A “Trick of the Trade” from the February 2011 issue of Popular Woodworking Magazine:
is a trick that I’ve developed to help keep holes perpendicular to the
surface when drilling by hand, either with a brace and bit or with an
I’m not very good at lining up my drill with a
try square, so I made a fixture that I call a “mirror gauge.” It’s made
from two pieces of 1/2″ MDF – one board is 5″ x 7″ and the other is
5-1/2″ x 7″. The two pieces are butt-joined with glue at 90º.
two pieces of inexpensive mirror slightly smaller than the boards, then
glue them to the faces of the MDF with mastic or mirror adhesive. I
drew perpendicular vertical lines in the middle of each mirror with a
marker. The lines provide a reference so you can see when the bit is
You can also use the mirror gauge for squaring chisels when dovetailing or mortising.