How to Make Tongue and Groove Joints
Step1: This joint is really only used for timber boards so the first thing you must do is measure and cut up some timber boards to your required length.
Step2: This step is not entirely necessary if you have some experience using a router but if not you need to mark the giving and receiving ends on your boards.
Step3: This step needs to be done with a router bench to create a successful joint and the first thing you do is start with a router bit to cut the groove. After the groove has been cut you now use another router bit to cut the tongue.
Step4: Check to see if the joint fits tightly and if it does you can now glue and clamp the boards together which will interlock from your tongue and groove joints.
Tip: You can buy lining boards which already have tongue and groove joints cut which makes this option a simpler and easier method for people with time restraints or inexperienced woodworkers.