Wednesday, April 02, 2008

Arches, Neck Moulding, and Keystones

Today I missed the U.S. Concepts arch moulder we had at the place I worked before going out on my own. With that machine I could have churned out the radius casings for the arches on this project in a matter of minutes. As it was, I built them up from three separate elements which are being glued together in the shot below. You can get a sense of the nice morning light in the shop from this photo.



I was curious to see how the mouldings would work together in the real world--I'd seen them in my drawings--so I used some double-sided tape to hold things in place in order to have a look. To my eye, the way the radius moulding wraps around and forms the neck moulding on the pilaster seems ever-so-slightly odd, but the research I've done confirms that this is the way to go. I don't remember it looking strange in person, and I kind of think I'm seeing it that way now because there is such low contrast in this photo between the pilaster's capital and the wood behind it.



I also made the keystones this afternoon. The photo below shows one taped together--sometimes I like to do that before committing myself with glue and clamps. I'd been through several designs of the keystone, and finally found some very helpful guidance in Asher Benjamin's 1830 volume The Architect, Or Practical House Carpenter. Benjamin suggests that blocks of this design be divided into 9 parts, with the center section representing 5 units to 2 units for each of the outer sections.



Dover Publications prints a nice paperback edition of Benjamin's book (ISBN:0486258025) which is available for around $10 at just about any online book seller.

1 comment:

neil said...

Tim:

That Asher Benjamin reference is excellent. It was his text that made me see the grecian oval and roman circle and why cost vary so in moulding shapes, just and excellent book to have in the woodworking library.

Nice work - Nice mention