Tuesday, January 12, 2010

No Winding Sticks? No Worries!

If you're working with long boards, you'll probably want to make a set of winding sticks. But if you're working with shorter pieces, here is the method I use to remove twist and flatten a board.

Lay your board on a dead flat surface—I use my table saw. Touch one corner with your finger and then the opposing corner. Then do the same with the other two corners. If the board rocks with one set of corners, it's not flat. And depending on which corners are rocking, you can tell where the high spots are.

High corners will not rock, low corners will. Remove high spots with your handplane and keep checking the board on your flat surface. Sight along the bottom edge of the board to see where it is and isn't touching the flat surface. This will also reveal high and low spots. Continue to plane and check your board until it no longer rocks when you touch oppposing corners and when the bottom edges of your board lay seamlessly on the flat surface.

In addition, I use a backlit straight edge to check for flatness by laying it diagonally across the board in both directions, and along the width and length of the board, parallel to its edges.

These methods have always worked well for me and actually seem to work most effectively when I use them before cutting the joinery. Go figure.


Shannon said...

Yay the Sawbuck table is coming back???

Kari Hultman said...

It is, indeed! I figured a year was long enough to put it on hold. haha

Woodbloke said...

Hi Kari - I assume the boards were true when you started cutting the joints?
Good way of checking for true boards, especially if the ci tablesaw surface is flat...some arn't! - Rob

Darnell said...

Wow, I can see why you want to salvage that front, that's really pretty.
There is a technique that a buddy of mine calls a "reverse bent lamination". Resaw a crooked board and glue it back together in a vaccuum bag on a flat platen.
Or do you already have a strategy?

Kari Hultman said...

Rob, never assume! haha No, I'm sharing a major boo-boo with you guys. A friend once accused me of never showing my mistakes. Well, here you go. ; )

Darnell, I wasn't aware of that technique. Does it really work? I had heard of lamenating two separate boards together for rails and stiles to combat twist.

With this board, I decided to go ahead and flatten it and then shim the dovetails. It'll be okay. Plus, it's a primitive piece, so I'll call the mistakes "character."

Darnell said...

Ya, it works great. I've never used the unbent lamination technique on a finished piece, though, keeping it aligned would be tough. I do it mostly when I resaw 8/4 stock and internal stresses turn my boards into bananas.