Replies

1. 
   oldusty | Aug 02, 2008 05:25pm | #1

     Is the plywood domestic or China ply ?

         Imho if it is the China junk take it back for exchange or refund it only warps more after you rip it up , trust me .

         I guess it Is it 3/4" thickness , depending on how warped they are there may be some gain from weighting and blocking them down to the floor and over doing the warp the opposite way .Maybe rip them before trying .

        Will you be ripping the pieces to 24 or 12" to build cabinets out of or how will you use these sheets ? What makes you think they are too warped to use ?

       Typically the plywood gets glued and fastened or screwed down so some warp disappears .

          good luck           dusty

1. 
   tom77 | Aug 02, 2008 10:31pm | #2

   Dusty,Thanks for the reply. This is not cheap Chinese plywood. It should be pretty good stuff at $100 per sheet. I am making two bookcases out of it, and the sides, shelves, and top/bottom need to be reasonably flat. The back panel and face frame will help some, but not enough in my opinion. These two panels were in a very hot warehouse. (It has been running high 90's with very low humidity here recently)Tom.

1. 
   oldusty | Aug 02, 2008 10:41pm | #3

   Tom,

         Glad your not using the other , my point is when you rip the ply up into 11 or 12" pieces for the bookcase parts the warp will decrease as will the force that holds it. The shelves will be the only pieces that are not held flat by another part . My educated guess is when you slice them up the warp will all but go away . Use the crown up on the shelves and with weight they get flatter.

           You never said how bad the warp is , so this is really in general .

             luck to you                  dusty

1. 
   tom77 | Aug 02, 2008 11:12pm | #4

   Dusty,
   I thought about that. The sides are 48" long and the warp is over 1/2" in that length. It is possible that the back panel and face frame would straighten this out, but I am doubtful. If I rip the panels to try them, then I cannot exchange the panels for flat ones next week.I now have both panels sitting on 2x4's with weight in the middle, trying to reverse bend. We will see.Thanks again, Tom.

1. 
   oldusty | Aug 03, 2008 12:46am | #5

        Tom ,

      With a face frame and a back you won't have any problem , you may not find any better . Material is not perfect hardly ever especially plywood products .

    I cut a lot of plywood and the warp you describe would not be construed as a defect or downgraded on flatness . That really is how it is often times ,choose the best place for each panel .I know after you rip it , it will calm down , yell at me if it don't .

            dusty ,who has heard of a flat plywood

2. 
   KeithNewton | Aug 03, 2008 01:26am | #6

   Tom, I am with dusty on this. I think you should be able to straighten it out as you build it. I would put the bow in on the sides, then let the shelves push them out to straight, if the back and whatever the front trim is. And that only matters if the shelves are adjustable. IF they are all fixed, then it really won't matter.