Trimmed and sanded edges of skins on rear spar. Cut and prepped scarfs for 3/32" skins for main spar. The main spar has three different thicknesses of skins. It starts at 6 mm at the root, reduces to 4 mm over the middle third, and then done to 2 mm (3/32") over the outboard third. I could only prep the 3/32 skins as I haven't yet ordered the 4 mm and 6mm ply yet.