design question

No, that is acceptable as long as your frames are strong. The panels should float and be non load supporting.

Actually about 7/64" thick and not too thin as long as the panel is not needed for strength.

Should I try to get 3/8ths?

I do not think you will find Oak veneer that thickness.

The 1/4" ply will be fine but will net out to be a little less thick that 1/4", so make sure you have your stock before machining your ploughs.

Also, be aware that the face veneer of hardwood plywood comes in many grades and cuts.

I would look for a Flatsawn veneer, rather than the Radial cut that is too often found in home centers. The flatsawn will give you the appearance of solid stock.

You must also decide if the appearance of the inside of your doors is important enough to buy a ply with two high grade faces.

If the doors will be open much of the time you may want to use A/A ply

- that is ply that has two top grade faces. You would not be too bad off with A/1, or even some instances of A/2.

HTH

Tom.

tjwatson1ATcomcastDOTnet (real email)

Why would you object to gluing ply panels into the frame?

tjwatson1ATcomcastDOTnet (real email)

panels should

I don't know, that's why I'm asking the question. I didn't think there would be an objection, but I thought I'd make sure. I didn't want to have to glue up panels of 1/4 thickness, that didn't seem like too much fun!

Thanks for the replies

Not only is there not an objection but, contrary to the previous poster's assertion, there is a positive benefit to gluing a plywood panel into a solid frame. It unifies the assembly and makes it much more capable of resisting deformation - which is the key to strength.

tjwatson1ATcomcastDOTnet (real email)

Actually never mind, I was thinking solid wood panel vs. plywood. Solid wood will expand and contract and needs to float so that it will not pop open a frame joint as it expands or split itself as it contracts. The plywood panel should do fine glued in. Sorry for my confusion.

That's less than 1/8". Are things that bad? Did you mean 7/32"? -- Igor

For non-load bearing, like door panels, you might use 1/4" [but I'd do raised wood panels for that, or at least add some sort of design for appearance.] For load bearing, I'd go to 1/2". Personally though I'd use at least 1/2" all round.

OK, now I'm getting a bit confused. I understand that plywood is dimensionally more stable than hardwood glue ups, but so stable that you could actually glue it right into a frame? i.e. there would be no seasonal movement at all?? IT doesn't need to "float" at all? (Do I sound incredulous?)

Because there's no point to doing it. It _shouldn't_ hurt, from a moisture movement point of view, but equally there's no positive reason to do it. A Mission style piece should be plenty strong enough just on the M&T's of the frame.

Can't agree with that, Andy.

The lateral strength that is introduced to the assembly by the glued in ply is a great benefit.

In a perfect world, all four feet hit the floor with equal force. In the odd instance of the imperfect world, these feet hit with varying force, which works on the frames over time.

The amount of glued area that is introduced to the frame and panel assembly by gluing in the ply panel is tremendous, when compared to the glued area of the joint faces.

As the strength of the assembly is aided by the glued area, giving away the potential strength of the frame to panel glue line would be reprehensible.

tjwatson1ATcomcastDOTnet (real email)

YES... And please disregard EVERYTHING that I have had to say on this thread... Damn...

yup.

tjwatson1ATcomcastDOTnet (real email)

The panels can be 1/4" thick as they don't have much effect on the structural strength. Ply thickness can vary, so you'll have to get the ply before cutting the grooves.

I'm sure nobody will object, but understanding wood movement is very important. Gluing the panels will cause stress with changes in humidity. Stain and finish the panels before assembly.

No.

No.

tjwatson1ATcomcastDOTnet (real email)

Here is where I would disagree with you. At least for the staining, and especially if the panel is _not_ glued. Too many times I have seen cabinet doors in which the panel - whether ply or not - has shifted and it exposes an unfinished area. It would seem that there would be a concern that the dados in the frame be large enough to hold the (thicker) finished panel, but other than that what is the problem - that the glue (which you recommend) won't hold? I agree with you that gluing ply panels can be OK and enhance the door's integrity. But is that essential? To the extent that gluing-in a ply panel is helpful, is it so critical that having finish on some of the surface will substantially lessen the (potential) enhancement?

You may say that a glued-in ply panel _won't_ shift so pre-finishing is not needed. Maybe.

Personally, I do not want any unfinished panel areas to show and so at least staining the panel before assembly seems like a good idea. FWIW. -- Igor

We are talking specifically about a glued in plywood panel.

Not a problem with a glued in panel.

This has been explained elsewhere in the thread.

The glued in panel will not shift. Not maybe. Absolutely.

If you would apply your logic, you might as well prefinish the working faces of your mortise and tenon joinery.

tjwatson1ATcomcastDOTnet (real email)