Back/side panels for a tv cabinet

[Gt4]

I'm wonder if how best to construct panels for the sides and rear of a tv cabinet. I was considering biscuit joining 3 x 150mm wide strips of wood together to form a panel, and then dropping this panel into grooves routed into the aprons.

The problem with this, as far as I can see, is that this wouldn't allow for any movement/expansion of the wood. If didnt use any glue, or even cut tenons onto the end of the panel, then I suppose this would work, assuming I cut the grooves a lot deeper than the panel to give clearance. But this seems like it would result in quite a loose fit. How would people on here recommend doing it? Cheers

 

[custard]

I could spend all day replying, however tea break's nearly done and I've got furniture to make! So the simple answer is you'll need about 1/8" or 3mm for expansion/contraction of the panel on this project.

One useful tip, finish the panel before assembly, if it shrinks after assembly and finishing you'll be left with a "grin", a strip of unfinished wood.

One other thing, if you can possibly avoid it don't biscuit up smaller strips for the panel. Instead edge joint the strips as described here,

how-to-edge-joint-t112936.html

 

[Inspector]

I do as Custard does with one tiny addition.

To make sure the panel stays centred in the frame when I glue it together I drill a small hole in the back of the door through the groove and put a dowel in it. I cut a small notch in the middle of both ends of the panel. When you glue it together the peg and notch centre the panel and seasonal expansion is even with no chance of panel gapping on one side.
Pictured is one I recently did on a large tray to illustrate. The 1/8" dowel hasn't been glued in and trimmed flush at this point.

Pete

 

[Gt4]

Cheers guys that's great info. Just to be clear though, should i be glueing the panel into the aprons or just leaving it loose? The dowel would keep it fairly secure anyway i suppose? Because if I did glue it, it would prevent the wood from expanding. Have i got this right?

 

[custard]

For a solid wood panel it's always loose, never glued.

In fact another benefit of pre-finishing a solid wood panel is that the finish will generally stop any glue squeeze out (from the mortice and tenons in the stiles and rails) from adhering to the panels.

 

[Inspector]

If it is a door no glue.

That picture was actually of a 15” x 38” tray so it got an inch or two of glue in the slot at the dowels and a couple inches in the middle of the long sides. It helps keep the mitered frame from racking. If the panel moves the long sides will either bulge a touch or hourglass a little. Not a problem for the tray but you don’t want that to happen on a door.

Pete

 

[Gt4]

Brilliant. Thanks guys