Kreg RAC ain't right-angled

[Anna]

Trying to assemble the base for some built-ins using pocket screws, but my right angle clamps are both off by a few degrees (<90 degrees). Anyone have any idea what I'm doing wrong?

Thanks.

[LCHIEN]

Trying to assemble the base for some built-ins using pocket screws, but my right angle clamps are both off by a few degrees (<90 degrees). Anyone have any idea what I'm doing wrong?

Thanks.

never used those before but it appears that the clamp actually will be at 85 degrees to the plane of the bottom piece. The prong in the clamp is designed to go into a pocket hole which is normally 15 degrees off vertical. It's close enough to vertical to pin a vertical board to a horizontal member as shown in the kreg picture. Put a screw into another hole (you have to be using at least two pocket holes for this to work) while holding them together with the first hole and the clamp.

If your work is not sawn absolutely square then the joint won't be square.