Replies

1. 
   tufenhundel | Dec 31, 2003 01:14pm | #1

   There are several factors involved here--depth of box, type of solid wood, type of cut, etc.  The joinery is inconsequential, i.e., they will all be affected by movement the same way.

   What you're proposing is like a mortise and tenon joint (movement wise).  I think I've seen as much as 3.5" long tenons.  So I wouldn't have boxes deeper than this.  If you do go deeper, just don't apply glue beyond this length...but this will get you only so far...

   I am sure you have a reason for not attaching the solid wood front to the plywood front, inset drawers can still be done like this, but this may be your only way.

1. 
   BG | Dec 31, 2003 03:07pm | #2

   pdaquino,

   To pick up further on Tufen's comments, the size and intended use of the draw is important....should dictate or at least direct the joinery of the draw sides.

   With a fitted draw front, half blind dovetails look great but kinda overkill on a 3" deep draw.  Also, with plywood there can be a lot of tearout...doing by hand helps..but there still may be some tearout. I've used a rabbit joint and pins in sides using dowels.  Sliding dovetails only work for me on a draw front that will overlap the face frame....fitted front means the draw would have to be significantly smaller...

   I've made plywood (and solid wood) draw boxes and applied the solid wood flush front...using thru dovetails on the draw box....it looked a bit clunky.  I've toyed with the idea of recessing the plywood draw into the front face by removing some wood from the back of the draw front....have not tried it ...

2. 
   JohnWW | Dec 31, 2003 06:18pm | #3

   The basic problem you have to deal with is that the solid wood drawer faces will expand and contract with changes in humidity but the plywood drawer sides won't. 

   If the drawer faces are narrow, up to perhaps four inches wide, the give of the joints and wood will probably handle the stresses involved.  With wider faces you need a design that allows the drawer face to move to prevent either cracking the face and/or breaking the joints.

   My own first choice in this situation would probably be to use a sliding dovetail for the joinery but this requires a fair amount of expertise and a bit of engineering to work properly. 

   There are several other ways to work around the problem, which you choose will depend on the style of the piece and your skill and tooling, there is no one right answer.

   John W.

    

1. 
   TnSawdust | Dec 29, 2005 03:01pm | #8

   All this talk about differential expansion of wood as a reason to avoid joining dissimilar materials seems to overlook a very basic fact:  Kiln-dried solid wood hardly moves at all in the direction of the grain.  Expansion due to changes in humidity and temperature are practically limited to cross-grain movement for solid wood materials.

   I often glue plywood and MDF bottoms to their solid wood sides/fronts--especially when the drawer is very wide and expected to hold a lot of weight (pantry units come to mind).  This gives the drawers added rigidity and strength which allows use of thinner offsets and shallower grooves than I'd otherwise feel comfortable using.  So far I've had no problems with units made like this and my products have been exposed to a wide range of environments ranging from kitchens to unheated garages & workshops.  And yes, humidity:  East Tennessee has lots of that.

   I'd like to hear from anyone who has actually seen problems with glueing of plywood and/or MDF drawer bottoms to solid wood sides & fronts.  I'm certain I don't have all the right answers but sometimes experience shows that neither do the experts who more often than not just repeat what they were taught--not what they've experienced.

   Al

1. 
   SteveSchoene | Dec 29, 2005 07:47pm | #9

   I wouldn't expect problems gluing in a plywood bottom to solid sides, front and back.  But the question being asked called for joining plywood sides to solid wood fronts.  That's a cross grain situation, hence the need for a good mechanical joint, taking account of the potential movement for deep drawers where the differential movement is the most. 

2. 
   HowardAcheson | Dec 29, 2005 08:06pm | #10

   >> I'd like to hear from anyone who has actually seen problems with glueing of plywood and/or MDF drawer bottoms to solid wood sides & fronts but that was not the question as I read it. 

   The question had to do with the cross grain situation created by gluing plywood or composition material drawer sides to the solid wood front panel.  That does create a cross grain situation where the expansion/contraction of the solid wood front panel is constricted by the composition cross grain joint.

   For front panels up to maybe 4", and a PVA adhesive, you would probably be OK.  For wider drawer fronts, you may run into a problem if there is a significant seasonal change in relative humidity.

    Howie.........

3. 
   CharlieP | Jan 01, 2004 03:07am | #4

   I have often joined solid wood drawer fronts to baltic birch sides.   I primarily use half blind dovetails.  I have been doing it longer than I understood wood movement, and haven't had a problem (yet), perhaps because of the play in the individual tails. 

   Cutting dovetails in plywood without a lot of tear-out is hard.  One thing that helps is to use vertical grain on the drawer sides, rather than the traditional horizontal grain that you would use with conventional wood.  Another suggestion that I haven't tried is to put the first coat of finish (lacquer) on the baltic birch before cutting, to stiffen the fibers.

   A sliding dovetail would likely be smarter, with glue only at the bottom so that the drawer front could expand and contract .  The weak point would be the plywood itself as it comes to the wide point of the tail, but in thin wood veneers. 

4. 
   Telemike | Jan 02, 2004 08:26am | #5

   I really like using baltic birch for drawers. However, I will admit to a really sloppy practice. I make the entire box out of baltic birch with through dovetails (machine made or scroll saw cut) and screw on a showy face carefully aligned with the drawer mounted on slides in the cabinet. I drill the screw holes oversize in the drawer box front to give me some wiggle room, then put the face on, align it, and tighten. I finish it off with some brads to pin the alignment. It comes out great with solid drawers and the drawer front is nicely centered. But, somehow it seems to be a lesser art than traditional half blind dovetails and a carefully fitted drawer.

   I'm trying to learn to hand cut half blind dovetails and perhaps I'll go the honest route next time.

1. 
   eddiefromAustralia | Jan 02, 2004 09:50am | #6

   Here's pretty well how I was trained to hand cut dovetails.  Main difference was not to overcut the tail sockets:

   http://www.popularwoodworking.com/features/fea12.html

   Cheers,

   eddie

2. 
   BG | Jan 02, 2004 02:59pm | #7

   Telemiketoo,

   I think the only thing attractive about using baltic birch ply for draws is the thickness of the draw sides...either 3/8" or 1/2".  Personally, I like to resaw full 1" thick stock on the TS...poplar, oak, maple or even pine and run the cut pieces through the planer.  That provides a nice thickness and a smooth surface for planing and finishing.  Just a thought...