I am building a 1930's design that was originally built with no drain holes in the wing box spars, or the box spars for the tail or elevator. A number of builders are closing the spars without any drain holes. A Canadian builder was told by his inspector that he had to have drain holes. The holes will not alter the strength enough I assume to make any difference and better than condensation buildup inside unvented spars. I have tried using a soldering iron using a pointed tip made from 1/4" drill rod and this burns a nice 1/4" drain hole in scrap trials. Any thoughts from tech counselors or others as to vented or not?