Anodised aluminium retains corrosion resistance and increased strength for years. Corrosion problems in anodised aluminium, generally, only occur in areas where aluminium has been bent. However, multiple applications require you to bend aluminium pipes. If you need to bend anodised aluminium, keep in mind that anodising forms a surface layer of oxides with diamond-like hardness. Therefore, bending results in "crazing" -- fine, hairline surface cracks. Nevertheless, you can successfully bend anodised aluminium using typical protocols. Large aluminium pipes require a conduit bender, but you can use the protocol below to bend pipes 3 inches or less in diameter.
Draw the desired curve of your aluminium tubing on a piece of plywood with markers. Use your jigsaw to cut out the shape. Use C-clamps to clamp the wood to a workbench.
Tie fishing line to one end of a spring and insert the spring into the aluminium tubing. The fishing line makes it easier for you to remove the spring after bending the tubing.
Place the tubing on your wooden shape. Cut the tubing to match the beginning and end of the shape. Bend the tubing to match the curves of the wooden shape. If possible, use only one smooth motion to bend; starting and stopping increases the likelihood of not obtaining the desired curves.
Remove the spring using the fishing line.
- Since bending anodised aluminium tubing results in surface cracking and reduces corrosion resistance, consider de-anodising the tubing before bending, then re-anodising it, depending on whether you need your tubing to be corrosion resistant. De-anodising and re-anodising are inexpensive and fairly quick processes, although they do require a degree of skill. Alternatively, for cosmetic reasons, you can paint over the post-anodising cracks on your tube surface.