Panel Doors - Router or Table Saw?

[Jim Becker]

Ken, I don't glue my panels in. I might pin them center top and bottom to keep them from flapping (some folks use space balls or similar), but no glue. Personal preference. Gluing would also be harder since I partially pre-finish panels before inserting them in the grooves and finalizing the door assembly.

[Bill Hylton]

Ken,

Let me reverse the order of your questions to answer.

Quarter-inch plywood is seldom flat, in my experience, and I doubt there's anything you can do to flatten it. But it won't be a problem if housed in a frame, like a door frame. It's not going to twist the frame.

The frame itself must be flat. If a rail or stile is bowed or twisted, you won't have a flat door.

Door joinery: Cope-and-stick joinery that's used universally for doors is just groove-and-stub-tenon with a profile. The cope of the profile adds a skoche of glue area, but it's primarily end grain to long grain, so it isn't adding much strength to the assembly. The majority of doors constructed with such joinery have solid-wood raised panels, which aren't glued to the frame and which expand and contract seasonally. So the upshot would be that you should be able to construct a door frame without a profile, join the parts with groove-and-stub tenons, and NOT glue the panel in place.

With the construct you envision, you can increase the groove depth, which would require an increase in tenon length, which would strengthen the joint. Most cope-and-stick bits cut a 3/8"-deep groove. With a groove-and-stub-tenon, you could cut the grooves 1/2" deep.

Not sure why you'd avoid gluing the plywood panel into the frame. Are you concerned about achieving a slip fit for the plywood? The nice thing about doing this on the table saw is that you can adjust the groove width to accommodate the plywood, which invariably is less than 1/4". Even if the plywood is a little loose in the groove, you can glue it.

More important is to have a good fit between the tenons and the groove.

Go ahead and give 'er a try. You can do it!

Bill

[Ken Stevens]

Great advice. Regarding not gluing in the panel---this would permit less precision in achieving a "slip fit" between panel and groove.

Several days away from trying one....

Thanks.

[John Petsche]

Great tips

[Rod Sheridan]

Ken, I don't own a router, however here's the similar approach using a shaper.

http://www.sawmillcreek.org/showthre...96#post2184896

Regards, Rod.