that the previous owner left in the garage. The workbench is basically a base cabinet that is installed against the wall with a laminated top on it. The 5 inches or so of the top that are away from the wall (and thus the most accessible part of the bench) are not coplanar with the rest of the table and slope down at an angle of 1-2 degrees. This makes holding and stabilizing work... challenging.

When people say that something is flat within a X millimeters, how do people typically make this assessment with hand tools? Do you just sweep the straightedge around the table and check with the feeler gauge in a few points?

[Steve Voigt]

Now take your winding sticks….. throw them away…. and get yourself a good straight edge!

This is terrible advice. Why would you advise someone to throw away the traditional, proven tool for dealing with twist?

There is a reason workers in the 17th, 18th and early 19th centuries used winding sticks. They had a lot more experience actually planing wood. Using a straightedge on the diagonals is a very clumsy way to gauge the wind in a board. The winding sticks are often longer than the board is wide, so in addition to gauging wind more directly, they accentuate the error. This is especially true when preparing edges for gluing.

Warren is 100% right here. I can only surmise that people who don't use winding sticks simply never figured out how to use them. Once you get the hang of them, they are faster and easier than the makeshift methods people resort to.

My advice is to learn the traditional methods people have used for hundreds of years; as Warren says, there is a good reason these methods have persisted.

[Warren Mickley]

I will take a crack at the straight-edge only approach this weekend. I have a mathematical background, and I have no problem with the coplanar concept. I think my issue at this point is using the reference surface to inform me about what material needs to be removed that is causing most of the problems.

I am also working on a rather odd work bench that the previous owner left in the garage. The workbench is basically a base cabinet that is installed against the wall with a laminated top on it. The 5 inches or so of the top that are away from the wall (and thus the most accessible part of the bench) are not coplanar with the rest of the table and slope down at an angle of 1-2 degrees. This makes holding and stabilizing work... challenging.

When people say that something is flat within a X millimeters, how do people typically make this assessment with hand tools? Do you just sweep the straightedge around the table and check with the feeler gauge in a few points?

I think that when people say that the surface of a board is flat to within a certain tolerance, it is likely that they don't have a mathematical background like you.

The traditional method is to use straightedge and winding sticks to evaluate the surface. With long pieces we use the winding sticks at both ends and one or more intermediate points as well. Part of the skill is to translate that information into a map of the surface in your mind. And part of the skill is to have a feel for how much planing in what areas will bring you to a point where your next inspection will show a much flatter surface.

The narrower the piece is, the less effective it to use a straightedge on the diagonals, while the winding sticks accentuate the twist. This especially helpful when making a frame construction, for example. A small twist in one member will make the frame twist to a much greater degree.

[Rob Young]

Hey Warren,


"so in addition to gauging wind" How exactly do winding sticks gauge anything? You put one on one end of a table top and one on the other and you focus on which one? If you focus on the near one, the far one is out of focus, and visa versa. So you make a guess. To what degree of accuracy do you guess to?

You need to be further back from the winding sticks if you can't hold a focus that shows both clearly. Or update your prescription.

[lowell holmes]

I was going to comment but you guys have covered it. I do mark the end of the board with a tri square and then scribe the cut line with a knife.

https://search.yahoo.com/search?fr=m...utility+knives

[Mark Hennebury]

Hi Steve,

I thought that it was quite funny actually.

Warren may be 100% right, I am not an authority on anything, just throwing my two cents in to shake it up, to help people to question and experiment. I am as human as the rest, and as such just as full of all that good human bias. You shouldn't believe a word that I say.

This is terrible advice. Why would you advise someone to throw away the traditional, proven tool for dealing with twist?


Warren is 100% right here. I can only surmise that people who don't use winding sticks simply never figured out how to use them. Once you get the hang of them, they are faster and easier than the makeshift methods people resort to.

My advice is to learn the traditional methods people have used for hundreds of years; as Warren says, there is a good reason these methods have persisted.

[Mark Hennebury]

I recently got glasses.... Now, if I can only remember where I put them....

You need to be further back from the winding sticks if you can't hold a focus that shows both clearly. Or update your prescription.

[Rob Young]

I recently got glasses.... Now, if I can only remember where I put them....

Check the top of your head...

It got more annoying when I finally got bifocals (continuous vision type) after 30+ years of wearing glasses.

Other than the glasses issue, I find that I need to be back at least the distance between the two sticks with a lower limit of 3 feet to be able to focus on both. So if I have them 4 feet apart I need to be about 4 feet back from the nearest winding stick. But if they sticks were say 14" apart I would still need to be about 3 feet back of the closest stick. YMMV.

[Oskar Sedell]

just to add what has been already said. Winding sticks are more universal than a straight edge and can be used in many instances. As have been said, on narrow boards any difference on diagonals might be hard to discern with a straight edge, while exaggerated with winding sticks. And there will always be the case of the board longer than your longest straight edge. Winding sticks are the same to any length of board.

[Dennis Droege]

Tom, this isn't intended as advice, but it works for me in a certain situation: I make small wooden boxes with dovetailed joints, and it's necessary that all my pieces be flat, parallel and square. When I see that one piece has a little 'rock' (is this the origin of the 'tap test'?), I have had excellent luck with placing a piece of carbon paper on a good flat surface, carbon side up, and drawing the piece I want to flatten across it. Minor smudging gets minor planing, then do it again--I take a certain joy in seeing the 'rock' diminish until the piece is flat. Best to you.

[Jim Koepke]

Tom, Here is a post of mine > https://sawmillcreek.org/showthread.php?272588 < it includes using different methods of checking different pieces for flat.

Winding sticks by necessity are straight edges. Another way to make a straight edge as long as you want is to use a tightly strung piece of string. This method is also used in the link above. The project is still ongoing. Due to many other things my time on it has been restricted. Hopefully it will be finished this year.

Here is a post on making straight edges and winding sticks > https://sawmillcreek.org/showthread.php?290331

Amazingly, making a straight edge for yourself will give you insight in how to produce a straight edge or a flat surface. It is kind of practice, training and accomplishment all in one.

Good luck with your endeavors,

jtk