What You Should Know About Wood Joints

You can have a more finished and professional look to your work by using joints instead of screws and nails. Here are some of the basic joints used in woodworking.

Butt JointsThe butt joint is the simplest of the woodworking joints, and is very easy for beginners to master. The joint consists of two board ends that are pushed, or butted, together and held with nails, screws or glue. Simple wood boxes are often constructed with butt joints. While the butt joint offers a quick finish, it does not offer structural strength in most cases. If a butt joint held together with nails is required to bear much weight, the nails may soon pull out of the wood.

For beginners, though, the butt joint offers an easy way to complete a project without expensive equipment or in-depth woodworking knowledge.

Dowel JointsThis technique is ideal for joining two flat pieces together to form a larger flat surface.Take two pieces of equal length wood. Decide now which side will be the top and which the bottom for each piece and mark the top side of each so that you do not forget.

Clamp both pieces together, one on top of the other, with the bottoms face to face in the middle. When clamping, ensure that the two surfaces along which you plan to join these pieces of wood are level with each other (see diagram
one).

Draw a line down the middle of each surface to be joined. This must be exactly the same on both pieces of wood, otherwise when they are joined there will be a step at the join. Once this line has been drawn, use a set square and mark lines across the grain of the wood. The intersection of the length and width lines will show where the dowel holes will be drawn.

There is no hard and fast rule for how many dowels should be used. However, the heavier the weight of whatever will be on the surface, the more dowels should be used. Typically, one dowel per foot is a good rule (with a minimum of two).

Once these lines have been drawn you can then proceed to drill the holes at the marked intersections. The drill bit used should match the diameter of the dowel being used, thus ensuring a tight fit.

As for the dowel itself, you can either make your own small dowels from a longer length, or you can buy dowel made specifically for this reason. The latter option is a far better solution, as the small dowels are beveled at the ends to make it easier to but them in the holes, and are ribbed to allow the glue to bond more efficiently. Each hole should be just over half as deep as the length of the dowel being used. Once the holes have been drilled, glue one end of each dowel into the holes in the first piece of wood. Then place
glue along the full length of the second piece, ensuring that some glue falls into each of the holes.

Unclamp the two pieces and push them together, ensuring that the two top markings are facing up. Once done you should clamp tightly overnight. Be careful when you clamp them to make sure that both pieces remain flat and
do not try and warp upwards. To avoid this, it may be necessary to clamp the entire piece down to a flat surface.

Dovetail JointsThe dovetail joint is possibly the best joint that you can use to join two pieces of wood together at a right angle. Not only is it a very strong joint, but it also adds to the appeal of the woodworking project.

The simplest way to create dovetail joints is to use a router and a dovetail template jig. The latter is available from any good home improvement store and can cost as little as $70. Its well worth the investment if you plan on doing many dovetail joints in the future.

Arrange the three pieces of the drawer or box as shown in the first diagram and mark the inside and outside of each piece. In addition, mark the ends of each piece as it is imperative that when cutting the dovetails the correct two
ends are cut at one go.

Clamp the front of the drawer and one side into the dovetail machine as follows: the left side of the drawer should be clamped under the front clamp (pointing upwards towards the template) with the inside of the drawer pointing out; the front of the drawer - again with the inside pointing out -should be clamped under the top clamp so that it butts up against the left drawer.

These two pieces should be staggered slightly, rather than being aligned exactly. The precise measurement will depend upon the particular dovetail machine that you are using, and this distance will be supplied with its manual. However, it should be roughly in the region of 7/16 inch. Once everything is tightly clamped in place, use the router to cut around the template, following the direction of the arrows in this diagram.

You can then join the boards together at the joints securing with glue and clamping overnight. It is well worth practicing with scrap wood before trying the above procedure on any project as it will take a while to get the exact measurements (such as the depth of the router cut) perfect.

If the joint is too loose, slightly increase the depth of the router cut. If the joint is too tight (remember that you still have to squeeze some glue into the joint), slightly decrease the depth of the cut.

Slotted Tenon JointsSlotted tenon joints are typically used as a method of fixing shelving into a units shelf walls. However, it can also be used for a number of other purposes. The idea of a slotted tenon joint is that only one of the two pieces of wood needs to be modified in order to attain a good, tight fit. To do this, one piece has a slot made into it that is the same width as the thickness of the second piece of wood. This latter piece of wood can then be pushed into the groove, making a strong, right-angled join.

The most effective way of creating the groove (or slot) is to use a router. Although a chisel can be used, the quality of finish will not be the same (and it takes far longer to make).

Be careful when making the slot to ensure that it is not too wide, otherwise the joint will not be tight enough to work. It is far better to start with too tight a groove and then widen it.

A router is not always the best tool to use however. If the groove is to hold a piece of 1/4 inch (or smaller) plywood, you should use a circular saw instead, changing the depth of cut to as little as 1/4 inch. This smaller cut is ideal when making the joint for a back panel of a cabinet, such as a bedside cabinet.

Now that you have some basic information, let’s get started with that first project!

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