Replies

1. 
   ring | Dec 19, 2005 04:09pm | #1

   Probably not.  Depends more than anything on the finish it receives and the use (or misuse) it gets.  Forget the cleat and put your effort into the finish.

   DR

1. 
   Quickstep | Dec 20, 2005 02:09am | #2

   Since it is used as a food prep area, my finish options are fairly limited. I started with a parrafin/mineral oil mix, but that didn't last very long. I'll try walnut oil next, but a really moisture excluding finish like varnish isn't in the cards. To further aggravate matters, there's an oven in one end of the island, so the end grain on that end gets dried out. Am I doomed to be haunted by these cracks forever? 

1. 
   ring | Dec 20, 2005 07:39am | #3

   Perhaps.  All I can propose is to try out a finish, and if it isn't satisfactory move on to another.  In the end you may very well need to settle for partial success.  Or if we're lucky maybe you'll hit on something that could help everyone.  BTW, maybe you can use some kind of insulation to at least partially deflect the oven's radiation.

   DR  

1. 
   Quickstep | Dec 20, 2005 09:40am | #4

   Thanks for sharing your thoughts. One of the biggest worries is having more cracks develop after I joint and re-glue. This thing is heavy and I'm not eager to go through the excercise of ripping, jointing and re-gluing only to have it happen again. I think I'm going to try sealing the end grain with shellac, an maintain the top with walnut oil. Suprisingly, the oven is pretty well insulated. very little heat comes from the top of the oven, but everytime the door opens, all that heat hits the end grain. Maybe my best shot would be to kill power to the oven and encourage use of the microwave instead! If I have some success, I'll post the magical solution.

2. 
   JohnWW | Dec 21, 2005 12:52am | #5

   Assuming that everything else was done properly in stock preparation and glue up, the cracks are developing because the exposed end grain is losing moisture much faster than the wood further in from the ends.  The ends shrink before the rest of the top and the only way to accommodate the difference is for cracks to form on the ends.  The heat from the oven would make the problem worse by causing the moisture to evaporate from the wood much faster than normal.

   Moving the top from what was probably a cooler moister shop into the heat of a kitchen would cause an initial sudden loss of moisture that triggered the cracking.  It is possible that in the future the top wouldn't be under as much stress from ordinary seasonal moisture changes and the cracks won't reappear. 

   There are a few things you can do that may help.  One thing is to seal the end grain so that it doesn't lose moisture as quickly.  Being that you've already got an oil paraffin mix on the top, just apply straight melted paraffin to the ends, kept liquid with the careful use of a heat gun to maximize the absorption of the wax into the wood.  The rest of the top shouldn't be sealed as well, it needs to lose moisture to get down to the same level as the ends of the slab.

   The second thing you can do is drill all the way through the slab, from one edge to the other, an inch or so in from each end and install a crosswise threaded rod with nuts that will compress the end grain and so resist the formation of cracks.  This is easy to do when gluing up the slab, you can drill the cross hole in each piece before assembling the top, drilling a long hole across the top after it is assembled is a difficult job.

   John W.