When to Use a Biscuit Jointer

 A biscuit jointer is used to make biscuit joints. You use a biscuit joint when you want to join two pieces of wood so that the resultant joint is strong and reliable and without any lateral movement. The biscuit jointer cuts notches in both pieces of wood and you insert and glue a compressed wood chip called a biscuit into the joints. You then clamp both work pieces together and allow the glue to dry.

What is a biscuit joint?

There are many ways to join two pieces of wood together. The biscuit joint is one of them. It is a method of joinery that requires inserting an oval-shaped piece of compressed wood called biscuit into slots cut into the two pieces of wood you wish to join. The slots are cut into the work pieces by a power tool called biscuit jointer. The jointer has a small circular blade which cuts a half-mooned shaped slot into the work piece. The joint is filled with glue so that it swells and locks the joint in place making the joinery perfectly hidden.

Usually the biscuit jointer comes with adjustable fences which enable you to control the height of the slot. You can adjust this height and cut consistent slots on materials of the same thickness. You can also cut double biscuits when extra strength is required. Biscuit jointers also have depth settings which enable you cut biscuits of varying lengths and widths. Since larger biscuits allow for more surface area for glue, it is advisable to use the largest biscuit possible.

Making your biscuit joints

Set the biscuit jointer to the correct size of biscuit you will be inserting into the slot and ensure that the jointer is at the right height for the cut. Make sure you set the depth of cut on the biscuit jointer to half the thickness of the work piece so that the joint is right in the middle of the pieces you wish to join. While cutting, avoid wobbling by pressing down on the thumb rest at the front of the jointer. Mark the work pieces at the points you want the joints to be and make the cut in both work pieces.

 Limitations of biscuit joints

Biscuit joints are ideal when speed and consistency are more important than strength. It is great for alignment when joining two pieces of worktop but the biscuit doesn’t penetrate very far into the joining work pieces. It is the glue that’s doing most of the holding. Therefore, you may also need to use worktop bolts to obtain maximum joint strength.

Final thoughts

The biscuit jointer certainly has its place in joinery, especially when you need to make joints quickly and consistently although it’s not the strongest form of joinery. Biscuit jointers are easy to set up and to make the cuts. For example, biscuit joints will do when you are doing light duty pieces. It is definitely worth acquiring a biscuit jointer for light-duty joints but for end-grain to long-grain joints, it is advisable to use the mortise and tenon. The joint will have a great deal of glue joint surface and strength.