Making picture frames is a popular woodworking project but it's not alway easy to decide how to fasten the corners that are often edge grain wood that often doesn't readily take many woodworking glues to secure it. Mechanical fasteners are popular like screws, nails and staples and sometimes splines are cut into the corners then wood veneer is glued into the splinces to make a very strong corner, and decorative as seen from the edge, which picture frames are seldom viewed from. Using rabbets is less common, but is equally as strong as splines, and they add a different look to the picture frame. Cuting rabbets into corners is not limited to picture frames, it could also be used in doors and door frames and other edging and surround applications. Sometime dowels can also be added to the rabbets, but this can also look "over done" in terms of looks of the frame or door.
Watch this and other similar videos on YouTube - https://youtu.be/0SmyNi804ec
The version shown in the video is a common design, simple to make and works well. The minimum dimensions ...
The dimensions for the back board should be at least 14 inches wide and 12 inches high, a bit more will not hurt. This will allow adequet space for fastening the 45 degree support arms and the plates that will secure the jig to the table saw fence. The arms I used were 1-1/2 inches square and 12 inches long and be sure to cut a 45 degree angle cut in the bottom to allow them a closer proximity to the table saw's deck. The other components that will secure the jig to the table saw fence need to be cut to accomodate the fence you have on your saw.
I started off by marking the locations of where the support arms, and the components will be positioned on the back board. In my case I used MDF for the upright piece which means holes had to be drilled through the MDF so that screws could be used to fasten the other compontents together. MDF has many benefits, but holding screws is not it's best suit.
In terms of attaching the components, I attached the support arms first, then positioned the jig in place, over the table saw fence *** making sure *** that there was a wood veneer under the the upright as I wanted the upright to ride only on the fence, NOT on the deck of the tablesaw. I have found there are too many cases where jigs can get jambed or make quirky cuts when they are allowed to ride on the table. Best, if you can, to have them riding on the fence only.
After the arms were secured and at 90 degrees, I attached the piece that would be the component that is actually riding the top of the fence, and then the final component, which was the backer to the fence that keeps the jig secured to the fence.
I have found using this jig that the best results are when you cut the rabbet component first, that is, the wood that is going to be inserted into the rabbet you will be cutting. It is much easier to make a few very small cuts into the edges of the frame to get the size the right depth for the wood to lay into. The wood insert should lay flat in the rabbet and be flush or ever so slighly above the main part of the frame. The wood that is used as the insert wants to be tight, straight grained wood that will round at 90 degrees to the wood in the picture frame to give the strongest support. The wood that you use for the inserts wants to be at least 1/16th thick and more is even better, the reason for this is that if the wood is too thin, there is a chance it will shatter or come away at the very tip of the corner of the frame due to a lack of wood structure that holds it'self together.
This quick and easy jig can be used for all sorts of corner applications for decoration and streght and is easily adaptable to many different configurations.
Copyright Colin Knecht