Window caulking
Some Senoritas have stylish metal profile frames for the windows. Ours had plexi sheets attached with sheet metal screws and silicone. Starting on the first rainy day of the first summer's first trip, they leaked. Replacing the silicone and tightening the screws helped - for a month.
The problem has two sources: the thermal expansion of the plexi sheet on a sunny summer day is much more than that of the glass fiber hull to which it is attached. The thin layer of silicone between the plexi and hull cannot stretch enough but lets go, opening a path for the leak. Secondly, silicone looses its flexing properties because of the uv radiation.
I finally (hmm; 4 summers) got fed up with the dripping water and replaced the silicone /sheet metal screw attachment at both windows with a 5 mm thick layer of Sikaflex caulking, specifically designed for marine windows. The steps to do this are below:
Remove the window panes and clean the gasket surfaces from all residuals of silicone at the hull and plexi.
Attach a narrow, appr 5 mm thick strip of rubber strip seal close around each of the window holes to be covered by the plexi. The purpose of the seal is to keep the plexi 5 mm apart from the hull and to prevent the gasket cement from creeping in before it has set. I used a roll of self-attaching rubber strip seal for doors and windows from the local hardware store. The seal helps to form a 30..40 mm wide strip of Sikaflex around the perimeter of the window pane.
Use masking tape and paper or plastic as protection around the perimeter of each window, to prevent the gasket cement from spreading and to make a nice border for it. (Sikaflex easily makes a mess and is hard to clean)
Put the plexi glass in place, using only a few (1/4..1/5) of the screws as guides. Tighten the screws only enough that the rubber strip seal around the window holes touches the plexi all over; about 5 mm gap should remain between the plexi and the hull. You likely will need to get a handful of new screws that are 5 mm longer than the original ones.
Now, inject Sikaflex into the gap between the plexi and the hull, to completely fill the space from the strip seals around the window holes to the outer rim of the plexi panes, around the whole window pane. See that the few sheet metal screws in the gap are also surrounded with the cement.
Smoothen the outside surface around the window perimeter with the tip of your finger. Clean all excess cement at once from the window and from where ever else it may have found its way.
Open the sheet metal screws, one at a time carefully a few turns and then screw them back: this will have some cement enter the screw holes to seal them. Now you may remove the protective tape from around the windows and clean up where needed.
Sikaflex is curing at a rate of several mm a day so that the new gasket will be fully cured within a few days. Before that, do not bump on the window pane, so as to not to purge the uncured cement into wrong places.
