Replies

1. 
   pzaxtl | Sep 03, 2008 05:19am | #1

   Never planed plywood.  Years ago, I edge jointed some to true up a bad TS cut.  Big mistake!  Chipped off veneer facing, tear out on the ends and trashed my jointer blades.  Only made that mistake once.

2. 
   489tad | Sep 03, 2008 05:19am | #2

   jrogerh,

   Buy more 1/2".  If your stuck and need to use the 5/8" cut a 1/16" cheek around the edges to give you the 1/2". 

1. 
   489tad | Sep 03, 2008 05:22am | #3

   1/8" cheek.  sorry about that

3. 
   Jamie_Buxton | Sep 03, 2008 05:54am | #4

   Planing cross-grain gives you a badly torn-up surface.   Also, the interior plies on most plywood are a lower grade than the face veneers -- lots of knots and voids.   So it ain't the best approach.   The other posters offered better ways to do the task.

1. 
   jrogerh | Sep 03, 2008 09:50pm | #7

   To Jamie and all:

    

   Thanks very much for your inputs.  I'm convinced: NO PLANING PLYWOOD. (New acronynm NPP.) 

4. 
   ring | Sep 03, 2008 08:02am | #5

   You're better off just rabbeting the edges to get the thickness you need.

   However, for general info - you can run plywood thru the planer but there are 2 serious downsides. First, as was pointed out, the inner plies are usually full of gaps and defects that you really don't want to see. Second, planing the glue in plywood is devastating to your planer knives. It's a last resort solution only.

   David Ring

   http://www.touchwood.co.il/?id=1&lang=e

1. 
   dkellernc | Sep 03, 2008 03:40pm | #6

   It's also potentially dangerous to plane plywood.  Planers (particularly the "lunchbox" kind) are designed to plane with the grain, period.  If the cut depth is such that the ply that's on the the final surface is cross-grain, there's at least the potential for the plywood to crumble and self-destruct inside the machine, with disastrous results.