Sheet metal brakes and aluminium siding brakes place clean bends on sheet aluminium. One downfall to a brake is the cost and room required to house the equipment. Hand bending without mechanical equipment produces clean bends with a minimal amount of tools. Softening the aluminium sheet reduces the amount of force required to make a clean bend.
Set a fire extinguisher in the area you will work in.
Place the aluminium sheet on a work table. Pull the sheet until the bend area extends 6 inches past the edge of the table. Set a length of 2-inch angle iron across the sheet. Align the angle iron with the edge of the table. Clamp one C-clamp on either side of the aluminium, making sure to clamp both the aluminium and the angle iron to the table.
Light an oxyacetylene torch with a striker. Turn down the oxygen valve to produce an acetylene-rich bright orange flame. Run the flame over the bend area of the sheet while holding the tip of the torch 12 inches from the sheet's surface to coat the aluminium with a black coating of carbon.
Open the oxygen valve. Adjust the torch flame to a dull blue exterior flame with a defined bright blue interior flame. Run the neutral flame over the aluminium sheet. Stop heating the aluminium when all carbon deposits are gone from the sheet's surface. Turn off the torch. Allow the aluminium to cool to the ambient air temperature.
Release the C-clamps. Align the bend area of the aluminium sheet with the edge of the table. Clamp the metal to the table, making sure the edge of the angle iron aligns with the edge of the table.
Press one edge of a wood board against the angle iron. Press toward the ground with both hands to bend the aluminium sheet. Inspect the bend. Hit the bent area with a dead-blow mallet to tighten the radius of the bend if you require a tighter bend. Release the clamps. Remove the bent aluminium sheet from the work table.
Softening (annealing) is not required when bending thin sheet aluminium.
Tips and warnings
- Softening (annealing) is not required when bending thin sheet aluminium.