Question for the students of wood movement

I resawed some cherry for drawer fronts, applied to plywood boxes. Finished thickness is something between 3/8 and 1/2, two pieces bookmatched to arrive at the 7-3/4 and 10-1/2" widths. I then brad-nailed these to the plywood boxes from the inside. And I didn't skimp on the brads. :( Couple days later, three or four of the nine fronts have opened at the glueline (plastic resin). I'm not a student of wood movement...but I wouldn't have expected a problem with this...and I assume that's exactly what I have. Is it the brads that did me in? :confused:

For what it's worth, the wood had sat around the shop for a couple weeks, resawed beautifully, sat and stayed perfectly flat for two days before I glued them together, looked wonderful after the drum sander, and looked fine yesterday when I went brad happy. :eek:

This is more irritating (and embarassing!) than anything else, because the drawers are for a built-in dresser and nobody will ever see them but LOML...but I'd rather not repeat the boo-boo if I can help it.

BTW, I'll prolly never find any more cherry as nice as this...and it'll be hidden in a dark corner of the bedroom. :(

Many thanks...it's been a long time since I worked with 'real' wood. :D

KC

KC, my first reaction was this is not an issue of how you fastened it(though I would be a little gun shy of glueing something of that thickness flat). I sounds more like an issue with the cherry moveing after being resawn. When you reswn wood it can spring around on you...sometimes it does this occurs directly after being cut...sometimes it takes a little time for it to occur. It all revolves around the mositure content vs the realative humidity of your shop.

On the other hand, if you applied to much glue it could have restricted any wood movement.....

Sounds to me like you may have had a problem with the glue or the way that it was applied. Most modern glues are stonger than the wood. Since your problems happened at the glue line, I would look at that first.

If I remember correctly, veneer on plywood should be no thicker than around 3/32". If you want the faces to be thicker, they should be glued to the same species of wood as the face, as they will then move together. Otherwise, the cherry will move and the plywood won't, which is what most likely caused the problem. I guess really thin veneer can't muster up enough force to cause a problem. This is just "book knowledge", so hopefully one with more practical experience will chime in.

Dan

I would chalk it up to wood movement. That, and the fact htat the air got to the front, but not the back. My suggestion, and you should know that I don't build in this fashion so am mostly guessing, would be to finish the drawerheads, both sides, prior to installation, and then to use the short screws that have coarse threads and a washer-like head that are made for this task, leaving all but the centered screws in a larger hole to permit a bit of movement.

I'm with Alan...there was a moisture imbalance after resawing. Normally a few brads wouldn't hold things hard enough to matter, but a LOT of them would exert more force than you might first think. (I generally use two screws to mount drawer fronts and the holes in the drawer box are "generous" relative to the fastener) Dan is correct relative to glued assembly, but I don't think you used glue based on your description.

Kirk,
You refered to "working with real wood". Have you not had to worry about this with Mesquite? BTW - I vote for moisture imbalance as well as glue line failure. Did it break the glue line clean?

Quote:

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Originally Posted by Martin Lutz

Kirk,
You refered to "working with real wood". Have you not had to worry about this with Mesquite? BTW - I vote for moisture imbalance as well as glue line failure. Did it break the glue line clean?

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Martin, mesquite is a very stable wood with little or no movement after drying.