The following was prepared by Lewmar in 2008 to address known issues with the original Old Standard Opening Portlight.
The Old Standard Portlight was in production from 1980 to 1998. Some older units have developed leaks through the frame joints. The water appears on the inside of the portlight near the handle. There is an unused fastening hole in the frame through which the water enters the boat.
The water enters the portlights through the joints in the outside frame and follows a hollow in the extruded frame until it reaches the hole near the handle where it can escape. To fix the leak it is not necessary to remove the portlight from the boat.
With the portlight in place remove as much of the (rubber) gasket material from the outside frame as possible and replace with silicone sealant.
If the boat is subject to temperatures below 0ºC (freezing) do not block up the hole on the inside of the window near the handle as this could trap water in the frame.
It is also possible for leaks to occur through the handle. If this is the case, remove the cap and the screw to release the handle from the acrylic. The O-ring under the mushroom on the outside of the window can be replaced. The O-ring is a standard size and not available from Lewmar as a spare (EBW - we do stock these). The replacement O-ring should be lubricated with a (EBW - very) small quantity of silicone grease before refitting.