Never use biscuits on 1/2″ or thinner panels, because the position of the biscuit will be telegraphed to the surface. Randy, Central MN. The “Telegraphing” everyone complains about is simply a function of the biscuit absorbing water from the glue and swelling up a bit AND of someone surfacing that piece before the moisture equilibrated which would allow the swelling to go back down. “…in his brain, which is as dry as the remainder biscuit after a voyage, he hath strange places cramm’d with observation, the which he vents in mangled forms.” -Shakespeare, “As You Like It”. Have your say… Forum Topics Woodworking Skill ShareYour woodworking skills are displayed for several lifetimes in each project.
Larry, I always used to fill the biscuit slots with glue but I had a wood shop teacher tell me this was not necessary. On another note, the only time I even use biscuits is when there is some bowing in the stock. I cut slots where ever the stock is bowed and the biscuits help with alignment while glueing.
Properly-cut biscuit joints are strong and accurate, particularly when cutting slots with a woodworking tool called a biscuit joiner. When glued into slots precisely cut by the biscuit cutter, and the moisture from the glue causes the biscuit to swell and tighten the joint. As a general rule, try to use the largest size biscuit possible, as this will provide the greatest amount of strength to the joint.
how to use a biscuit joiner to make a table top Related Question:
Do I need to biscuit joint a table top?
Biscuits can be used to join the ends of boards to edge or face grain. They will definitely provide more strength than glue alone, but not a lot. If your boards are too narrow, you can reinforce the joint by adding the biscuit on the back side of the face.