Replies

1. 
   johnhardy | Mar 15, 2003 02:25am | #1

   If this board isn't taken out of the sink and dried on both sides it might be absorbing more moisture on the underside than the top side, causing problems like this.

   John

1. 
   wayneskid | Mar 15, 2003 02:37am | #2

   John,

   Thanks for the thought but I don't think that's the issue.  In use, the board rests on the rim of the sink so both sides are exposed to the air.

   WS in AK

1. 
   johnhardy | Mar 15, 2003 02:43am | #3

   While I was on assignment in Houston (batching it) I made the mistake of leaving my cutting board in the sink after cleaning it. The underneath side didn't dry as fast as the top and it started to warp. If your board covers a large portion of the center sink it may not be getting enough air flowto dry as thoroughly as the top. But this is just a guess, and without seeing the sink and board I really can't tell if this is "it" or a red herring.

   One way to tell would be for them to use the board, after a fixup, and to remove it from the sink after use, dry it well, and place it where residual moisture will evaporate evenly. If, after the same number of months, the problem doesn't recur you'll know what the problem was.

   John

2. 
   UncleDunc | Mar 15, 2003 03:23am | #4

   I suspect the main problem is the choice of woods. Maple swells and shrinks quite a lot more than mahogany with changes is moisture content.

   
   

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   Edited 3/14/2003 8:24:30 PM ET by Uncle Dunc

3. 
   Splintie | Mar 15, 2003 06:19am | #5

   Combo of all three things: the thickness of the board is exaggerating the difference in expansion coefficients of the various woods, which is manifesting itself bec of the role played by that excess moisture on the bottom side. And the more it expands, the tighter it fits the sink, the more moisture it holds in the sink...

1. 
   wayneskid | Mar 17, 2003 03:54am | #6

   What you are sugesting  re. trapping moisture in the sink is not my problem.  The board covers less than half of the small sink opening and is seated on the rim of the sink several inches above the bottom of the sink.  It is not sitting on the bottom of the sink and does not close off the sink opening so as to trap moisture.

   Your other point has merit though.  Which leads me to the next question.  Other than to use only one kind of wood in the glueup, what is the reccomendation?  What woods would have similar moisture absorbtion characteristics and provide for interesting color contrast for a cutting board?

   Is there a definitive reference book on making cutting boards?

   ws

1. 
   UncleDunc | Mar 17, 2003 04:43am | #7

   Here's a source for the shrinkage characteristics. Bruce Hoadley's book Understanding Wood has an extensive discussion of shrinkage and stability.

   http://www.woodbin.com/ref/wood/shrink_table.htm

2. 
   Splintie | Mar 17, 2003 08:12am | #8

   I make lots o' cutting boards, and i can guarantee you that the air below the cutting board is moister than the air above. There is a sink trap evaporating a few inches from the board underside. Not as much if the board doesn't cover the sink, but still.

   I use all kinds of domestic and exotic woods, but they are all kiln-dried wood, which moves less than air-dried wood, another factor to consider. I also make them just 3/4" thick unless it's a special order thicker one, so if the wood varies a bit, it won't be as obvious in a thinner board. FWIW, i use poly glue for my boards so as not to introduce a lot of water into the joints.

   I don't know of any "definitive" reference specifically for cutting boards.

1. 
   wayneskid | Mar 17, 2003 07:55pm | #9

   Uncle Dunc, Splintie and everyone else ....... thanks for all your input.  To sum it up, here's where I think I am:

   1) My board is too thick; I think I'll cut it in half and come up with a modified design to keep it positioned on the sink rim.

   2) I need to advise the user to: a) wash and dry after each use. and b) don't keep it in place on the sink.

   Just a couple more questions: What is a good brand of "poly" glue?  Do you think the salad bowl finish I mentioned earler is OK.  I will reccomend adding a coat from time to time.

   Thanks again,

   WS

1. 
   Splintie | Mar 18, 2003 12:41am | #10

   The best value i've found in poly glue is Elmer's brand, sold at Home Depot for about $9.60 a quart. It foams up less than some other glues, and costs less than the brands like Gorilla glue that advertise so much.

   Salad Bowl finish is fine for looks, but all oil finshes will allow moisture to pass freely.