 This
tutorial builds on the techniques demonstrated in
the Through Dovetails tutorial. Some techniques
demonstrated in the Through Dovetails tutorial are
not repeated here so the reader is advised to review
the Through
Dovetails techniques before starting on
Half-Blind Dovetails.
It's not that half-blind dovetails
are harder to make than through dovetails - I
actually find them easier. It's just that I did the
through dovetails page first and I didn't want to
repeat some of that information here.
The tools and equipment for making
half-blind dovetails are essentially the same as for
the through dovetails. Refer to my page on through
dovetails for the list of tools, and a discussion of
each.
The only tool(s) I might add are one
or more "special" chisels to clean the corners of
the tail sockets on the pin board. Because of the
angle of the sockets, it's difficult to get a
regular chisel into that corner to clean out the
waste.
A small skew chisel works well, but you need
two of them, a left and a right. The other option is
a fishtail chisel. See pics below.
You can make your own skew chisels very easily from some
inexpensive 1/4" chisels. Just grind the cutting edge into a
skew. I show two Irwin chisels in the picture, which cost me
less than $10 each. You don't need expensive chisels because you
won't use the skews very much. The
fishtail has the advantage of only requiring one chisel. The one
shown here is a Blue Spruce, which is way overkill for this
application. It's a good chisel, very well made, but very
expensive - this one is about $85. An alternative is a flat
fishtail carving tool. Pfeil makes a #1 fishtail - choose either
the 6mm and 8mm (I'd get the 8mm) - for about $30.
The limit on the fishtail is the amount the head sticks out from
the shaft (on the side). If there's not enough protrusion, you
won't be able to get the fishtail flat against the back of the
tail socket, and that means you won't be able to clean the
corner out well. The skew essentially always works. And that's
what I'd recommend you get - two skew chisels (left and right),
not wider than 1/4". You begin
half-blind dovetails in exactly the same fashion as through
dovetails - by preparing the stock. It must be flat, of
consistent thickness, and cut square on the ends.
Mark the
outside of the boards and indicate which is "pins" and which is
"tails". Like with through dovetails, this will help keep you
out of trouble.
Our first step is to mark both the
pin and tail boards with the marking gauges. But
this time, the tails will not go completely through
the pin board. But how far should they go, if not
all the way? We're dealing with 3/4" stock here so
we know the tails have to be less than 3/4".
One
common depth is 1/2" because you're usually trying
to achieve some inside dimension, such as the the
inside dimensions of a bureau. Your tail board has
to be the inside dimension PLUS twice the length of
the tails (one tail on each side), so people use
1/2" because it's easy to calculate and provides a
strong enough joint. |
