Gruelling solid riveting all day long, did both right & left main spars complete. Drilled out & corrected very few. Finished and mated spars and drilled 5 attach points out to 1/4". Spars are done! Then worked 4 more hours till 2 am prepping wing ribs & reinforcement gussets. Cutting out corners from ribs for spar caps. All wing ribs other than roots ready for assembly.