Brief Description: Vacuum forming the leading edge skin
Normally you would get the leading edge skins with a 90 degree length ways bend with the wing kit parts. The skin is 12 feet long so that is a long bend. Both skins I have here are not really usable. One has a number rib station rivet lines drilled in the wrong place. The other one has a 75mm crack that somehow happened when I was transporting the skin down here. I could order new skins from Zenith as they are not much more than the local cost of a full sheet of 0.025" aluminium. What would cost a bomb would be to ship them from the USA to Australia.
So I brought two full sheets. The problem is then how to you get the bend in them. The plans call for a 1-3/8 inch diameter 90 degree bend. Thats about 35mm. Looking on YouTube I discovered a number of Sonex builders who bent their leading edge skin using a vacuum forming method. This method looks very achievable. So thats what I went with. And in the end worked amazingly well.
I got a 33mm OD pipe (closest size to 35mm). I added a wooden filler behind to let the sheet come together smoothly. Drilled some holes int he pipe to let the air out.Using masking tape pull the sheet together to form a tube around the pipe. takes a bit of patient work. Wrap in plastic. Conect vauum to the pipe and the vacuum pulls the sheet around the pipe and flat together. Unwrap and ther it is, magic.
Skin pulled together around pipe with masking tape
Wrap in plastic and connect vacuum cleaner. Squashed flat
