On Wed, 26 May 2004 01:17:53 -0700, charlie b
wrote:

a very interesting joint today. Chinese/Japanese in origin, it is
used to join wood end to end,

In English timber-framing practice, this is an edge-halved scarf
joint.

It's typically regarded as mid-14th to mid-16th century work. Before
this a splayed scarf joint was used, afterwards a face-halved scarf
joint. All three are widely seen and are a valuable means of dating
old timber-framed buildings.

For the splayed scarf, (the mating faces are sloped, and in two
parallel planes. It's locked by a rectangular peg (or pair of wedges)
knocked into the gap between the two steps in the sloped faces.
They're hard to lay out. and take a while to cut because it's a
sloped-grain surface. After the Black Death had killed 1/4 of the
population, there was need for a simpler joint that the surviving
carpenters could have cut by unskilled labourers.

The face-halved scarf is even simpler to cut. Imagine turning the
large flat surface by 1/4 turn, relative to those stopped mortices.
Now the whole thing can be marked on a single face and sawn out
without chiselling into a stopped corner. The face-halved joint is
much less strong (it's still strong, but only in one direction) but it
can be made by even less skilled carpenter's labourers.

A couple of weeks ago I was at Cressing Temple barns in Essex. These
are a pair of 13th century timber framed barns and show both styles of
halved scarf joint. Pretty long timbers too - some are over 40' in one
piece.

--
Smert' spamionam