||There are a vast array of traditional wood joints. Some of
these, however are not in common use by woodworkers and manufacturers, so
what useful purpose do they serve?
All of my wood working skills, if that is the appropriate word, are self
taught, largely by simply getting on with it and experimenting. I have come
across a strongly held belief that that real wood working is about the
joining of timber by cutting shapes into it, which allow the two parts to
interlock. The only acceptable non wood component is adhesive or glue.
Nails, bolts and screws are alright for joinery (floorboards, studding and
other building related work), but using them for cabinet making (furniture
in general) is tantamount to an admission of having no true woodworking
knowledge and skill.
Personally, I am not totally in agreement with this. The number one rule is
to follow your own preferences and make sure that you enjoy the experience.
All these fancy joints, such as the dovetail, came about because of the
constraints of technology and probably the desire to show off, no doubt.
Consider for a moment that you have to form a strong, reliable wood joint,
but the two modern classics of PVA adhesive and wood screws don't exist.
There is animal glue (the term glue is often used universally, but strictly
speaking refers specifically to animal glue), but this is not as strong or
long lasting as modern adhesives. What can you do? This question led the
craftsmen (obviously women weren't allowed to do woodwork unless it was
related to housework and child rearing) of history to invent these cut
joints of varying degrees of sophistication.
However, today such elaborate joints are largely unecessary because you can
trust the strength of the adhesive. As you become more able and confident,
it is likely that you will want to try varying methods, and in time you will
discover your likes and dislikes. Indeed, there is a certain satisfaction in
creating work without screws and nails, but this shouldn't put you off their
use. My all time favourite joint is the housing joint, largely
because it is relatively quick anand easy to cut.
This is a simple case of pushing one piece of timber squarely against
the other. This is what you are doing when you use screws or nails. You
could use either of these on their own, but they are stronger and stiffer
when used in conjunction with PVA adhesive. Of course, you might want to be
able to disassemble the piece in the future, therefore screws alone are
Nails come in various guises. Round wire nails are the norm for joinery,
lost head or oval nails are for the higher quality finish needed in cabinet
making. Blunt the nail head with the hammer before driving. This reduces the
likelihood of splitting the wood. Keep away from the ends and edges, as this
greatly increases the possibility of splits. Knock the heads of lost head
and oval nails below the surface with a punch and fill with woodfiller of
Screws are stronger than nails. Choose countersunk heads. Drill a pilot hole
in the top piece of timber slightly bigger than the shank of the screw to
allow it to enter the hole easily. Drill a countersink hole on top of this
with a countersink bit or larger straight bit. Align this screwhole with the
piece to be joined and mark through it with a bradawl. Drill a pilot hole
equivalent in diameter to the screw shank to a depth slightly below that of
its length. Driving in screws without predrilling is possible but often
causes damage to the screwhead. Fill the countersink holes when finished.
This joint is suitable for joining cabinet corners and just about any
vertical to horizontal component, such as fence posts and rails. A housing
is a groove running across the grain.
The simplest form of this is a through housing. It goes all the way
through from one edge of the timber to the other. Take the piece that is
to be joined and place it either edge or end on, whichever is appropriate,
in the correct position where the joint is to be cut. Align at 90o
by using an engineer's square. Draw a line either side of it. These two
lines represent the perimeter of the housing. Saw down to the required
depth, approximately one third the total thickness of the board, on the
inside of these two lines. In thicker timber, such as fence posts, it is
reasonable to increase the depth of the housing to half the total thickness.
Sawing can be done by hand with a tenon saw, but the easy way to cut a
housing is with a circular saw, set to the desired depth. Remember that the
depth of a cut joint needs to be added to the dimensions when marking the
length of your boards. Either way, cutting accuracy can be improved by
clamping a piece of scrap straight edge timber across the width of the board
to use as a parallel guide. Always place blocks between the work piece and
clamps to avoid damage from the clamp pressure.
Once the cutting is done the waste material should be removed using a
chisel. Choose one that is equivalent or slightly less than the width of the
housing. Begin by holding it bevel side down, moving from the outside to
middle of the joint to avoid breakout of the timber at the edges, which is
very easily done. Give yourself extra inital power by gently hitting the top
of the chisel handle with a mallet. Holding the chisel upside down avoids
the tendency of the blade to dig in, causing the blade to sink below the
required depth of the joint. Do the same from the opposite edge. The entire
process of removing the waste material is made easier by making a number of
saw kerfs (cuts with the saw blade) through the joint, if you have a
circular saw. Once the majority of waste is removed, turn the blade bevel
side up, gently finishing it to a smooth, even, flat surface with just the
power of your hands.
A through joint is clearly visible in the finished work, and if it isn't
done very cleanly and accurately, you might consider the results to be
disappointing. The solution is a stopped joint. This simply means that you
don't go all the way through, so you can't see the housing. However, the
tool required to do this job easily and effectively is a router, because it
is difficult to saw without going from one edge to the other. Mark out the
joint in the same way and set up a parallel guide, but this time remove the
waste with the router set to the required depth.
For housings at the end of a workpiece, such as cabinet corners, you have
two options for modifying the joint. The simplest is to cut the housing at
the very end in the normal way, turning into a lap joint, because it only
has one side to the groove, not the usual two. The more sophisticated way is
to cut the joint to one half of its actual width, leaving some of the
material remaining at the end of the board. This leaves you a true housing,
but the piece to be joined with it must have a matching shoulder cut into
it, half the thickness of the board, which is equal to that of the housing.
Such a joint must be cut to allow an easy fit, because trying to force the
two pieces together can easily breakout the small strip of end material.
Before assembly, housings joints should be covered with a thin even layer of
PVA adhesive. Once assembled, the joint should be held in place with sash or
T bar clamps whilst the glue dries. There really is no substitiute for
having these clamps for such work, and here lies a clear demonstration for
one of the benefits of using screw butt joints, as they pull the work pieces
together without needing clamps.