John,
I have glued plywood panels in doors of this construction and had great success. The only movement to affect it is in the length of the rails and that is very minimal. To allow for this I just glued the center area on all four sides.
John,
I have glued plywood panels in doors of this construction and had great success. The only movement to affect it is in the length of the rails and that is very minimal. To allow for this I just glued the center area on all four sides.
Charles M
Freud America, Inc.
Just a note. Using 1/4"ply, use a 7/32" bit.
They make rail and stile bits sized for ply panels.
I've been working with some 3/4" birch veneer ply at HD (I believe Norwood is the mfgr) and by golly it really is 3/4" thick. So when is plywood undersized and when is it not? I just read that last question and realized how much I opened myself to the sort of answer I would supply (when it's 3/4", it's 3/4"...). But you get the idea.
Also--Charles M., why are you not concerned with movement along the width of the rails and styles--shouldn't that be more pronounced than changes in length? Does it have to do with how the rails and stiles are joined/glued?
The rails will expand/contract slightly with the seasons or ambient conditions. I've seen extreme examples where the wood was very dry when assembled, then sat at humid construction site before installation. Every door had rails that were expanded out past the ends of the stiles by at least 1/32".
When I make ply panel doors, I either use 3/8" ply and rabbit the panels to fit the groove, as Charles suggested, or use undersized cutter with 1/4" ply. Then I glue the sides only to let the rails epand inwards as outwards. I use 3/8" ply instead of 1/2" so that the ~1/16" reveal around the rabbit is less obvious, and the assembled door frame can be sanded without fear of going through the veneer.
Having said all that, most shaker doors that I make have a "reverse raised panel of solid wood...
JR
Another argument against using a single 1/4" think panel is that most (but not all) of the 1/4" stuff on the market is A-4 grade, which could make the inside of your doors really ugly. The -4 allows the back side to have voids, bark and other nasties in the face ply.
1/2" ply is usually A-2, which looks decent, or you can do what Larry suggested and laminate two 1/4" pieces.
As to how exactly how thick plywood is going to be, you just have to wait until you get your hands on it to find out. I broke out my brand new Freud under-sized plywood dado bit the other day, only to find out the plywood I had was, in fact, a full 3/4" thick...
--Brad
The change in width of the rails and stiles is definitely more pronounced than the change in the length but the field where the panel is located is not affected by this. This field only changes based on the changes in length of the frame members.Originally Posted by Rob Blaustein
Charles M
Freud America, Inc.
Relative to Charles' drawing, this is somewhat like what I normally do with solid panels, but I use a "Shaker" bit that provides a slight reveal on the back with about a 20 degree "bevel". Here's an example:
Last edited by Jim Becker; 02-23-2006 at 9:53 AM.
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The most expensive tool is the one you buy "cheaply" and often...
Just a minor nit pick, but the rails are moving across the width, so depending where they are fastened to the stiles, this movement will either be outwards, inwards, or both. That's just part of cross-grain construction. Does it matter, probably not, except for unusual circumstances like I described above.Originally Posted by Charles McCracken
I've also seen mitered doors move such that the outside dimensions stay constant, constrained by the outer corner of the miter, while the inside grew slightly larger, with the inside miter joint opening up as the wood dried. Like I said, these may be extremes, and must not be all that important in practice.
JR
I'm guessing I couldn't do that with plywood panels since that reveal would be plywood without its veneer and it wouldn't look so good. So it sounds like if I went with 1/2" ply I would use Charles's approach. I'm leaning towards 1/2" over say 3/8" because I will likely use some 1/2" for other parts and it saves me buying a full sheet of expensive plywood just for a few pieces. I'm also not sure that the place I get me plywood carries 3/8" walnut veneer--I think they have 3/4, 1/2, 1/4.Originally Posted by Jim Becker
This has been a very helpful thread--thanks again to all who have contributed.
JR,
That's a good point but IME with the Shaker door I have found that for 2" wide stock that is grooved then assembled with stub tenons the potential of warping rails is more prevalent than the change in width.
Charles M
Freud America, Inc.
Agree totally. I just wanted to add this to the thread as it's relevant for "Shaker" style doors. The cutter I happen to have for this is from Lee Valley (green and bought long ago), but many of the bit manufacturers have similar available...I'm seeing it more and more in various catalogs. My kitchen cabinets were made this way. Since they are painted (sprayed acrylic), the panels are all made with 1/2" MDF. The little angled reveal is a nice touch when you open the door and leaves more of the panel mass than a "standard" reverse raised panel would.Originally Posted by Rob Blaustein
But that brings up another point...using Charles' picture again as a reference: It is a good idea to size the panel so that you still have a little bit of a gap between the rails/stiles and the panel once the construction is glued when you are using solid stock for your rails and stiles...it accommodates a little wood movement and space balls or the equivalent will keep the panel centered. This is still ok with plywood...just color the rebate before assembly to provide a suitable look. That could be black to emphasize the shadow line or a dye that colors the exposed (non-veneered) areas similar to the veneer on the panel. You must do this before assembly to avoid a lot of angst!
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The most expensive tool is the one you buy "cheaply" and often...
Yes - 2" to 2-1/4" - I agree - no problem.
I tend to do more 3" and even 4" R&S doors, and my most popular miter door style is 3-1/2" frame, so I have to plan for more movement.
JR
I can't answer that specifically, but I am making kitchen cabinet doors exactly in the manner you first suggested, but with maple. 3/4" thick w/ 1/4" plywood panels. I got A2 so it is finished both sides. Per many other's suggestions I chose to glue the panels in for both strength and to prevent rattling. Hopefully it won't create a problem. As for "heft" they seem adequate.Originally Posted by Rob Blaustein
But, the thickness is an issue. I bought an undersized plywood bit (15/64 which is the standard) and found it to be too big. Using a dial caliper I found the ply was actually 11/64 I believe. So I found a Freud 5mm bit at a local dealer and used that with good results. I would advise that you measure what you actually get before running out an buying a bit only to find something else would be better.