Step 1

Measure Windowsill
Measure the dimensions of the windowsill. Make sure to begin with a fairly thin-gauge copper, such as 22.
Step 2

Mark Measurements
Mark the measurements on the copper.
Step 3

Score Copper
Score the copper with a knife or blade.
Step 4

Bend and Break Copper
Bend and break copper to size by hand.
Step 5

Create a Bend
After cutting the copper to size, slide it in the hand brake and pull the bar down to create the bend. Repeat as necessary.
Step 6

Place Copper on Windowsill
Apply carpenter's glue to the windowsill. Place the copper sill into place and press down.
Step 7

Nail Copper Into Place
Nail it into place using copper nails.