Welcome to the first episode of Join It! This series is dedicated to breaking down the simplicity and beauty of woodworking joints. From the most basic to the advanced, I show you how I do my joints with all the tips and tricks that I can offer with the joints that I am most familiar. Some joints I’ve never tried before so it will be an experimentation in learning with every passing video. So let’s break down the “half lap joint”.
The half lap is a relatively simple joint that increases glue joint surface area by as much as 85%. It all but eliminates the end grain gluing surface and introduces face grain to face grain glue ups.
You only need a small assortment of tools and accessories to make this job super simple.
You will need two pieces of dimensional lumber to the thickness and width of your choosing. You will also need a tape measure, clamp, stop blocks, flat bottom bevel blade for your table saw and either brass height bars or a digital height gauge.
To begin, first set up your cross cut sled with the two pieces of wood you wish to join. One piece will be your project piece and the other will be used as a spacer to replicate the width of your cut.
Next, set up the height of the blade using either the brass bars (not as accurate) or the digital height gauge (very accurate) to the exact half-thickness of your project pieces. Example 3/4” thick stock, you would set your blade to 3/8” high, hence the name “Half” Lap.
Now begin by making your first cut with the project spacer (the adjoining piece) being used between the blade and stop block.
Now, remove the spacer and replace it with a 1/8” brass height bar (1/8” b/c this is the exact thickness of the blade being used). This will push the blade to the other side of your indicator marks. If this is not done you will overcut your joint by 1/8 of an inch and it will be too loose.
Now I’m just using the saw blade you will need to hog out the rest of the material just moving the peace little by little and moving it past the blade making small curb cuts. You can then clean the mating surfaces with sandpaper or a chisel. If you are comfortable with your table saw, you can slowly advance the piece over the blade moving it side to side to clean the mating surface.
Now repeat this process switching out the project pieces and using the first piece now as your spacer and your spacer as your work piece. If you do this you will replicate each piece no matter what the width and they will fit perfectly!!!
Thank you and I really hope that this clears up some questions that some of you have had on how to do Half Lap Joints the easy way.
Take care and be safe in your shops. BOOM!!!