Replies

1. 
   BruceS | Jun 25, 2006 04:59am | #1

   Did you check the lumber with a moisture meter ?  But more likely it sounds like it has internal stresses that are being let loose,  Been there many times with the "perfect" looking board.  Ripping off a piece of pretzel is a bummer.  Usually end up on the jointer to flatten the board.

    

   Work Safe,  Count to 10 when your done for the day !!

   Bruce S. 

    

2. 
   Segil | Jun 25, 2006 08:49pm | #2

   Steve10,

        Soft maple is the preferred wood for making high-end upholstered furniture frames because of its resiliency and tendency to maintain its shape once it is dry and stabilized.  Don't fight this wood, let it fully stabilize before machining to final dimension.

3. 
   SteveSchoene | Jun 26, 2006 01:23am | #3

   You didn't mention stickering the boards after machining them.  If they are not fully in equilibrium with your shop having one side flat on a bench can lead to problems. 

1. 
   Steve10 | Jun 27, 2006 04:08am | #12

   Steve:  I had stickered them, but I think it is a combination of moisture and stresses.  Perhaps letting them acclimate for much longer before machining will help.  As I mentioned to Rich, its time to get a moisture meter and stop the guesswork.

   Thanks for your help.

4. 
   Rich14 | Jun 26, 2006 08:01pm | #4

   Steve,

   I agree with Bruce that the situation sounds like the wood has internal stresses, which you've relieved by planing. However, the chance that this is happening is smaller than the probability that your boards simply need to come to equilibrium again with the atmosphere.

   I say that, because the initial milling to 4/4 size should have revealed the internal stress (the boards should not have been flat and true at the milled size).

   You need to let them equilibrate for a few more weeks at the very least. Where do you live? Is the humidity changing a lot?

   If the boards don't return to straight after several weeks, they aren't likely to ever do it, then the only recourse is to carefully cut,  joint and plane them flat and use the (much) thinner and smaller stock that results for another project.

   Rich

1. 
   Steve10 | Jun 27, 2006 04:03am | #11

   Rich:  Thanks for your comments.  I had let the wood equilbtrate but not log enough as your suggestion is several weeks not just days.  This is Georgia and the humidity can make some drastic changes.  Not only that but the hard wood supplier's racks are exposed to the humid air and my basement shop has a/c.  Probably need to invest in a moisture meter and let the wood acclimate and check content before trying to mill it.  Thanks again.

1. 
   Rich14 | Jun 27, 2006 04:32am | #13

   You may also have case hardening, which you won't be able to correct and which is the lumber supplier's fault. He should take the wood back, if that is the case. But unless you are a very big customer, that probably is not going to happen.

5. 
   cscwem | Jun 26, 2006 08:15pm | #5

   sounds like you have a moisture problem to me as well...you might try cutting them to rough length & width (leaving enough material to compensate for any machining you will have to do) before you make them any thinner...sticker them for at least a week after you have cut them...the larger ratio of surfacea area will help the drying process.  you'll be happy for all the thickness you can get when you are trying to flatten them on the jointer...some of the twist might come out as it dries, but you are probably going to have quite a bit of machining to do...

6. 
   BossCrunk | Jun 26, 2006 11:36pm | #6

   It's bowing from end-to-end and in my experience waiting will not help.  That said, it won't hurt to wait if you have something else you can work on. 

   The Maple family has always given me fits.  I love it, but it will try your patience.

7. 
   John_D | Jun 27, 2006 01:04am | #7

   I just resawed a 10" curly maple board, 3/4 stock in half down the middle for matching clock faces.  Strangest thing, I cut it then machine-planed it, then I was sanding it (palm sander) and it started to cup like crazy.  A good 1/8" of cup, right up off the table in the middle.

   I decided to let it settle before deciding what to do.  Next day, I go into the shop and both boards are dead flat again.

   I honestly think it was the vibration of the palm sander I was using, because one face cupped while I was sanding it, and the other face didn't cup until I started sanding that one.  I'm probably wrong, because I've never seen anyone say vibration causes cupping, but I don't know what the heck else caused what I saw.

   Maybe I'll tell the people getting the clocks, not to put 'em on a vibrating surface. :)

   My goal is for my work to outlast me.  Expect my joinery to get simpler as time goes by.
1. 
   Rich14 | Jun 27, 2006 01:21am | #8

   John,

   Could've been heat from the friction of sanding drying out that surface to cause the cupping.

   Rich

1. 
   John_D | Jun 27, 2006 02:22am | #9

   I reckon that's a better theory than mine.  The cup lasted longer than the the board being warm to the touch, but of course the vibration had long since ended as well. :)My goal is for my work to outlast me.  Expect my joinery to get simpler as time goes by.

8. 
   sixty | Jun 27, 2006 02:50am | #10

   the moisture content must be to high.