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Mitered half lap? It's not so tough! If you have
a router and can read a rule, then your all set!
I'm making a pair of L shaped pieces to form a shelf.
The picture at left is half the joint. Where this is 3/4" stock, I made
the depth of cut a whisker under 3/8". I Know I'm going to need to tweak
this joint to make it fit right, I'd rather remove stock than shim the
joint. First, layout the 45 degree layout line
on the top of the longer board. Clamping will be easier later on when we
assemble the joint.
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Chuck a
1/2" straight cutting bit in your router and measured the distance
from the edge of the base plate to the edge of the bit.
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Then transfer that dimension from the layout
line to the straight edge that my router will use as a guide or fence.
I prefer using something machined, so I know it's straight, instead of
a piece of wood. This level will guarantee the mating line between the
two pieces will be tight.
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Start nibbling away the stock, beginning farthest
from the straight edge. Be very careful to keep the router base tight to
the work surface. If it tips you will gouge up the surface of the joint
area. Now this is a large glue surface, and surely a couple of gouges won't
matter that much. Just do your best not to damage the edges or the area
closest to the fence
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When you get close to the fence, be sure there are no
wood chips between the router's base and the fence. You want this line
perfect! |
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Now double check....ahhhh perfect! |
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After the first half is done, I take the mating
piece, cut the angle, in this case 45 degrees, and lay it on top to check
for square.
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For some strange reason, the walls in this home
are square, so I'm looking for 90 degrees here...Nice!
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Now flip that mating piece over, and use that
same dimension to place the straight edge again. This time at 90 degrees.
The pic at left was taken after this half of the joint was cut.
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When you route and area like this, you really only have
one shot at getting it right. This is because at the beginning of the operation,
furthest away from the straight edge, the router is supported by stock
that you will soon remove. So if you don't cut deep enough, you have no
way of taking off a little more. But you certainly don't want to take off
too much! I went a whisker shy, I would rather plane off 1/64" then try
to shim it! |
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Also, when you route a field this large, you
will get ridges. No way around that. A small hand plane makes quick work
of cleaning this up.
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Ahhhhhh, looks wonderful! And it's almost perfect.
A little sanding will finish it off.
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Here is a view from the bottom. |
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This view shows both pieces. The top piece is upside
down to show the joint. |
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Ok, now lets glue it up! Keep the glue away from the
inside of the corner, you don't want any glue squeeze out messing up that
corner. Don't get too much glue on the miter either, for the same reason.
I know, lots of people keep a wet rag around to clean
up this glue. I believe this only creates more work. The glue gets thinned
and runs into the pores of the wood. This will effect how stain and finish
look. Save yourself some headaches and be neat with the glue! |
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Just a view so you can see how big this thing really
is. The long leg is eight feet long. The short leg is under four feet.
Remember earlier I mentioned making assembly easier?
This is why, see how my bar clamp is placed on the short leg? If the joint
was cut the other way, with the first cut on the short leg, you would need
a much longer bar clamp. Either way will work, but why lug around an eight
foot bar clamp? |
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Ok, Now I'm going to make this thin shelf look heavier,
with out the expense of using thicker stock. What I did was buy 1x10 oak
for a shelf that was only going to be 7-1/4" deep. I ripped the shelf to
width, and kept the small strip, to place underneath like in the pic at
left. Doing this ensures the wood will match in grain and color.
So you end up with a nice smooth joint, you must drill
the holes one at a time. Put in a screw, flush up the pieces for the next
screw, drill that hole, then put that screw in, and continue down the length
of the joint. It would be hard work to sand this joint flush after assembly,
especially in the corner, so working the joint during assembly makes less
work later on. |
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To drill the holes quickly and accurately, I
like to use my tapered drill bits and my insty-drive
set from Rockler. Mine is an older model and looks different but it
does the same thing. The system allows you to drill a hole, then pop on
the driver to put the screw in, then quickly change back to drill another
hole.
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I do this step dry, without glue. It takes awhile
and you don't want glue dripping on the face of this joint. Also I keep
the screws well back so when I round over the top and bottom, the router
bit won't hit the screws.
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So after I drill all my holes and have all the screws
in, I take them all out, and head to my router table with a V-groove
bit installed. It only pokes out 1/16th of an inch or so.
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I set my fence so there is about 1/16th of an inch between
the groove and the face side of the joint. During assembly I will keep
the glue behind this line, and when the screws are tightened, any extra
glue that would squeeze out onto the face, will be caught in this "glue
gutter". |
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The top pic here shows glue squeeze out on the
inside of the joint where it won't be seen, but the lower pic showing the
face is spotless!
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With a little stain and finish, it don't look half bad! |
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Here's the left side.
Takes up lots of space in the shop! |
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