Compound 45

[Matt]

I can't seem to wrap my head around it. 2x 3/4 ply both cut at 45 makes a 90. I have busted thru every time. The angle is cut as if doing molding not like a picture frame. I just dont want to see ply edges.

Depth collar set to 3/4. ??? Yahhhh. Need to make a box.

[John Schaben]

I'm not a big advocate of pocket hole screws on 45 degree angles. Pic shows why, the red line is the path of the screw, 15* angle and set to exit the pocket board dead center.

About all you can do is move the screw closer to the corner and use a shorter screw.

[Matt]

What's the best way to do this? Glue and nails?

[John Schaben]

Hi Matt - For plywood, I prefer rabbet or locking rabbets. The rabbet shown will show only about half the edge. If you have room inside the box you can miter the corner and use a corner block (shown in red at 1/2" thickness)  with glue and short screws or brads. Screws and brads just hold it till the glue sets up and reinforces the corner. A lot depends on how large the box is and how much weight it is expected to handle.

I also like to use Gorilla Glue (polyurethane, the foamy stuff) on plywood as it seems to hold better on end grain.

 

Matt said:

What's the best way to do this? Glue and nails?