24 January 2010

Tenon shootout

I looked at the Fine Woodworking Tenon Shootout: Hand vs. Power Tools  to get a few ideas about tenon and mortise technique.
I pass for the power tools part as it was done with a dado blade on a table saw.  For now the only item that is not on my buying list, is a table saw, as it looks scary, although it has a great sound compared to handheld power tools.  Unless I put the dado blade on a radial arm saw?  No, no no I .... have not enough room.

The hand made tenons where made slowly.  I had expected some Rob Cosman speed and focus on the task, to match the power tools cutting speed, but no.  Much time was refining the tenon with a shoulder plane.  And possibly most of it pushing and pulling the tenon in and out the mortise as the tenon was fitted deeper and deeper.
I looked for older texts to get a better overview of handmade tenons and found some.  Frank Klausz probably summarises it best, in a more recent text,  by saying that no finishing is needed on a tenon as rough wood presents a better gluing surface. So the saw marks can stay, as they improve the gluing process.  The fitting should be between feather light and mallet fit-able.  Fitting, when needed (as it is beginner stuff), is done with a rasp.  The good news is that I can cross those expensive shoulder planes of my buying list, and just use my rasps.

The next question is it possible to simplify fitting?  The tenon shootout used machine made mortises,  what means they are already similar and straight. This means that something with the same dimensions as the mortise profile can be used.
- A first tool to help fitting could be using  a profile gauge. This allows to control the profile of the tenon.  A lockable calliper can be used as a profile gauge.
- A second tool should be able to control the alignment of the tenon.  Here a combination square can show if he tenon is in line with the rest of the piece.