Replies

1. 
   Jimurock | Oct 12, 2008 10:20pm | #1

   Maple tops do this quite often, to me at least.  Try sitting it concave side down on a flat surface with stickers underneath to allow air circulation.  With any luck it'll settle down though it may take a week.  A slight cup can be taken care of in screwing the top down to the table.

   This assumes that the wood wasn't wildly unstable, was planed equally on both sides, and so on.

   Jim

2. 
   IdahoDon | Oct 13, 2008 01:40am | #2

   I'd want to determine why it cupped and how much, before saying it's worth messing with.  Has the wood moisture stabilized?  how much is it cupped.  What's the thickness? 

    

   Beer was created so carpenters wouldn't rule the world.

3. 
   philip | Oct 13, 2008 12:55pm | #3

   Saw,
   It is a small narrowish top . These things usually look worse than they are. How much cup? Try turning the top over (so that concave side is down) and using some stickers to stack it so that air can circulate evenly around it for a day or two. If you are in a hurry you cut and rejoin presuming it is made up of more than a single board. Which side is the top-the concave or the convex? If you have not decided which then you could fix it to the frame concave side down and it will be pulled flat .
   But I think it is best to "stack and observe" if you are not in a hurry and have little or no experience of this thing with wood. If the weather is playing around it will be instructive for you to see how wood moves around....

   Philip Marcou
1. 
   SARGEgrinder47 | Oct 13, 2008 05:00pm | #4

   I had a QS oak top cup slightly a few days ago. The stock was around 10% moisture content (AC unit located there) my back shop where the wood rack is until glue-up. I moved it forward for a day or so and the stock went to around 7% as the weather exposure in the shop has been dry with no rain for a month.

   After glue-up it cupped slightly upward in the center. I didn't apply finish as rain was in the fore-cast in a day or so. After the rain.. I cracked the shop door over-night and turned the concave side down on the assembly table. Flat the next morning with around 9% moisture content.

   Added stain Saturday... will begin finish today as it is still flat sitting at around 10% again at this point. So.. it can even happen with QS as weather will play tricks with you. If you can idenify the tricks and take counter-measures which don't always happen instantly... you more than likely get a treat for your effort.

   Sarge..

2. 
   sawzalot | Oct 13, 2008 09:35pm | #5

   I moved the top to another location in the shop and stacked as recommended. The effect has been a decrease in the cupping to the point I don't see there will be a problem. However, a hairline crack has appeared 1 inch from the edge indicating perhaps there was a significant change in moisture content in different locations in my shop.I think SARGE'S comments about having some patience and a good moisture meter is a good recipe for learning how lumber moves inside my shop.

1. 
   SARGEgrinder47 | Oct 13, 2008 10:01pm | #6

   I use a Timber-Check pin style at my hard-wood supplier and keep it in my pick-up.. Then a digital gets the call once at the shop. I do try to buy kiln-dry that is dry and in plenty of time before a project to let it acclimate to the shop as there is a difference in humidity and temperature in my front shop. The front is a two car drive under the house garage (used to be anyway) and the rear is a 1/2 basement with poured concrete walls basically under ground. Poured well I may add as moisture hasn't been even a slight issue in almost 20 years.

   But.. a moisture meter and paying attention to how wood is reacting in your shop.. your local's climate and sudden changes in the weather is a key to long term success from your shop I have found.

   BTW... I would not rule out tension wood but.. if it were extreme you would have noticed it when you ripped it. Some tension wood will react almost violently and some will keep it's secret until after the fact. That to me is what makes this wood game so interesting.

   Good luck...

   Sarge.. 

   Edited 10/13/2008 3:04 pm ET by SARGEgrinder47