Replies

1. 
   notDusty | Oct 11, 2005 12:49am | #1

      Hi Larry ,

                            I don't mean to sound negative , but ,  try and find another board . It is what it is and may always be . You could try and plane or sand off enough material to make the piece flat , but it may be too thin for your shelf when you are done . Others may tell you differently but in my experience once a piece is cupped , unless it is fastened or in a frame it will stay cupped . Perhaps you could try putting some bread board type ends on to flatten it out , it just depends on how much time and effort you are willing to put out  for one shelf .

                    good   luck       dusty

1. 
   dwyer | Oct 11, 2005 02:10am | #2

   Larry;
   Cut the board into 2 or 3 pieces. Mark each cut so that each piece can be reassembled as they were cut. Flatten each piece on the jointer and square the cut sides and then reglue the pieces back together just as they were originally. If you don't remove too much material you will not be able to see the cuts without a very close eye. I have done this a time or two and it works very well. Good luck

1. 
   philip | Oct 11, 2005 10:47am | #6

   Exactly. Spot on.A meeting of the minds. Times are definitely achanging. I can remember merely hinting at this perfectly acceptable practice and there was a cyber lynching-well almost.I lived to fight another day, safe in the knowledge that the accuser was perhaps a little shy of glueing boards :-)Philip Marcou

1. 
   LarryMartin | Oct 11, 2005 10:30pm | #7

   I chose to use a different board to avoid the problem altogether. Just to see how it would work out, I ripped the board into three pieces, thickness-planed each and glued 'em back and it worked out quite nicely.Thanks for the suggestions, all

2. 
   WayneL5 | Oct 11, 2005 03:17am | #3

   Dwyer has the best suggestion.  Wetting the board is temporary.  Once it dries completely it will return to its cupped shape.

1. 
   ClevelandEd | Oct 11, 2005 03:37am | #4

   The cupping is a response to the wood, to its structural pattern.   You can't change that tendency.

3. 
   Telemike | Oct 11, 2005 05:06am | #5

   If the moisture content of the board is uneven, it can cup and you can take the cup out and use it. Actions as simple as leaving a a board face down on a surface can warp it if its water content is different than the equilibirum water content. Also, finishing the faces of a board differently such as putting more coats of finish on one side of boards or rubbing out and waxing only one side will cause the board to warp as the finished side reacts differently than the less finished side (unless the boards are at moisture equilibrium with the shop.)

   If this isn't the case, I'd not use a cupped board whole because it will continue to cup as the indoor humidity changes between wet summers and dry winters. If you cut the board, you should flip every other stave but this destroys the grain continuity. If you live in an area with relatively constant interior relative humidity like Sacramento and Los Angeles, the change is not bad because the summer himidity is very low and the winter humidity is offset by heating (which lowers the relative humidity). In most places, even the best furniture is stressed by the expansion and Shrinkage.

   I think that choosing wood and selecting wood for specific purposes in a piece is the foundation of lasting woodwork and every time I've cut corners (too often, I'm sad to admit), the work has developed cracks, gaps, or drawers and doors didn't fit quite right anymore. Hey FWW, how about some more articles on choosing boards and laying out parts on those boards? Not really sexy stuff, but fundemental and not trivial.

   
   

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   Edited 10/10/2005 10:22 pm ET by Telemike