Flat, square, IMPOSSIBLE!?

[Michael J Evans]

I cannot plane wood flat / square across and along its length. I've tried and tried and tried. I've watched multiple videos multiple times and can't understand why I can't do it.

My usual process starts by going across the grain then diagonal then along the grain. Then Checking for twist / fixing that. I can usually accomplish flat across, the problem then comes when I try to flatten along the grain. After I get it reasonably flat along the grain then it's no longer flat across or I've put twist back into it. Maybe I'm being to picky about flatness both ways, I hold my straight edge or square up to my shop lights to check and there's always some gap. When the straight edge isn't held up to the light its usually all good.

Is there such a thing as flat / good enough?
I literally just planed off a 1/2" of a supposed to be 1.5" top trying to get it right and am going crazy every time I try to dimension wood.

[steven c newman]

First...RELAX, wood moves..

Next, use the longest plane you have, and get the high points.

Scribe a line all around the edges, to show WHERE you want to wind up at. Plane til you barely nick the lines.

[Warren Mickley]

You have to make a mental image of the surface, noting the highs and lows. Then the low spots should not be planed at all unless maybe once at the end for uniformity. Just plane the high spots. For instance if there is twist and the near right corner and far left corner are low, you can plane the opposite diagonal, or right down the middle, but don't plane lthe diagonal that contains the low corners at all. Try marking low spots with chalk and make sure they are not touched.

[Robert Engel]

What kind of planes are you using? Once you get the board laying flat put that face down. Once you get the twist out use a #6 or 7 plane to go across the board. If you're using a #4 plane this is where your problem is.

I've learned you have to use winding sticks several places along the length not just on each end like you see a lot of guys do. This will tell you where to mark the high spots. Once you get close take 2 or 3 shavings at a time.

I also use a long straight edge to check lengthwise. You can buy an expensive straight edge but I just use a level on longer boards.

Flat enough is very subjective. Its however flat it needs to be. Sorry.

[Nicholas Lawrence]

Is there such a thing as flat / good enough?

Yes.

Also, Warren is giving you good advice.

The videos where they mindlessly plane the whole thing and it somehow miraculously gets flat and square make me laugh. I have always suspected somewhere in the middle they run it over a jointer or something.

Paul Sellers has a free video (or maybe two) where he flattens and squares a board of reasonable size. It is the most realistic one I have seen, and might help.

Finally, don't get discouraged.

[Matthew Hutchinson477]

Ah, I remember these days. It took me a longer time than I'd like to admit to figure out how to plane a board flat. I once took a 3/4" thick piece of oak down to less than 1/2" just trying to get the damn thing flat...

At first I kept getting hollows, which is weird. Turns out that holding thinner pieces in a vise rather than on a dead-flat surface where they're fully supported was the culprit. As for taking out twist, my big error was just using the winding sticks to check twist at either end, and traversing all the way across. If the twist is consistent then that's fine but sometimes it isn't. I figured my plane would skip over the low spots and take off the high spots thus making the board more flat on its own. That only works if you take thin enough shavings, use a long enough plane, and make sure the plane's sole is actually flat.

In the end, the rule seems to be (so far) to just check more parts of the board with your straight edge, and be more meticulous in marking high or low spots, be more selective with where you plane (i.e. only plane the high spots), and taking thinner or less shavings as you get closer.

Videos and books shorten the learning curve better than anything else I found, with the exception of meeting someone who actually knows what they're doing and working with them.

[Simon MacGowen]

I cannot plane wood flat / square across and along its length. I've tried and tried and tried. I've watched multiple videos multiple times and can't understand why I can't do it.

I can understand your frustrations and despite all the comments you may have read by now, I very much doubt they will make a difference to you. It is simple in principle like removing the high spots, etc., but in practice it is not that simple as many factors can affect the results.

Assuming you had your plane set properly (were you sure?), did you know if you tend to tilt your plane inward or outward? Did you tend to put much pressure on the handle when you started?

Have you seen Rob Cosman do it? Even he has to spend a good amount of time on flattening a board that is not large, say, 1' x 2' or so. (But I don't like the way he checks the flatness on the bench, I prefer the winding sticks.)

I don't have the answer to your question, but a suggestion. While you can keep trying (and keep getting frustrated), following all the advice others have given you here, I strongly suggest that you get an in-person tutorial from a plane user who can plane true and square. Let him or her watch how you do it and then show his or her techniques. You need immediate feedback on what is right and what is wrong to make and see immediate improvements. No second guessing.

You can watch hundreds of videos or read articles (at least over a dozen have been published) but can still not plane a board flat consistently. On two subjects, I always recommend people take a class or get help in person: Flattening boards, and cutting dovetails.

One last thing. Wood moves and a board flattened may no longer be so if you leave it in your shop after a couple of days that has acute humidity swings.

Simon

[Brian Holcombe]

Take Warren's advice, and I go over it a bit in some of my YouTube videos.

[James Pallas]

I was once told, "You learned how to do this a long time ago. When you learned to take s stick and flatten the sand in your sandbox."
Jim

[Patrick Chase]

Ah, I remember these days. It took me a longer time than I'd like to admit to figure out how to plane a board flat. I once took a 3/4" thick piece of oak down to less than 1/2" just trying to get the damn thing flat...

Been there, done that.

At first I kept getting hollows, which is weird. Turns out that holding thinner pieces in a vise rather than on a dead-flat surface where they're fully supported was the culprit.

Also been there, also did that.

Pro tip: If your bench isn't flat, then the board may end up the inverse of its profile (did that once, too).

As for taking out twist, my big error was just using the winding sticks to check twist at either end, and traversing all the way across. If the twist is consistent then that's fine but sometimes it isn't. I figured my plane would skip over the low spots and take off the high spots thus making the board more flat on its own. That only works if you take thin enough shavings, use a long enough plane, and make sure the plane's sole is actually flat.

In the end, the rule seems to be (so far) to just check more parts of the board with your straight edge, and be more meticulous in marking high or low spots, be more selective with where you plane (i.e. only plane the high spots), and taking thinner or less shavings as you get closer

Yep. Warren put it well. You can rely on the plane to "blindly" flatten things along a single axis (for example for edge jointing), but to get both you have to identify and specifically work the high spots.

[Stanley Covington]

Warren has the right of it.

The hard truth is that you are not paying attention. Everyone has the exact same problem at first. Some realize it sooner than others.

Your primary tools are brain, hand and eye. And even ear when your skills become more advanced. Use all of them, not just hand.

Your plane is your secondary tool. The plane's blade is what cuts, not its body, so pay attention to where the blade is when cutting.

Pay careful attention to the board as-is, and compare it to what the finished board needs to be. Sounds so easy, but most people screw this up to one degree or another. It takes a conscious effort. A long ruler and winding sticks will help you see and think and plan. The plan may need to change frequently. Do it.

There are high spots, there are low spots. A plane can't raise low spots, but only lower high spots. You need to pay attention and see the high and low spots. Cross thatch the entire surface of the board with chalk, lumber crayon, or pencil. Circle the high spots. This will help your eye and brain tools pay attention.

Take small short strokes with your plane. Just a couple of inches. ONLY on the high spots. After a couple of strokes (not 6 just 2), check with ruler and winding sticks. Make your eyes see the progress. Notice how the low areas stay cross-thatched, and the high areas are being shaved. Adjust the plan. Re-mark. Repeat.

Sometimes you will make it worse. When that happens, STOP. Use ruler and winding sticks to help your eye tools see the problem, then use your brain tool and figure out why. You must figure out the process that made things worse. Once you figure it out, then you are learning. Don't make the same mistake again.

Stop taking long strokes. They feel like they are accomplishing more, but you stop paying attention and cut wood that doesn't need cutting. When you learn how to pay attention with eye and brain, then your hand will quickly develop the ability to feel how and where the blade is cutting. After this, long strokes can be useful. But not yet.

The pressure of the plane will make the board's hollow areas deflect down a tiny amount away from the blade. Not good. Same thing happens if the supporting surface is not flat. Use a flat surface.

Use shavings, newspaper, cardboard, or even strips of wood, depending on the degree, to shim and keep hollowed areas/corners from deflecting down or rocking.

[john zulu]

I cannot plane wood flat / square across and along its length. I've tried and tried and tried. I've watched multiple videos multiple times and can't understand why I can't do it.

My usual process starts by going across the grain then diagonal then along the grain. Then Checking for twist / fixing that. I can usually accomplish flat across, the problem then comes when I try to flatten along the grain. After I get it reasonably flat along the grain then it's no longer flat across or I've put twist back into it. Maybe I'm being to picky about flatness both ways, I hold my straight edge or square up to my shop lights to check and there's always some gap. When the straight edge isn't held up to the light its usually all good.

Is there such a thing as flat / good enough?
I literally just planed off a 1/2" of a supposed to be 1.5" top trying to get it right and am going crazy every time I try to dimension wood.

Are you applying machining techniques to wood working?

[Michael J Evans]

You have to make a mental image of the surface, noting the highs and lows. Then the low spots should not be planed at all unless maybe once at the end for uniformity. Just plane the high spots. For instance if there is twist and the near right corner and far left corner are low, you can plane the opposite diagonal, or right down the middle, but don't plane lthe diagonal that contains the low corners at all. Try marking low spots with chalk and make sure they are not touched.

Thanks Warren

[Michael J Evans]

Yes.

Also, Warren is giving you good advice.

The videos where they mindlessly plane the whole thing and it somehow miraculously gets flat and square make me laugh. I have always suspected somewhere in the middle they run it over a jointer or something.

Paul Sellers has a free video (or maybe two) where he flattens and squares a board of reasonable size. It is the most realistic one I have seen, and might help.

Finally, don't get discouraged.

Pauls video is a good one and one I've watched literally 15 times or more. I really hate giving up on something, so after a frustrating session I usually watch a video to think about what I'm doing wrong.

[Michael J Evans]

Brian,
I didn't know you had videos, will looks those up.