How To Cut Cross Lap Joints
By: Chelsea Rodgers
The key to projects like tables are half lap joints, also called cross lap joints. What are they? That's when you cut halfway through the width of the piece of wood on both pieces of wood the same thickness of your piece of wood, and they slide together into a super solid joint. Making a
cross lap joint is pretty easy. You can do it with our miter gauge (MLCS item #9443), or a regular old table saw blade. If you're doing multiple cuts and big ones using a dado head the Multiform Crosscut Sled is the way to be more accurate and make the job a lot easier.
The Multiform Crosscut sled is two tables in one. It's got a pivoting fence with built in angle gauge, along with a fence and top mounted T-track that you easily attach hold downs (MLCS item #9796) too. Replacement zero clearance inserts accommodate blades and bits up to 4 ½” wide. With it’s “no cut through” design, and the 28” adjustable Miter Bar, the Multiform Crosscut Sled will give you smooth controlled movements every time.
To make cross lap joints, the first thing you want to do is install a dado blade, like the MLCS Dado Clean out Router Bits, (MLCS item #5381-5384, 7684), available in 5 different diameters you will be able to carefully adjust the thickness of this cutting head so it's identical to the thickness of the wood that you’ll be using. Then, this is where the a zero-clearance insert that the Multiform Crosscut sled has comes in handy because it reduces tear out.
The next step is to set the cut to half the width of your board. To help you get that measurement perfectly, use the Engineer Square 3- Piece Set (MLCS item # 9664). It’s a good idea to check the setup with a test cut. Use some scrap pieces that you have saved and make two cuts. Put them together and make certain that your set up is exactly what you are looking for. If the pieces don’t quite fit like you want them to, just make the necessary adjustments to your dado blade. Keep in mind though, these adjustments are very minimal. If your happy with your test cuts, then grab your piece and cut away!