A friend of mine let me borrow his biscuit joiner over the weekend to try it out. I thought I would write up a quick article on how to use a biscuit joiner. The following steps will help describe how I use a Biscuit Joiner.
The two boards I joined used the Biscuit Joiner were going to be a table top, so I needed both of them to be the exact same thickness. I sent both of my boards through a planer several times until they came out right at 3/4 of an inch. I would like to also mention that if you are using raw wood from a kiln, or hardwood/lumber store (not a big box store like Lowes or Home Depot) the edges of the wood will be rough and will need to be cleaned up using a jointer or a table saw.
Lay the boards out on a table edge to edge and draw a line connecting both pieces of wood where you want the biscuits to go. Its a good idea to place a biscuit every 8 inches for added strength. With the lines laid out, position the biscuit joiner so that the indicator on the fence lines up with the line on your board. Set the height adjustment fence so it rests on top of the board. Moving the fence up and down determines where the slots are going to be cut in the wood. This is especially important if you are using a Biscuit Joiner for T-joints. The angle/bevel adjustment fences allows you to position the Biscuit Joiner to cut on different angles. This is a really important feature for cutting biscuit slots on your miter joints for added strength.
Before we cut the biscuit slots, lets double check the slot depth is on the correct setting. I will be using #0 biscuits for my test boards. With both fences set , the depth knob on the correct biscuit size and the board clamped to a workbench, turn the Biscuit Joiner on and slowly push the joiner forward, cutting into the wood. Do this for the remaining lines on both boards.
Now that we have matching holes on the two boards, it’s time to add the glue and biscuits. When the biscuits come in contact with glue, it causes them to expand which adds strength to the joint. With the biscuits in and both boards joined, throw a set of clamps around the boards. Here’s a little tip i learned about removing the excess glue during glue-ups. Let the glue sit for about 20 minutes, or until it starts to become solid, and take a putty knife and scrape the glue off. It should literally “pop” off, leaving you with a clean surface. If you whipe the glue off while it is still wet, it will smear into the fibers leaving a surface needing to be sanded.
I found this quick but informative video that shows what I talked about above.