What is this wood joint called and how difficult is it to accomplish? What tools would I need beside a regular saw?
It would be with 2"x4" wood over 4"x4" wood.
Best Answer
The 2x4s are joined with a half-lap joint (or a variation on a scarf joint). It's unclear from your diagram if there is any joinery holding the 2x4s down to the 4x4 or if they just rest on top of the post.
Not sure what you mean by a "regular saw", but half laps can be cut by most saws - circular saw and table saw are most common, though you could use a handsaw as well. Simply run the saw across the board multiple times, removing a sliver each time. A bandsaw (or jigsaw with a long enough blade) could be used by tipping the workpiece on its side and cutting the material away that way.
You could also use a chisel to cut that joint, as well as a router.
I know this isn't the answer you want to hear, but I don't think priming and painting will hide the tape.
Before you apply any more primer, I'd add another thicker coat of mud. Slather on the mud thick first - it doesn't have to be smooth. Then smooth it out by angling your 12" knife so it's almost parallel with the drywall as you drag it along the surface. You'll have to press fairly firmly in order to avoid air gaps appearing in the thick coat you're smoothing out.
You may have to get a feel for it. If you push too hard and can see the tape again, redo that section until you get it just right.
Wait for the thicker coat to dry, then sand the edges as smooth as you can get them. Very carefully/lightly sand over area covering the tape if you didn't get it quite smooth. You may need to do a second coat along both sides of the thicker coat to make it join the drywall surface smoothly.
Best Answer
The 2x4s are joined with a half-lap joint (or a variation on a scarf joint). It's unclear from your diagram if there is any joinery holding the 2x4s down to the 4x4 or if they just rest on top of the post.
Not sure what you mean by a "regular saw", but half laps can be cut by most saws - circular saw and table saw are most common, though you could use a handsaw as well. Simply run the saw across the board multiple times, removing a sliver each time. A bandsaw (or jigsaw with a long enough blade) could be used by tipping the workpiece on its side and cutting the material away that way.
You could also use a chisel to cut that joint, as well as a router.