Re: Can I eliminate hatch

Posted by Laszlo on Sep 16, 2007


Drain/ventilation plugs can go in the interior bulkhead, rather than as pictured in Ron's reply.

On the other hand, I haven't seen any evidence for actually needing drain/ventilation plugs, at least not in the family fleet. We have a 16LT and a non-CLC boat, both of which are S&G okoume, bith of which have large sealed compartments, neither of which have drain/ventilation plugs.

The compartments are epoxy sealed inside, glassed outside. Short of jamming an icepick into them, I don't see how any water could get inside to need draining or ventilation.

Some people have expressed a concern about thermal cycles (trapped air expanding and contracting as the temperature changes) causing fatigue cracks, but I don't buy that either. First, I keep my boats in the garage, out of the direct sun, so the daily cycles are less extreme. Second, I use my boats on Earth, not in outer space, so there's air pressure inside and out and they tend to mostly balance. Third, if you dig out Boyle's Law & Charles' Law for the behavior of gas, the total imbalance in pressure is less than 2 psi over a summer to winter temperature range (solution left as an exercise for the reader). This is roughly the same change in pressure as caused by putting your boat in the water and paddling it at a moderate speed (see Designing Power and Sail, by Arthur Edmunds). So I can't get excited over the pressure changes.

However you decide to do it, no hatches are just fine for the Chessies.


In Response to: Can I eliminate hatches by chris on Sep 15, 2007