A siding brake bends aluminum or bendable vinyl siding to the angles you want using leverage from a hinged joint. A purpose-made brake isn't necessary if you are going to be bending only a few pieces of coiled siding. Use scrap lumber to make a brake that is effective when only a few bends will be necessary. This method is recommended for do-it-yourself siding repair or other small projects. A siding brake is more effective and much faster for large or professional jobs.
Cut two 2-foot-long sections of 2-by-4 lumber using a saw.
Screw hinges to one of the 2-inch sides of one board. Place the hinges so that another board can be attached to the other side of the hinge and the boards can still lay flat together. Put a hinge at each end of the board and one in the center.
Lay the board with the hinges down so that the 4-inch side is on your work surface and the hinges are pointing up. Stack the other board on top of this one. Screw the hinges into place.
Lay the homemade brake on the work surface with the two pieces of wood open and the hinges facing up.
Use a saw or snips to cut the coiled siding to length. Align the siding's bend point with the hinged joint of the homemade brake. Lay a piece of scrap wood on top of the metal, and clamp the scrap lumber, the metal and the bottom hinged board to the work surface.
Lift the other hinged board, and apply pressure to the coiled siding with the wood. Bend in this manner until the desired angle is achieved.