Before making the actual picture frame for my friend Bill, I decided to make the JIG and perform some tests cutting mitered half-lap joints.
I had some pine 1 by 6 by 72 inches boards in my lumber racks. I jointed one edge flat and square to a surface. From that I ripped a width about 2 1/2 inches wide. There was enough tension in the board that it moved immediately. I decided to crosscut the six foot lengths into lengths that would give me a picture frame that would fit a 11 by 14 matted photograph. I cut two pieces 20 inches long and two others 16 inches. From these lengths I jointed a surface flat and then edge jointed and edge flat and 90 degrees square to the flat surface. Then I ran the pieces through my planer. I stickered the milled parts and let it acclimate over night.
I used double side tape to apply 60 grit sandpaper to the L-fence JIG. Afterwards I fixed the JIG to my table saw’s miter gauge. I decided to use my DADO set. I configured the DADO set to just less that 1/2 inch width cuts.
Using the Woodworker’s Journal article as my guide, I drew the layout of miter half-laps for the test pieces and also a picture frame parts from the pine lumber I milled the day before.
I began by first cutting what I labeled B parts that were the mitered pieces. I cut those parts first and used my INCRA miter gauge for this process. In the photo below the B part with the mitered ends are shown on the top-side in the image.
I took a scrap pieces of pine and cut it in half. It was milled through my planer so it’s thickness was the same as the picture frame parts. with these two parts I began taking cuts to by raising my DADO blade until I had a perfect half-lap fitting. Once I had the blade height setting, I then used my jig to make the half-lap cuts to join each of the picture frame parts.
I will used a hand chisel to clean up the half-lap cuts so these miter ends fit snugly. The picture frames has turned out quite well straight from my table saw cuts.
-- --- Happy Howie