Sunday, July 31, 2011

Dry Heat, Monsoon Humidity, and tales of Cupping

     Before I get into the technical stuff, I put the first coat of Watco oil on the hanging shelf this afternoon so let me show that first:

This Cumala  is a different type of wood.  Billed as an alternative to Mahogany it has some of the characteristics and coloration but doesn't really work the same.  Quite a bit softer which requires very sharp tools to cut cleanly, it's also somewhat punky.  I selected this piece because of the coloration which I think is probably a mold, disease, fungus by the way it smelled when it was cut.  It does add interest to the piece -- you know me, it's all about the wood!  The drawer sides are  some wood I had left from another project, the Cumala I had set aside to use for the drawers was just too unstable.
     In an earlier post I had mentioned a cupping problem.  I was taken by the figure and color of this board when I should of been checking the end to see which part of the tree this particular board came from.  When I bought it the weatherman was saying that we had 1% humidity and it may have gone up to our normal 6-8% while I was preparing the stock.  Well, a day or so after cutting the dado and beginning work on the dovetails we had a monsoon move in and boy, did the bottom and shelf section cup.  The outside edges turned upward so I was hoping that when the dovetails were assembled it would be enough to keep things in place.  Here's a fairly good shot of how it looks:

This is when I was planing the dovetails level with the sides, look close at the end grain of the pins, maybe you can make out the grain.  It's kind of like a smile!  The ends are tight but the middle has some gapping.  You know what though?  I wouldn't be at all surprised to see them flush up once the weather dries out again.  Yesterday I fit the drawer front for a good fit.  Then today it's been raining (high humidity) and I also oiled it (more moisture) and guess what happens next?  The boy from next door likes to come over so I had just finished the oiling and he asked how it looks with the drawer -- it has expanded enough to where it was tough putting it in!  I learned a lesson when we first lived in Boulder City.  During the monsoon season we couldn't hardly get out of the front door because it would swell up and bind.  Being the woodworker I am, I took it off, planed the edge and it worked just great.  Yeah, until the summer hit again and then we had a good 1/4" of space.

 One last thing about the cabinet.  Usually when you cut a dovetailed drawer you need to put in stopped dados for the bottom and plan carefully to the dado doesn't exit in the tail.  Using this router bit eliminates that chore and will make it much easier for the class.
Glad to have this almost complete so I can go on to another project.

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