I plan to replace Lewmar Old Standard portlights with their New Standard version on my '94 Bnenteau largely because my demands in the Chesapeake are modest, the new version has been redesigned for easier maintenance to prevent leakage, but primarily because I can use the same cutouts.
The instructions for both versions state that a sealant with adhesive qualities, i.e. silicone, should be used. As a fan of Bed-it butyl tape, I'm tempted to ignore the instructions, however the Lewmars install a little differently than other portlights. Other portlights will have an inner and outer frame similar to the Lewmars, but the screws that attach the frames together go through the coachroof. On the Lewmars, the screws are inside the cutout opening and clamp the frame to the edge of the cutout. The screws do not go through the fiberglass, and there's not what you'd call lot of frame overlap.
Theoretically that means the portlight could slide vertically or horizontally, depending on how much clearance/slop there is between the installed screws and the edges of the cutout. At this point I'm in the planning stages and have not removed a portlight, so can't comment on how much slop actually exists, but I'm guessing not none. In an older HTM article, Rod stated that had bed -it existed when he installed his New Found Metals portlights, he would have used it. But in his installation the screws pass through the coachroof to lock them in place, so no chance of sliding.
Love to hear from you guys on this subject, particularly if you've replaced portlights, and especially if you have used Bed-it for the install. If not, what did you use?
The instructions for both versions state that a sealant with adhesive qualities, i.e. silicone, should be used. As a fan of Bed-it butyl tape, I'm tempted to ignore the instructions, however the Lewmars install a little differently than other portlights. Other portlights will have an inner and outer frame similar to the Lewmars, but the screws that attach the frames together go through the coachroof. On the Lewmars, the screws are inside the cutout opening and clamp the frame to the edge of the cutout. The screws do not go through the fiberglass, and there's not what you'd call lot of frame overlap.
Theoretically that means the portlight could slide vertically or horizontally, depending on how much clearance/slop there is between the installed screws and the edges of the cutout. At this point I'm in the planning stages and have not removed a portlight, so can't comment on how much slop actually exists, but I'm guessing not none. In an older HTM article, Rod stated that had bed -it existed when he installed his New Found Metals portlights, he would have used it. But in his installation the screws pass through the coachroof to lock them in place, so no chance of sliding.
Love to hear from you guys on this subject, particularly if you've replaced portlights, and especially if you have used Bed-it for the install. If not, what did you use?