Joint design

[Lee Schierer]

Okay, I'm stumped. How would you suggest I make the joints on the clock case shown in the attached sketch. I don't know if just a straight glue joint will be strong enough. The 90 degree corners aer suited to making finger joints, but what do you do with the obtuse angle joints at the top corners? How do you cut finger joints on an angle. these pieces are 3" wide and 3/8" thick.

I also thought about:

1. A glue block cut to fit inside the corners.
2. Using screws from the outside.

Am I missing an easy, but strong method here?:confused:

[Steve Clardy]

You could make a special angled jig for your miter gauge and do the finger joints. Take a little fussing around to get it done, but would look good.

[Andy Hoyt]

Lee DeRaud posted a box a while back that might get you started.

http://www.sawmillcreek.org/showthread.php?t=31522

Look at Post #8

[Ken Garlock]

Lee, I like your idea of the finger joints.

Consider this: make up a sled for your router table. It would be a 45, 45, 90 triangle. Miter the ends of the flat top and the top end of the two vertical sides. The other top pieces can be a regular 90 degree finger that just lays in the finger you are about to make on the router.

Make sure the sled is a 90 to your router fence. Clamp your 'to be cut' piece to the 45 face of the sled with the bevel down on the table. It will look like a plane blade ready to be shapened. You are ready to cut away. You can make your spacing by using gauge blocks to move the fence back for each cut.

I hope this makes sense. Sound like it will take an hour and you are in business. An hour for me, 20 minutes for you.

[Michael Ballent]

Dave Richards came up with a jig that was very slick to be used with a router to make angled finger joints. http://www.sawmillcreek.org/showthread.php?t=31749 is the thread but his pic is no longer in there :(

[Jim Becker]

If you want to use "clean miters" (of appropriate degrees, of course... ;) ) splines would help make for a strong joint and the clock back would further reinforce it.

[Barry O'Mahony]

I agree with Jim, splined miters would be the easiest.

[Jon Farley]

I just did a similar project with some odd-angled mitres and I used splines. They are simple to do and work great. I'd post pics but our digital camera has been MIA for the last few weeks.

I should add too that I think splines would be stronger than any complicated box joint

[tod evans]

lee, i`d miter all the joints and rub glueblocks on the inside using hide glue...02 tod

[Larry Reimer]

Lee, in an old clock case I would expect to see glue blocks holding that joint. Don't think I've seen a clock case of that design with finger joints or dovetails or some such joint, they almost always went for the clean close miter joint look. Since your case is 3/8" thick I'd think that would be a bit thin for a spline, but I'd be tempted to try it anyway just to see if I could get around the glue blocks.

[Cliff Rohrabacher]

My two cents:
It depends on the look you want. You cpuld go with a more ornate modern look and expose your joinery using dovetails, regular or assymetrical, inlaid dovetails, or fingerjoints or inlaid fingers. Hell you can even mix it all up. There are other very sophisticated interlocking joint patterns that don't require any jugs but you will need a drill press.

Or you can go more traditional as is your outline and miter everything with internal splines for added strength and use hide glue to lay glue blocks in (hide is somewhat better than poly glues in hand placed glue blocks).