I was given a Martha Washington sewing cabinet to repair. it has a 1/2 circle shaped bin on each side with 3 slats missing on one side. Research suggests it was made in the 1920’s or ’30’s, probably from mahogany. It has an unfamiliar joint joining the sides at the necessary angle to form the 1/2 circle.
any idea what this joint is called and how it was made?
Thanks,
Dave
Replies
Not sure of the name, but I learned something similar from a boatbuilder and have used it to make cylinders. He was using it to make lightweight hollow spars for sailboats. His version used all straight cuts, and all of the inside corners were 90 degrees. The angle they were cut at was based on the math of how many staves were being used in the spar. He made oval profiles by varying the lengths of the staves and even tapered them. I have samples in the shop, I'll post a photo later today.
Wound up stopping in the shop this morning... The photo has 12-section and 8-section tubes. More sections let you use thinner material to get to round after planing off the high points. Turns out it is called a Bird's Mouth joint. The one on your sewing cabinet is a fancier one done with matched moulding planes by the look of it.
Here's something from the boat side:
https://www.woodenboat.com/whiskey_plank/hollow-wooden-masts
Thanks. Have seen the bird's mouth joint in the past but didn't make the connection. Biggest issue is that the sides are 2 different widths, & it's a 14 sided oval rather than a circle. I thought the joint might have been made with molding planes, not sure that a router could do the bevel and the round at the same time
Hey,
I've seen the bits for your project on MLCS's website. I've never used them but maybe they'll help.
Mikaol
You might get away with rule joint bits if you can work out a way to feed your stock into them at the proper angle.
The round & cove "canoe" bits on MLCS are too big. Smallest is 1/4". This stock is only about 5/16" thick. That style of bit could be used if the round was about 3/16" leaving a small shoulder if cut in the center of the stock, then cut the stock to the appropriate angle when fitting together.
Wonder how the new pieces would last if I just butt glued them together. It is long grain after all.
That was my thought. Long grain is going to be plenty strong. I would think a lot of these oddball joints were done to move things along in a production setting, which is of little concern to most of us.
That is an interesting twist on the bird's mouth. If the joint is not a focal point or a period indicator of the piece I would do what makes sense to you. A bird's mouth would certainly up your glue surface area if the joints experience any stress.
This forum post is now archived. Commenting has been disabled