Some time back i built a new desk for my basement "office" out of red oak. I'm not building a printer stand/file cabinet to match it, also of red oak. To use up all the red oak i have I made solid panels for the sides and back of the cabinet; as opposed to buying some plywood (my normal approach). These panels are 22" wide and flat sawn, so I'm expecting s a fair amount of wood movement, I've also never built anything with solid wood panels this wide.  Anyway, I've stained the panels before assembly, but I'm thinking I also want to varnish them...at least with one or 2 coats before i glue everything together (?). My thinking is that if i varnish the panels in place after glue up the varnish will stick them to the rails/stiles of the frame. Is that what will happen? I'll be using an oil based varnish as the final finish.

I think staining and varnishing before assembly will be the best. That way the expansion/contraction will not show any unfinished surfaces around the sides.

Will the panel be loose in the rail and stile frame? I'm thinking it might oughta be. That way the panel can be totally finished, edges and, all. That should decrease any movement within the frame. I like to use Space Balls for these type applications.

https://www.widgetco.com/space-balls?gclid=CjwKCAiA58fvBRAzEiwAQW-hzeXi8oY2cCTG3HNLEICMrAEhxg60US0Tq1Cqsk5xytbBbPSl1xH0jRoC6TMQAvD_BwE

Alternatively, short lengths of window screen spline works, too.

Normally it is floating in the stile and rail with plenty of room to expand and contract (put in  those space balls or equivalent) and please only glue the center of the center most board and only 1/2" long.  On top and bottom  This will act as a anchor point for the wood to move outward from.  Or if floating and grouves all around no need to anchor.  Normally I would cut dadoes in the top and bottom then trap the side along its length (least expansion) with a little gule in the middle to keep it from ratteling.  Then the sides are dry fit dadoes with space balls.

 

It will be floating in the frame. The panel is a little thicker than most (I guess) at 5/8" I've left 3/32" clearance in the dado for the panel to expand (I used a wood expansion calculator for that number). Since the dado is 1/2" deep, I can adjust that fairly easily. It just seems if you finish such construction once it's assembled, the varnish will effectively "glue" he frame to the rails/stiles...hence I'm thinking pre -inishing is the answer.

If you mean you will finish the pieces before you glue it together you sure got to watch and keep the glue area completely clean.

On 12/12/2019 at 8:10 AM, Fred W. Hargis Jr said:

It will be floating in the frame. The panel is a little thicker than most (I guess) at 5/8" I've left 3/32" clearance in the dado for the panel to expand (I used a wood expansion calculator for that number). Since the dado is 1/2" deep, I can adjust that fairly easily. It just seems if you finish such construction once it's assembled, the varnish will effectively "glue" he frame to the rails/stiles...hence I'm thinking pre -inishing is the answer.

Always prefinish the panels.  Then when they expand and contract they will not show a lack of stain/dye.  As for the stile and rail prefinish  but put no finish on the glued surfaces.  Then use a glue color that will complement  or match your color.  That way you have no bridging of finish from Stile and Rail to Panel.  Take care in the corners to not trap glue on the surface of the panel.  Normally I use blue tape and tape off my finish so the glue cannot stick. But when buinding floating panels you need to do an assembly gule up.  So use M & T joints on the Stile and Rail.  Get a firm dry fit (light tap of a hammer to assemble) then do NOT over glue the Tennon into the mortise.  Then drill thru the tennon and mortise and insert a matching peg that you glue in place this mechanically locks the parts together and plenty of glue surface.  It will last for generations.

Edited December 13, 20196 yr by Michael Thuman
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