Step 7 - Dados and Rabbets
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We dive right in this morning with laying out the many dados and rabbets that help the various pieces of the cabinet line up and stay lined up. The plan we use as a starting point for this piece of furniture was made to use plywood and uses butt joints in most places. But I prefer to re-design it to use the fancier joints because they offer many advantages in keeping the parts in proper alignment, not only as it is assembled, but afterward as well. A butt joint is two pieces of wood that butt up against one another. A dado is a shallow groove not on the edge of a piece, and usually across the grain of the wood into which another piece fits. A rabbet is a shallow recess at the edge of a piece that serves to hold an adjacent piece (usually at 90°) in proper alignment.
Now that we know where all the cuts must go, we use a scrap block and a mallet to gently dismantle the frame pieces. Milling the individual pieces is handier and safer than trying to pass large panels through a cutting tool. Everything has been carefully labeled so all the parts will go back together just as they were. This is especially important because I hand fit each joint; tenon A is a perfect fit for mortise A, but will not be so in mortise B.
There are a couple of ways to make a rabbet. (not to be confused with a rabbit) Many people will use a rabbeting bit on a router. But I prefer to use my table saw. Making a wide rabbet -- in this case up to 7/8" wide -- would require multiple passes with a straight bit, and getting the width on that last pass exactly right has always been a headache for me. I prefer to use a good ATBR blade on my table saw. The ATBR blade cuts quickly and leaves a flat bottomed cut. for these 1/8" deep by 7/8" wide rabbets, I can cut them with one pass.
My shop assistant, Dolly, takes a break from patrolling the perimeter with Zadie to stop in and grab a quick nap. The noise from most of the tools doesn't bother her at all -- except for the surface planer, she will leave if I fire that up.
Next we take a few moments to seal the end grain of the filler panels. Why? No one is going to see them, they will be buried in grooves in the rails and stiles. Because, the end grain of these thin panels gives up and absorbs moisture from the air much faster than the faces. If the outer edge of a panel -- or any piece of wood for that matter -- shrinks faster than the middle of that piece, it cracks. So, to prevent the edges from drying out too fast and cracking, I brush a thinned coat of the finish we will be using onto the end grain, which is porous and drinks it in. I apply as much as it will take in, then set the panel aside to dry. Sealing the end grain in this manner prevents that edge from giving up moisture faster than the rest of the panel and causing a split.
While waiting on the panels to dry I use a sharp chisel to touch up the tenons, grooves, dados and rabbets on all of the frame parts, making sure that they will all fit together without problems from fuzzy bits or ridges that may have been left in the milling process.
The rest of our time today is spent applying wood filler to any pits or checks on any of the parts and putting away our toys. In the morning everything will be thoroughly dry. The panels will need to be finish sanded before they are mounted in the framing.
Man Hours: 5
Materials: none
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