Last December, when blogging about our maintenance schedule for this winter, I wrote that most probably new things will come up, once we start digging deeper.
Unfortunately, this turned out to be too true — we recently found out that there is water inside DD’s keel! However, this unpleasant finding was not totally unexpected, since last spring, I noticed some condensation on certain areas on the keel when the air temperature was close to zero. I noted down those areas, but I did not want to speculate it too much then: further investigation would have involved drilling holes into the keel, since the moisture meter is not reliable in the keel area. As the sailing season was just round the corner, I decided to leave further investigation for this winter.
The reason for the mysterious condensation became more obvious, when I took a closer look of the bilge: the back corner was looking suspicious since it stayed wet, even if I had dried it just a few days earlier. Furthermore, I found out that a part of the topcoat was missing in the back corner of the bilge. I am not sure if this defect has been there since new, but it was really difficult to spot, since the bilge pump hose was blocking the vision. Only when I lifted the hose, I could get a proper view of the whole bilge sump. Over the years, there has probably been some bilge water standing there. This is the negative side of having a very deep bilge: the bottom of the sump is difficult to reach and the pump, or even the drain plug, does not dry the far end of the bilge. The water in the bilge has probably, over a very long period of time, seeped into the keel.
At first, Jarkko set up a vet vacuum machine to the holes to get the most of the water out. After this was completed, he set up his HotVac-pads on the keel. To my knowledge, the HotVac Hull Cure is the most advanced method of drying up fiberglass laminate and it is used widely in osmosis repairs for example. The HotVac pad applies controlled, uniform heat and high vacuum to the affected area. This treatment should also get DD’s keel completely dry. After the treatment, the holes will be filled and re-laminated, and the bilge re-coated. I will report about the progress of this repair later in the spring.