I'm in the process of stripping a Hurley 20, but upon taking out the floorboards, I noticed that the bilges contained some water, and that the bilge area was divided into small segments by ribs about five inches high. I wonder whether there should be holes in these ribs to ensure that the water can drain to a place where the bilge pump can reach it, and whether I should drill holes in the floorboards and bunks to enable the moisture in the bilges to evaporate?
Dan Dickison responds:
Most boats do have holes in their athwartship ribs so that water can drain to a central location or sump and then be expedited out by a bilge pump. The thing to remember when you're drilling limber holes in frames is that you want to seal the inside of the holes so that water doesn't penetrate the core of the ribs.
I recommend you drill the holes slightly larger than a piece of tubing that you plan to insert into them. (PVC pipe can work for this application.). Then apply a marine sealant to them, and make sure the sealant coats the interior (you can use a small wooden dowel to do this). Then insert the tubing, making sure that it protrudes slightly on each side of the rib so that you can get a secure seal between it and the rib with the marine sealant.
Regarding holes in the floorboards and bunks for evaporation, that really shouldn't be necessary unless the floorboards and bunks are tightly sealed over the area below them, which I doubt is the case. You only need minor openings for evaporation to occur, and the existing cracks between the floorboards and the bunks should take care of that. For further detail on projects like this, you might want to refer to Don Casey's "This Old Boat." It's a very useful resource for a wide variety of boat projects.