Marykate® On & Off Gel
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Marykate® On & Off
Unique gel formula clings to
the surface to remove stubborn
scum lines and rust stains!
The #1 Hull Cleaner and
Strongest Formula Available!
paste. Don’t be surprised to discover that the
corner radii are crude or inaccurate. You can
improve them with the same epoxy paste.
Fair your filled holes and corner adjustments and you should be ready to install the
Your specific installation should be guided
by the instructions provided by the supplier
of your new windows, so here you’re going
to find only supplemental guidance. Many
modern portlights are sealed by a rubber
gasket under the outside flange and clamped
in place by screws through the inside flange.
If the gasket has a seam, place it at the bottom of the window. The primary concern for
gasket-sealed portlights is to make sure the
mounting surface is flat. When you dry-fit
the window (without the gasket), any gap
around the perimeter of the flange must
be less than 1/16-inch. You also want the
window to slide into the opening without
binding. Hole clearance all around of about
1/16-inch is ideal. Paying attention to these
two requirements, follow the manufacturer’s
instruction for installation.
Some manufacturers will instruct you to
seat the outside flange onto a bed of marine
sealant, either to seal, or to bond, or both.
You still need a flat mounting surface and a
slip fit. For mechanically fastened portlights,
the best bedding choice is butyl tape, a solid
sealant that will not be ejected when you
compress the flange against the boat.
Portlights to be bonded in place require
the adhesive strength of a curing liquid sealant. To avoid squeezing out most of the sealant when you clamp or press the window in
place, glue small spacers to the underside of
the flange, one at each corner and additional
ones as necessary to keep the span between
them under 10 inches. Spacers should be
1/8-inch thick and perhaps 1/4-inch across,
cut from any plastic or hard rubber and fixed
in place with the sealant you’re using to
bed the flange.
Just before applying the sealant, always
Now that you’ve got your portlights
replaced, see this article online for
Don Casey’s tips on how to keep your
vinyl and acrylic windows sparkling,
caulk and clean
Remove the interior
serving as spacers.
Apply caulk to
the back side of
Tape the face of
the exterior trim.