Wednesday, October 7, 2009

St. Roy's Dovetail Seminar

video
Roy Underhill's dovetail presentation at the WIA conference was entertaining, informative, and entertaining.

He began with a discussion on what we know today as the do's and don'ts of dovetailing, and proceeded to show us an early 19th c. tool box that broke all the rules.

Then he passed the behemoth box around the room.

A little trick he told us for identifying the date of a piece is to examine the screws. If they are pointed on the ends, they were machine made after 1846.

For laying out dovetails on the tail board, use your chisel as the ruler. The width of your chisel should equal the widest part of the pins. Strike a chisel mark on the gauge line on the furthest edges of the face of the board. Then strike chisel marks between them to layout the remaining pins.

Use a bevel gauge to determine the pins' angles. Roy does not use a dovetail marker; he adjusts the angle until it looks good to his eye. A try square is used to mark the end grain, and a handsaw lays in the kerfs.

To transfer the marks to the pin board, drop a handsaw down into the kerf, then pull back with a light touch. Don't make a deep mark, because you'll need to saw beside this mark, not on it. (This is in the video.) You can draw a pencil line in this groove so you can see it better.

Roy uses a chisel to remove waste only at the base of each pin on both sides of the board. The remaining chip, above the chiseled-out section is merely pushed out. He uses a coping saw to remove the bulk of the waste on the tails, however.

Rule of thumb, he said, is that the widest part of the pin should be half the thickness of your board. Tails, at their widest part, should be almost twice the thickness of the board.

Towards the end of the video are some shots of the Thomas Jefferson book stand that Roy built.

The photos above are some of the dovetail puzzles he passed around and which befuddled my little pea brain. As if sitting right beside where Roy was standing wasn't enough to make my brain all mushy.

Music: Big Rock Candy Mountain, by Harry McClintock