Flattening a twisted board

[jsollows]

I'm new to hand planes and am struggling with flattening a twisted board.

Placing the board flat on the flat benchtop, I'm able to rock the board in this direction B to D.

In this direction A to C, the board is flat, there is no rock.

How would you determine where to plane so that you make the board completely flat?

[Beechwood Chip]

Or, A and C are resting on the table but the center is off the table because there is a cup from A to C. It's flat from B to D, but the board rocks because the cup from A to C lifts the center off the table.

I think you need to use winding sticks to find out what's really going on. There may be other tricks - I'm not a neander.

[lwllms]

I keep some 16" long tapered shims on my bench. I'd shim B and D until the board was stable. Plane diagonally generally in the direction of B/D which are the high spots. After you start getting full length shavings begin working the whole piece. The length of your plane will work with you, there's a reason for the lengths of bench planes used in a traditional manner. I doubt those who say a jack or jointer can do it all are actually preparing stock by hand. While it's a good idea to check progress with a straight edge, with the grain, across the grain and diagonally; the plane is perfectly capable of telling you when you're close by full-length and full width shavings. A little experience helps here. Start with a fore or jack plane and get your finish, if you can with a trying plane. The most true surface you should expect is from a trying plane unless your work is very long and you need a jointer. The smooth plane actually is intended to reduce the visual impact of imperfections by spreading them out over a wider area. That said, I don't understand today's fad for extra wide road-grader sized smooth planes. Wide smooth planes limit control and have no versatility.

BTW, stock selection is the first step in stock preparation. That knot with the black bark outline will be very prone to popping free. Do you actually need the full width of this piece?

[jsollows]

I keep some 16" long tapered shims on my bench. I'd shim B and D until the board was stable. Plane diagonally generally in the direction of B/D which are the high spots. After you start getting full length shavings begin working the whole piece. The length of your plane will work with you, there's a reason for the lengths of bench planes used in a traditional manner. I doubt those who say a jack or jointer can do it all are actually preparing stock by hand. While it's a good idea to check progress with a straight edge, with the grain, across the grain and diagonally; the plane is perfectly capable of telling you when you're close by full-length and full width shavings. A little experience helps here. Start with a fore or jack plane and get your finish, if you can with a trying plane. The most true surface you should expect is from a trying plane unless your work is very long and you need a jointer. The smooth plane actually is intended to reduce the visual impact of imperfections by spreading them out over a wider area. That said, I don't understand today's fad for extra wide road-grader sized smooth planes. Wide smooth planes limit control and have no versatility.

BTW, stock selection is the first step in stock preparation. That knot with the black bark outline will be very prone to popping free. Do you actually need the full width of this piece?

Thanks for the reply. The stock is just being used for practice planing purposes so the knot isn't an issue.

[Bob Rozaieski]

I'm new to hand planes and am struggling with flattening a twisted board.

How would you determine where to plane so that you make the board completely flat?

Here's a podcast I did on the subject. You need to use a pair of winding sticks to determine where the twist is. Don't rely on your bench, which may not be perfectly flat. The sticks can be any piece of straight wood with parallel edges. They don't have to be pretty. Any scrap will do as long as they are straight and the edges are parallel. You can even use aluminum angle from the home center. Find the high corners, then plane diagonally to remove the twist. As Larry said, you can shim the corners to prevent the stock from rocking while you plane.

Episode # 27: Flat & Square

[jlloydparks]

Larry is spot on. I use shims a lot to help keep the piece from rocking when I plane. Plus a full length and width shaving helps show you are on track, but stop when you reach that point and recheck the board else you could bring the corners B&D down and then A&C will be your high spots and you can chase your tail for while this way. I have found that more deliberate planing and stopping to check is faster and more accurate than wildly planing away at a board because it is easy to take off too much quickly.

I also use winding sticks to identify my high and low spots. See my post back here on how they work. They also make excellent straight edges.

[jsollows]

Here's a podcast I did on the subject. You need to use a pair of winding sticks to determine where the twist is. Don't rely on your bench, which may not be perfectly flat. The sticks can be any piece of straight wood with parallel edges. They don't have to be pretty. Any scrap will do as long as they are straight and the edges are parallel. You can even use aluminum angle from the home center. Find the high corners, then plane diagonally to remove the twist. As Larry said, you can shim the corners to prevent the stock from rocking while you plane.

Episode # 27: Flat & Square

Thank Bob, this is awesome! I've not seen your podcast before but I'm changing that ... I just subscribed and will be watching all of them.