Need help with window replacement

JamesG161 · Apr 30, 2016

Sailm8 said:
It is way too big to fit in a home oven to bend it.

You might place the window on plywood and draw out the expected curve, clamp the ends in a stress and use a heat gun in a "spray paint" like motion to warm the glass and let it bend gently.
Or...
Take it to a glass shop and let them fix it.
Jim...

woodster · Apr 30, 2016

if you can shape it to the boat with out breaking it the Dow 795 will hold it if you tape in place and let it alone for a few days...mine had slight curves in the fit up and i set the new ones in the opening and taped them in places...bake sure you get 1/8 or better thickness on the Dow between the glass and the boat surface even if you have to put small spacers/shims in the path of the Dow ...just make sure you have enough in the joint to get the proper thickness of the sealant......

do it on a hot sunny day and let the glass warm up to help you shape it ...you might even dry fit it to the boat and let it warm up that way or use a heat gun to accomplish this ...just don't burn the glass...about 125 degrees should do it

Ralph Johnstone · Apr 30, 2016

Sailm8 said:
The piece is flat and not curved like the original.

Depends on the curve. I don't know the age of your boat but for my 1999 H-310, the front hatchlight is only slightly bent. The factory installed flat acrylic and then held them in place with black painted SS screws. You can't see them unless you're close to the boat.

Once the 795 is cured, you could remove the screws if not to your liking.

As a matter of fact, that's how Hunter installed all of the other hatch and portlights but in those cases they did remove all the screws and fill the holes with 795 so that the small holes are all but invisible.

Someone recently posted a youtube video (here on SBO) on using 3M VHB tape which of course, now that I want it I can't find it. It shows a method for using both 3M VHB and 795 which appears to be near bulletproof.

JamesG161 · Apr 30, 2016

woodster said:
do it on a hot sunny day and let the glass warm up to help you shape it ...you might even dry fit it to the boat and let it warm up that way or use a heat gun to accomplish this .

That is a better idea to ease the glass shape with a gentle heat gun assist.

Just loosely insert the screws and as the middle of glass warms, tighten down the screws bit by bit. You have to be ready and quick since 795 can cure fast. Keep your heat gun away form the 795 edges work on middle 70%.
Jim...

Brian S · May 2, 2016

Here is the Sail magazine article on how to replace fixed portlights using 3M VHB acrylic double sided foam tape and Dow Corning 795. For those that originally had screw fasteners through the plexi, they only serve to hold the plexi in place as the 795 cures. The VHB tape should be plenty for the mechanical hold, the 795 for the seal. The article is very specific as to VHB thickness to accommodate the differing thermal expansion rates of the fiberglass and plexi. Also note the painting of the pleix where it overlaps the white gelcoat, to make a nice, uniform, dark window appearance. I have seen a boat that didn't do this, and all you see is a light surround around the dark window hole, and squiggles of the black 795 used to adhere. Looks like @$$. This particular boat had the plexi drilled and held in place with screw fastener the way the factory originally did it. I use VHB on my boat, and I love the clean look without fasteners.

http://www.sailmagazine.com/diy/ask-sail/replacing-fixed-portlights/

Need help with window replacement

Sailm8

.

JamesG161

SBO Weather and Forecasting Forum Jim & John

woodster

.

Ralph Johnstone

.

JamesG161

SBO Weather and Forecasting Forum Jim & John

Brian S

.