When it comes to holding a dovetail joint together, using glue is one of the better options. While dovetail joints are known for their stability and secure hold, for larger pieces it is usually better to fix them in place. Gluing the parts together is not very complicated, but will ensure that the joint holds for longer.
Preparing the Blocks
The dovetail joint should be held in a clamping block while the glue is being used. Take a piece of wood which is similar to the joint, and place this in the clamp. You should then be able to fit the joint into position so that the spare wood holds the faces of the joint. Hold the joint together firmly, and check for signs that the wood is too tight. If it is too tight it will be cracked or splitting.
Adding the Glue
Once you are ready, you can then drop a small amount of glue along the edges of the joint, and spread it out using a glue brush. Apply as much glue as possible to the joint, and then apply the clamps and the clamping wood, fastening the clamps until they are holding the dovetail joint tightly. You may find that glue will be squeezed between the joints, but this is not a serious problem, and can easily be wiped away.