06 December 2012

Fast Wood

This week The New Yankee Online presented a Desk Top Writing Case.  I like the programs even if my recurring impression is that many projects could be done without a stacked dado blade and simply with biscuits.  This project is a compromise,  where the sides of the box are finger jointed with ... a stacked dado blade (he could have joined them with biscuits:). But the breadboard edges of the desktop are made with pinned biscuits,  a technique I hadn't seen before.

He first shows us the original English desk top writing case with a top with breadboard edges and two cracks: One at the junction of two boards, those are pulled apart by the nailed breadboard edge.  And a second crack in the corner at the top where the hinges pulled and the breadboard pushed

His solution is to use biscuits set off center,  the narrow side glued and the other pinned through a slot to allow seasonal movements.

The same cross-grain problem gets another solution for the bottom of the box. Screws and slotted holes are used there.

Looking at what Chris Schwarz has to say talking about cross-grain construction in six-board chests,  nailing is good enough for softwood.  The cracks seen in the antique example could then be attributed to the fact that the wood was not dry enough when making the writing case.  

Personally I like biscuits because they are wooden fasteners and are also fast and relatively easy to use. They are even so fast that if Norm Abram had used them more, the program would probably have been ended within two seasons.
Making a six-board chest with biscuits needs only special care at the junction of front and back to the sides.  Using the pinned biscuits solves most problems, where the junction with the lid and bottom remains a problem.  I suppose that not attaching them close to the corners solves this.  This is setting the hinges away from the sides and not attaching the bottom close to the ends of the front and back.