Surely, looking for how to joint wood, you have already watch in a woodworking blog or in a YouTube video that it is possible to joint the edges of the wood boards using the router table and a straight router bit. Jointing on the router table is not a technique that I will use often, as I have my DIY thickness planer, but I wanted to see if it was as simple as it seems to be.
Until now I had not tried jointing with the router table, because with the router fence I had so far I could not try this technique. But since I attached another split fence to the DIY router table fence, I can now try this woodworking trick.
This woodworking trick consists of separating the part of the split fence that is after the router bit by about one millimeter from the one piece fence. So, I insert a spacer between this part of the split fence and the one piece fence, while leaving against the one piece fence the part of the split fence that is before the router bit. You can see how I made the woodworking jigs in the woodworking projects tab on this blog.
The purpose of this woodworking trick, separating one part of the split fence and leaving the other part against the one piece fence, is to set up a configuration similar to that of the jointers. If we move the fence laterally until the split fence we shimmed is perfectly aligned with the router bit cutting edge, this shimmed part of the split fence acts like the fixed base (the outfeed table) we have in a jointer after the cutting blades. And the unshimmed part of the split fence before the blades is slightly shifted inward a depth equal to the thick of wood we are going to remove when jointing.
Jointing on the router table, trial and error:
As usual with these homemade machines, and even sometimes with purchased ones, the theory seems very simple but when it comes to jointing wood unexpected problems can appear. In my case, after several tests jointing wood boards that did not come out well, I discovered that the two parts of the split fence of the router table were not perfectly parallel. The result of this is that the wood board to be jointed does not stay flat against both parts of the split fence. Then, as seen in the following video, as it moves along the inclined part of the split fence, it separates from the straight router bit. It even separates enough so that the straight router bit does not joint the wood.
This lack of parallelism is probably due to some small deformation in the one piece fence due to the humidity in my workshop. It does not seem to be something that is going to give me problems during usual use of the router table, but it does have a great influence when it comes to performing this trick of jointing with the router table. And although it may seem simple to solve, I had to modify the shims behind the part of the split fence that works as outer table several times before I managed to get it parallel with the other part.
Once both sides of the split fence are parallel, and the jointing configuration is ready, it is now easy to joint the edges of the wood boards with the router table and leave them perfectly straight, at 90° to the faces of the boards and perfectly smooth. However, in order to obtain a perfectly smooth surface, it is advisable to check the direction of the wood grain at the infeed to the router bit before jointing. The wood grain should enter the jointer pointing outward, as seen in the pencil marks in the picture. If they come in pointing towards the router bit (you can see it better in the video), when the router bit cuts the fibers it will lift them, leaving a sandpaper-like surface instead of the smooth surface we are looking for.