The first parts of the fuel tank have been made. I've decided against building it from composite materials. The effort required for the strength certification was disproportionate to the expected benefits. So, the tank will be built exactly according to the original plans in aluminium, but with a slightly increased volume, as was also originally planned as an improvement. The original 230 litres will now be around 290 litres in capacity.
For the material choice, after consulting with experts, I decided on EN AW-5005 / AlMg1(B) / EN 573-3. This matches the original specification, is formable, and has excellent welding properties. For the first components, the baffles inside the tank, I had a mould made from hardwood on a CNC machine.
The first attempt to simply pull the sheet metal over the mould using an external template failed. Waves formed that couldn't be hammered out.
The second attempt, gently hammering the sheet metal over the mould, went much better. After the fourth baffle and what felt like 15 million hammer strikes later, I think I've almost got the hang of the art of metal forming.
