Plywood in frame/panel doors, wood movement?

[Eric DeSilva]

I was going to build my first set of frame and panel doors for a storage cabinet in the shop, and was just planning on using plywood for the panels. If that is the case, do I need to worry about using space balls or the like--are those only for solid panels? Seems to me that the issue those accommodate is wood movement from the panels, and plywood shouldn't have that problem. To the extent there is movement with the frame, the frame has to move outward from the panel.

Am I overthinking this? I was still planning on leaving them unglued, but do I have to go the extra step?

[Chris Padilla]

Eric,

I agree that you need not worry about wood movement with plywood panels. I would worry that the panel might rattle within the frame unless you've got it good and snug but over time, it could end up rattling. The space balls will keep things nice and snug for you so I'd still use them.

A trick you can use instead of spaceballs is plain, cheap silicone: just lay several lines on on a piece of wax paper, let it dry, peel it up, cut it, stuff it in the groove. QED!

[john bateman]

I have built them without any sort of cushion such as the space balls, and it worked out fine. I find the balls make it difficult to assemble, come glue-up time. It is important to dimension the panels accurately for the space they will be filling. Even more important is to be sure the cutters give the correct slot for the plywood you'll be using.

The 1/4" mahogany ply I last used was .200" thick, and most of the bits available were for .22". I did eventually find the correct size, but it wasn't very common.

[Jamie Buxton]

If you're using plywood for the panels, glue it in. Plywood does not change dimensions with humidity. Gluing it in does two good things. First, it assures no rattles. Second, the plywood acts as great big gussets on the corner joinery.

[Curt Harms]

I have some plywood doors that when it came assembly time, I put 4" or so of masking tape on either side of the panel groove and put a small bead of silicone in the groovy. My thinking is that the silicone functions sort of like glue but with some flexibility if needed. Don't put too much silicone in so it doesn't squeeze out and the masking tape keeps the silicone off the unfinished rails & stiles. So far so good.

HTH

Curt

[Frank Drew]

Plywood is the norm in commercial work (kitchen cabinets and the like.)

[Eric DeSilva]

Thanks for all the responses... I'm kind of leaning to the hybrid approach at this point... putting a little silicone in the groove during glue up. Should be pretty tight as a fit, since the bit is sized for undersized plywood. Thanks!

[Howard Acheson]

>> I was still planning on leaving them unglued, but do I have to go the extra step?

Leave them unglued. You do not need to worry about movement clearance.

However, my preference is to glue in plywood panels. It makes for a much more rigid, stable and stronger door.

[Brian W Evans]

I've heard and read many times that spaceballs can bleed into the panels. I haven't ever used them, but I've seen pictures of the staining they can leave. I think this is similar to the problem in a recent thread about clamps leaving some residue on cherry.

[glenn bradley]

I glue my plywood panels in.

[Shawn Honeychurch]

A trick you can use instead of spaceballs is plain, cheap silicone: just lay several lines on on a piece of wax paper, let it dry, peel it up, cut it, stuff it in the groove. QED!

Pure Genius. :)

Thanks
Shawn

[Chris Padilla]

Pure Genius. :)

Thanks
Shawn

Well, I'm pretty sure I heard it from a real genius...I just happen to have enough marbles rolling 'round up there to have caught the idea and even more important, able to recall it! :p

[Peter Quinn]

I glue in the panels too. MDF or plywood gets glued in here. Very solid, no rattle. I glue in MDF raised panels with a little epoxy in the grooves to give time for adjustment but wouldn't use more than PVA for flat panels.