All holes required to fasten down hardware was filled with epoxy before redrilling.
If leakage occurs in the future, the balsa core is not compromised and will stay dry. I predrilled the holes using variable speed with a 5/8" counter sink bit - then use a 5/8" inch forstner bit to drill the balsa out. Then filled the holes with epoxy thickened with collidical sillica, I used a 50 ML medical shringe to push the epoxy in. I used masking tape to seal off the inside so that the epoxy couldn't ooze out.