On Monday, May 12, 2014 12:20:40 PM UTC-5, wrote:
Using a step drill, create about 1/4 diameter drain hole in front of bulkhead where water collects.

Or, behind if the water is moving forward to get to the bulkhead! I have seen gliders with drain holes in the fabric always to the right of the rib. I guess this was a "left wing low" glider!

But, yes, to Hank's advice. Add a small hole where appropriate. And quarter inch sounds about right to me, too.