Replies

1. 
   bduffin104 | May 20, 2010 04:49pm | #1

   clue:"picture frame surround"

   NZer,

   The solid oak top is probably trying to shrink in width across the grain due to the conditions you've described. I suspect that the two ends of the "picture frame" that run perpendicular to the top are permanently attached and are interfering with the natural inclination for the top to expand and contract due to humidity changes. You would probably have to remove the perpendicular pieces and attach them in a "floating" manner where the top is aloud to move freely.

   This is just an educated guess on my part. Photos of your problem would greatly aid in finding the proper solution.  

   Bret

2. 
   JerryW | May 20, 2010 06:05pm | #2

   I have found this a relatively common problem, especially in the northeast US in the winter when air is dry. I always stand panels and tops up against something so that there is free air flow around the panel.  As to a solution to your current panel, I would turn it over and expose the other side to air and wait - it may correct itself, if it is a simple issue of moisture differential.   It can also be caused by gluing all boards in the same grain orientation (as they were sawn off the log) - you may be getting some cupping in each board causing the top to generally cup.  I was always taught to flip alternate boards to avoid this.  I also was taught to neve rglue up boards wider tha 4-6 in., although I often vilate this.   Sometimes this causes you to not get the best grain pattern, but things stay more flat.

   Jerry

3. 
   SteveSchoene | May 20, 2010 06:13pm | #3

   I think Bret's on the right track

   The picture frame surround is a likely problem.  Unless the center is a separate panel that can expand and contract with changes in humidity, surrounding a solid wood panel with a solid wood frame is doomed to fail. 

   It may be that, in the short term, the failure was generated by not stickering the top, so air could flow around it on both sides as the humidity changed.  That could also have delayed the problem from occurring, but I suspect you should be glad that this has occurred, now with the piece in the shop, being worked on rather than having to account for the destruction of the top after giving it to your daughter. 

   By the way, I always prefer to do the base first, so that the top can be firmly fastened to the base (allowing for wood movement) as soon as it is completed.  In addition, I tend to not alternate grain, that just gives you a wash board.  But with the growth rings all oriented the same way, the attachment to the table rails can pretty easily tame that sort of tendency to cup.   Orienting the boards for the best appearance is probably the best advise, however. 

4. 
   fussy | May 20, 2010 11:53pm | #4

   Nzer,

   Before you cut the top up, flip it over and wait.  It should straighten out.  Once it does, stand it on end until you're ready to finish and attach it.  Don't dispare; I think you'll be fine.  Could the magnetic field in your hemisphere be reversed from ours and be causing this?

   Steve

1. 
   nzer | May 21, 2010 04:21am | #5

   Magnetic disturbances?

   Thanks for your advice ( I really like the look of the picture framed top although I know I'm inviting trouble) so  I have flipped it and will wait for nature and southern hemispheric vibes to set it right!  Cheers, Richard.

1. 
   JerryW | May 21, 2010 07:37am | #6

   I have seen on the internet - must be true - that on the really nice NZ beaches, near barbies, that the clocks actually run in reverse.   Same magnetic disturbance????

   Jerry

5. 
   Jfrostjr | May 21, 2010 10:30am | #7

   Sticker and wait. Do not cover.

   Frosty

6. 
   user-64052 | May 21, 2010 05:03pm | #8

   that is quite large for a framed panel.   the larger the panel, the more space that you have allocate for movement. try washing the concave side with methyl hydrates or alchol and see if that starts to pull it back. it contains some water and whem applied absorbs into the wood(water is minimal) and  the alcohol flashes off quite quickly. I remember once after seal tyhe bottom of a top with shellac that the whole thing went like a dogs hind leg and  this was a months woork that  was going down the drain. I turned it over and took almost a gallon of methyl hydrates and washed it down and within 10 minutes it was all level again. methyl haydrates will not change any thing and flashes off quickly.

   just a straight nice desk top looks good.  the frame and panel on the top seres you no purpose what so ever with a solid  except for collecting crap in the opening all of the way around

   ron

7. 
   nzer | May 21, 2010 08:23pm | #9

   Clocks?  What are they?  The water goes down the plugole in a reverse spiral to the northern hemisphere which may explain the space/time continuum situation.  Desktops warp nicely too!

8. 
   nzer | May 21, 2010 08:28pm | #10

   Mea culpa.

   Thanks for your advice, regrettably I will give up on picture-framing in future. Given that the top is already made I will box on and hope most of the bowing goes away.

   I really appreciate the help from everyone, such an excellent community. Cheers, Richard.