When you're working with aluminum window trim, you may need to break the sheets to get the perfect fit. This doesn't mean ripping them in half. Instead, breaking the aluminum is simply bending the aluminum with a special tool to fit a certain application like window trim.
Measure the Trim You Need
Measure around the window for the amount of aluminum you will need for the trim.
Cut the Aluminum
Cut the aluminum to size with tin snips before you put the break in the aluminum. By doing this first, you can better handle the aluminum when it is in the metal break tool.
Place in Break
A metal break is a simple tool to operate. It has a lever that operates the two pieces that come together to form the bend. Set the aluminum in the metal break until you get the part where you want the bend.
Make Aluminum Break
Pull the lever back until you get the desired bend in the aluminum. Since aluminum is pliable, the bend need not be exact. You can still mold it a little to fit between the siding and the window.