Pachuca Circumnavigation: Re fitting a leaky skylight

Sunday, June 23, 2019

Re fitting a leaky skylight

The first serious rain in months revealed that the skylight was leaking. At first Bruce thought that the solution would be a simple job of sealing the mitered corners of the teak frame with Epiglue, but that was not to be. We were forced to take the entire system apart.

The job of installing the skylight while I was in the U.S.A. had been entrusted to a man of many years experience who should have known better and will remain nameless. He had done a slap dash job with Sikaflex sealant. The Sikaflex was the incorrect material and was not sticking to the metal frame, providing one vector for the leak. A second vector was the mitered corners mentioned above. The third vector was around the six screws holding down the metal frame that had been fixed with no sealant. Worse,we found that the edge of the thru deck opening had not been properly filled, allowing water to seep into the balsa core of the deck between the layers of fiberglass which would have eventually led to serious damage.

After over an hour of patient work we managed to work through the sticky Sikaflex and remove the entire skylight. Then we cleaned the the entire system with acetone and some sanding.

Then Bruce got to work at what he excels at. He sealed the edges of the thru-deck opening with Epiglue, applied with a syringe and finished off with his finger, rendering the gap between the two layers of fiberglass now impervious to water. The Epiglue dried overnight and the next day Bruce appeared with a carefully selected "neutral" silicone sealant that will stick to metal as well as the usual materials. He used the sealant liberally then inserted the screws with plenty of sealant then screwed the metal frame down as we watched the sealant ooze out under the pressure. Some of the sealant oozed into the perimeter of the prism but that could not be helped and in any case was barely noticeable because the sealant unlike the Sikaflex is translucent. The result was "bullet proof" as they say, and I will confirm the outcome when I return to the boat today after two days of at times heavy rain.

I estimate that the initial sloppy job of installing the skylight would have taken one hour tops, and it took Bruce and myself at least four hours spread over two days to redo the work correctly.