For our entire timber joints section we are very grateful to www.technologystudent.com for allowing the use of their material. All images and text are © V. Ryan 2002
These are good examples of ‘Halved Joints’. In this type of joint one piece crosses over the other.
These two ‘bridle joints’ are used when a light frame is needed. for example, a picture frame. One part of the joint fits into the other part and is glued permanently in position.
MORTICE AND TENON JOINTS
Below are two examples of ‘mortice and tenon joints’. These are used when making tables or cabinets and they are very strong when glued together. There are many different types and a larger feature on this type of joint appears below.
THE MORTICE AND TENON JOINT
The common mortice and tenon joint is normally used in the construction of tables and chairs. The joint is reliable is a suitable glue such as PVA or cascamite is used. For more information re cascamite keep scrolling down. The joint seen opposite can be strengthened in a number of ways including the use of dowell rod (seen below). The problem associated with the basic mortice and tenon is that over time the joint can come apart especially if it is expected to hold the weight of a person - such as the joints of a chair.
DOWELLED MORTICE AND TENON JOINTS
This is another example of a mortice and tenon joint. However, in this example a piece of dowel rod is drilled through the mortice and the tenon. This helps keep the joint together even when it is under great pressure. This is used as a joint on chairs and other pieces of furniture so that the joints do not break apart when extra weight is applied.
To the right is another way in which dowels can be used to form a joint. Modern pieces of furniture are often jointed in this way. It is a permanent method but it is not the strongest joint as the parts can eventually pull apart, especially as the joint becomes old. Modern glues that are very strong have meant that this joint is often used to quickly fix parts together.
THE SECRET HAUNCH MORTICE AND TENON
If the mortice and tenon joint is to used as part of a frame a secret or sloping haunch is used. The tenon does not show on the outer side of the joint and it gives greater gluing area, adding to the overall strength of the joint.
WEDGED MORTICE AND TENON
This is a very strong and attractive joint. The tenon has two slots and when it is pushed into the mortice wedges are tapped into position. The wedges hold the joint together firmly and they also give the joint an interesting look.
MAKING A MORTICE AND TENON JOINT - THE MORTICE
The construction of a plain mortice and tenon joint joint is shown opposite. This type of joint has a wide range of uses and is particularly useful when manufacturing furniture. Several types of mortice and tenon joint exist. The marking out and cutting of all the mortice and tenon joints are based in this simple joint. Below is a stage by stage account of the marking and cutting of the mortice part of the joint.
The mortice gauge is a special type of marking gauge and it is used to mark wood so that a mortice can be cut into it. The diagram to the above represents a typical mortice and tenon joint. The mortice is marked out using the mortice gauge although it must be set to the correct size of mortice chisel very carefully. A mortice chisel is then used to remove the waste wood.
The mortice gauge is normally made from a hardwood such as rose wood with brass being used for the parts that slide along the stem.
|Animated Mortice Gauge|
MARKING OUT A MORTICE
The distance between the fixed spur and the adjustable spur is set so that it matches the width of the mortice chisel. The width of the mortice chisel should match the width of the mortice to be cut in the wood.
A try square and a marking knife are used mark the lines at the top and bottom of the mortice.
The stock of the mortice gauge is pressed against the side of the wood. It is then pushed along the wood until the mortice is marked out correctly.
The mortice chisel is then used to break the surface of the waste wood by gently tapping the handle with a mallet.
The waste wood is then slowly removed, this time, by applying more force to the handle of the chisel with the mallet. The waste is removed until the entire mortice hole has been cut.
Chisel amimation by V.Ryan
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