bowing oak draws

[steamboat]

Hello all. Please can I have your advice
I recently made a chest of draws. For the sides I used reclaimed strips of oak glued together, on the inside I have glued strips of ply as the draw runners and finished the outside with two coats of wax and the inside with one. Unfortunately the sides have started to bow outwards (about 1cm), is this because:
Uneven coats of wax in either side
Glued strips of plywood as the runners
Or other resion.
I have taken the plywood strips off and will replace them with strips of wood screwed on.

Any comments would be very welcome.

All the best

 

[catface]

hello Steamboat,
wood movement like this is usually due to changes in moisture content of the wood (in this case the cabinet sides). If the drawer runners are attached at both ends of the runner, to the cabinet sides, the runner (being long grain) and the cabinet sides (being cross grain orientation) will expand and contract by different amounts when the wood moisture content changes, resulting in bowed cabinet sides (or broken/bowed runners).

The solution is to fix the runner only at the front and allow the rest of the runner to move (float) by using small grooves or slightly oversized holes plus screws & washers to secure the rest of the runner (other than the front ) to the inside of the cabinet. By allowing all but the front of the runner to "float" the difference in movement due to moisture changes can be accommodated, & the sides shouldn't bow. So don't worry, you just need to remount the drawer runners.

Also, the sides should return to flat over time. If you made the piece in a workshop / outside & then brought it into the house, it will go back quickest by returning it to the workshop.

Incidentally, you can encourage warp by using different finishes on each side of a panel, but your problem here seems construction based. When I made my first table top about 20 years ago I did a similar thing, joining the cross pieces direct to the underside of the table top, the moisture content of the wood changed (as it does), and the joints all opened up ! So we all do it.

hope this helps, regards, Catface

 

[newt]

Bit confused is it the sides of the draw that has bowed or the sides of the cabinet. What do you mean by strips of wood.

 

[steamboat]

Thanks very much for the help I have removed the runners and will hope for the best.
Its tricky to know what is best to do unless trained, I suppose it is a steep learning curve, such as life.
All the best