I have been searching and searching for stylish balcony boxes for the house (classic falun red with white corners) without finding anything. These will be used for flowers and vegetables and will therefore be filled with soil. I have considered having a skilled sheet metal worker bend some in galvanized 1mm sheet. Lindskog and Gyllström in Gothenburg are willing to do the job, but it will be expensive but well-made. One option is to make them in spot-welded blackplate and send for galvanizing.
It occurred to me that it should be possible to custom-build in 10-12 mm pine plywood. The angular result works with the house style. These are epoxy-treated on the inside and top edge, so that they become absolutely watertight. The outside is painted with regular oil-based exterior paint to allow breathing. Drainage at 1-2 cm from the bottom should ensure it doesn't fill with water unnecessarily. Brackets for hanging will be easy to solve.
Any thoughts?