Floating Panels - Thickness Question

[Tom Grice]

I'm in the process of building the Tall Case clock that Norm built last year on NYW. Thing have been going well so far - but I noticed (too late) that he was using 1/4 inch thick floating panels in the sides of the clock. The panels are roughly 8" * 40" and made of quarter sawn white oak. I mention I noticed it too late because I already built them before I got to thinking about the width and if it would cause problems.

Not to question his-Normness, but I'm wondering if these panels are so thin they will crack over time and if I would be better off going with either a thicker panel or 1/4 inch QSWO plywood (if there is such a beast). I hate to waste good wood, but would rather have the clock stand the test of time.

Any thoughts as to whether I should scrap these panels and go with a different approach? I know QS lumber is more stable, but also know you typically don't want to go this thin with a panel for fear of cracking.

[Jerry Ingraham]

Hi Tom,
I don't see a problem with 1/4" panels, especially quarter sawn panels. I built Norms Nantucket Settle a few years ago and it uses large 1/4" panels which I resawed from cherry and there have been no cracking issues with them. Perhaps someone else will chime in, but I don't think you'll have any problems. Just my two cents worth!

Jerry

[Bob Smalser]

Providing you actually floated them with some wiggle room on the sides, you won't have a problem.

If the panels take up all the groove, or of the grooves are too tight, they can crack.

[Jesse Thornton]

Plywood veneers can sometimes be more likely to show cracks than a solid floating panel for the very reason that they don't float. Being glued to a perpendicular grain, when it shrinks it can't move as a whole the way a floating panel would, so the tension may cause several little cracks in the veneer. If the panel is truly floating (room to move on all sides), made from good stock and has a good finish, I don't think 1/4" is too thin.
Of course, no harm is done in making them thicker (if it doesn't negatively affect the appearance), and if it'll keep you from waking in the middle of the night in a cold sweat, by all means, go for it!;)

[Jim Becker]

I like using 1/4" thick floating panels. In fact, the cherry crotch panels in my current vanity project are made that way. But if you already have thicker ones, just rabbit the edges so that they will fit the groove appropriately and maybe bevel the inside edges if they will show when the clock is open.

[Mike Cutler]

What Bob said. As long as the panels are truly free to float, 1/4" will be fine.
Yes they make QSWO plywood in various thicknesses. It can be expensive depending on the quality.

[Tom Grice]

Thanks everyone! I had the panels already built - but then started having doubts. I can sleep better at night knowing that several people have used panels this thin with good results!

I'm still worried a bit about glue bleeding through the tenon between the rail and stile because the slot for the panel will go through the joint. Worst case scenario - I could accidently glue down all four corners.

Right now, I'm thinking I'm going to be very careful with the glue and hope for the best.

Thanks for the help!

[Tom Grice]

On second thought - I think the M&T is held back far enough from the edge that I will not cut into it when I cut the slot. I shouldn't have any problems with glue possibly bleeding onto the panel then.

Thanks!

[Tim Sproul]

I'm still worried a bit about glue bleeding through the tenon between the rail and stile because the slot for the panel will go through the joint. Worst case scenario - I could accidently glue down all four corners.


For solid frame and panel, I like to wax the end grain of the panels and I chamfer the mortise but only on the walls away from the groove. The 2 combine to make glue squeeze out in the groove minimal and if there is any, the wax prevents a good glue bond between the frame and panel from developing. For waxing, you can simply rub a candle over the end grain a few times.

I pin the panel in the middle of the frame.....which keeps it from rattling when the fit of the panel in the groove gets a little sloppy and keeps the middle of the panel in the middle of the frame, despite seasonal movement. Often, panels are bookmatched or cathedral grain and have a prominent 'centerline' to the grain pattern. Keeping the centerline of the panel in the middle of the frame is, IMO, good workmanship.