Acrylic (plexiglass) is the prefered material--this is what hatches
are made from. Polycarbonate (lexan) is stronger against impact but
scratches too easily and quickly looks very dull. That said, Acrylic
needs to be cut and drilled carefully to prevent micro-cracking.
Tap Plastics has done a very nice job making windows for me on
several occassions, and they aren't too expensive. They have a
variety of colors available (I like "bronze", but folks have used all
different colors). It is best if you can take them the old windows
and have them cut the shape, add a bevel, and drill the holes. Be
specific when asking for bevels, edge polishing, drilling, etc. Holes
should be drilled slightly oversize to account for
expansion/shrinking/movement.
The last set I had made were 1/4" bronze acrylic. It was about $150
for parts and labor to have Tap cut, bevel, drill, and polish them
(2006). They look great.
I have no experience with butyl tape, but it is getting great reviews
for mounting all types of marine hardware. I just acquired some and
will start trying it out. The butyl tape I've seen is grey or black,
and may not look as good as a white or clear sealant.
Polysulfide--great for mounting most hardware--will attack many
plastics and shouldn't be used to mount acrylic (or polycarbonate)
windows. Polyeurethane (5200) is too agressive for sealing windows
(could be very hard to remove in the future). Silicone isn't
generally considered strong enough for sealing windows and also can
lead to problems with future paint jobs. That said, the 25 year old
windows in my Express 37 are still leak free from their original
silicone installation.
LifeSeal (blend of silicone & polyeurethane) is promoted as a good
caulk for acrylic windows.
Also: don't tighten the screws too much--you can easily crack the new
windows (you can guess how I know this).
--brendan
:: I see a lot of people have had to replace their windows
:: on the boats.
::
:: What is the preferred material (lexan or plexiglass) and
:: what degree of tint have people been using? My are old
:: and faded pretty bad.
::
:: What are people using as a sealant for the windows? I
:: was thinking butyl tape but just checking.
