How Do I Countersink a Rule Joint Without Leaving a Notch?
Issue: Issue 298
Posted Date: 4/3/2012
I have made several drop-leaf tables, and I am making one now. I can't seem to remember how to countersink the hinges without leaving a visible notch in the table rule joint. Does anybody have any ideas? - Jim DiRenzo
Tim Inman: Not sure about this one. A picture would really help. But, I'm wondering if you might not have the hinge "upside down" in your mind. The barrel of the hinge is usually placed "down" below the surface on a rule joint. Ideally, the hinge pin is at the compass point of the radius of the arcs. I have seen tables hinged with the barrel "up" notched into the joint, though. A rule joint is a working example of geometry. When it is all set and right, the leaf swings right up into place with the profiles of the edges working in a perfect concentric arc together. There are specialty hinges that drop the "cove" edge of the leaf out of sight when the leaf is stowed away in the "down" position. So, one answer is not good for all occasions this time. It never hurts to cut some spare edges on scraps to practice on . . . .
Chris Marshall: Jim, I'm not understanding what notch you're concerned about, either. Are you trying to achieve a tighter gap between the tabletop and the leaf when the leaf is raised? Is it the little fillet above the roundover on the tabletop side of the joint that you wish you didn't have? Is there some sort of offset, or "step" occurring between the tabletop and leaf instead of both surfaces meeting flush on top? Send in a digital photo, and maybe we can take another swing at this to help you further.