Really, why not automotive quality glass?

[Dsanduril]

Originally Posted by blu3534

...For people in colder areas I wonder what they do with cold windows (and frames)? Currently, as an experiment, I use bubble cushioning wrap over the glass --> it helps but one gets depressive . Ok, I exagerate, but I do miss to look outside. On the other hand if one does nothing and, say, the whole hull is wrapped with Armaflex, the windows are the one top source of loss of heat. (Sorry, maybe a bit of topic drift, automotive glass is not isolated afaik).

Contributing to your thread drift, if your interior frames are suitable we installed 3M Clear Window Insulating Film. Stretched tight it is crystal clear, provides a dead-air space between the glazing and the interior frame. Ours has been on the windows about 18 months now, still going strong.

Now back to glass vs. plastic.

[CarinaPDX]

I'm a bit baffled by this thread: glass is used a lot on boats and is far more durable than the plastic alternatives. My overhead bronze hatches are more than 40 years old and have the original (laminated?) glass in them, clear as a bell. The glass is protected by bronze bars. All of my portlights have laminated glass in them. When I made my hard dodger I used a van windshield, turned upside down, tilted aft a bit, and the ends cut off. It looks and works great. Since it is laminated I'm not worried about it if it fails. The side windows are acrylic and will need replacing in a few years (the dodger is about 15 years old). I am considering replacing them with glass. To me the question is "why plastic?".

Greg

[jacktheflyer]

I have laminated glass on my Fusion40. Most panels have delaminated around the edges after 10yrs due I'm told to an incompatible adhesive sealant. To replace them now will coast about AU$8000 for a set of 8 windows if I can find someone to mould them. Have had quotes of $25,000 for one window.

[Djarraluda]

Originally Posted by CarinaPDX

I'm a bit baffled by this thread: glass is used a lot on boats and is far more durable than the plastic alternatives. My overhead bronze hatches are more than 40 years old and have the original (laminated?) glass in them, clear as a bell. The glass is protected by bronze bars. All of my portlights have laminated glass in them. When I made my hard dodger I used a van windshield, turned upside down, tilted aft a bit, and the ends cut off. It looks and works great. Since it is laminated I'm not worried about it if it fails. The side windows are acrylic and will need replacing in a few years (the dodger is about 15 years old). I am considering replacing them with glass. To me the question is "why plastic?".

Greg

Just a note of warning with Laminated. It is manufactured from layers (glass/plastic/glass)so especially if you trim it to size and do not seal the edges it can be susceptible to penetration of oils. Silicone is our known enemy on a boat, but glaziers seem to love it at times. I have seen the silicone oil migrate through the centre of laminated glass when it has been bedded on silicone.
Only use butyl mastic and ensure the edges are fully covered.
Yes I know it means inner and outer frames are required rather than just a lap construction and adhesive but you don't want to stick the glass on and then over next couple of years find this creeping opaqueness spread through the window.
Roger

[wrwakefield]

Our Nauticat 43 staysail ketch [S&S design launched in 1983] has all the original factory tempered glass [and it all looks like new] in every clear opening except the sliding companionway hatch. [All ports- fixed and opening; all hatches; the pilothouse windshield and windows.] Everything is single pane [i.e., not-insulated.] All other Nauticat models I've seen also had glass, but there may be exceptions I'm unaware of.

As mentioned by Dsanduril for cooler climates, a simple interior application of shrink-to-fit clear window covering [3M seems to be best from our experience] mitigates cold conduction, and lasts for several seasons if not abused.

I have also seen a more permanent solution [10 years old and counting] using Makralon attached to the window frame with 3M VHB tape. [Makralon is a polycarbonate with UV inhibitors that lasts many years if properly cared for... We used it in our latest dodger and are very pleased with the optical clarity. It may be worth noting that 40 mil thick Makrolon can be rolled; 60+ mil cannot.]

On our boat, the fixed windshields and side windows of the pilothouse are sandwiched between two 1-piece aluminum frames [inside and outside that bolt together.]

A sistership that transited from the South Pacific to Alaska this year hit some weather that had them taking breaking seas over the bow for a couple of days. They reported no issues with any of the ports, hatches, or windows/windshields...

If you are wondering about toughness, it is worth noting that most automobiles use tempered glass everywhere except the windshield [which is typically laminated glass...]

In case this is helpful.

Cheers! Bill

[CarinaPDX]

Originally Posted by Djarraluda

Just a note of warning with Laminated. It is manufactured from layers (glass/plastic/glass)so especially if you trim it to size and do not seal the edges it can be susceptible to penetration of oils. Silicone is our known enemy on a boat, but glaziers seem to love it at times. I have seen the silicone oil migrate through the centre of laminated glass when it has been bedded on silicone.
Only use butyl mastic and ensure the edges are fully covered.
Yes I know it means inner and outer frames are required rather than just a lap construction and adhesive but you don't want to stick the glass on and then over next couple of years find this creeping opaqueness spread through the window.
Roger

It isn't just oil that one must protect against. The reason I know that my portlights are laminated glass is that I had to replace the glass in them 30 years ago. A friend of mine who had a small company making specialized commercial cleaning products gave me some of his (non-fluoric acid) window cleaner to use. It cleaned the glass superbly. I hosed them off thoroughly afterwards and thought that was a good job. Then they started to cloud from the edges inward. It turns out that the edges of the glass were not sealed, and of course the exterior rinse didn't remove the cleaner that had migrated into the plastic layer. Although it was only cosmetic damage I replaced them with fresh glass and a lot of Sikaflex. So yes, another vote for sealing the edges of laminated glass.

Greg

[dcarratt]

Lewmar https://www.lewmar.com/node/20221 makes plenty of different types of glass for marine applications. It will be heavy and expensive and mainly used in "high end" applications.

[Manateeman]

We have four 24” x 24” Bomar hatches which I must remove because I had one split from the hatch dog hole clear across diagonally when I stepped on it. 1/2” plastic. Bomar best “Ocean” hatch at about $1k each. Bomar told me to stuff it as the warranty is just one year. So much for plastic.
Our pilot house windows are laminated bank glass.
We researched this thoroughly and are very pleased with them.
We have stainless hurricane covers so the forward glass does not get scratched or sand blasted. We are planning to add a thin tempered glass interior pane and fill the space with argon which is easy to top off since we use it for our TIG welder.
Frosting along some edges of laminated glass is too complex a subject to get into here but new technical solutions by glass companies appear to have solved this issue. Commercial glass producers will help with the engineering.
I’m very confident in the glass we have and I intend to fabricate replacements for the plastic large hatches which clearly should not be labeled ocean.
Mark and his “pizza and LIGHT beer “ manatees

[Exile]

Originally Posted by CarinaPDX

I'm a bit baffled by this thread: glass is used a lot on boats and is far more durable than the plastic alternatives. My overhead bronze hatches are more than 40 years old and have the original (laminated?) glass in them, clear as a bell. The glass is protected by bronze bars. All of my portlights have laminated glass in them. When I made my hard dodger I used a van windshield, turned upside down, tilted aft a bit, and the ends cut off. It looks and works great. Since it is laminated I'm not worried about it if it fails. The side windows are acrylic and will need replacing in a few years (the dodger is about 15 years old). I am considering replacing them with glass. To me the question is "why plastic?".

Greg

I've been asking myself this same question for years now, and may finally get around to replacing all my portlight lenses (16!) this winter (so I can quit asking). Mine are all Bomar aluminum-framed opening ones, and all acrylic afaik. The frames all look to be in excellent condition and have never leaked, so no need to replace. The lenses, however, are predictably crazed and yellowing, and I'm tiring of trying to polish them with only partial success.

Unless cost-prohibitive, I'd prefer to replace with tempered glass and be done with it all, but since I'm limited to the same thickness as my existing acrylic ones, my primary concern is whether tempered glass would offer similar strength to what I have (probably original). One of Noelex's posts above states that the two materials are similar in that respect so maybe my concerns are for naught. Other than glass being heavier, along with possibly requiring a different type of sealant (no fasteners on mine), does anyone know if there are any other potential issues/concerns with converting from (OEM-supplied) acrylic to glass?

[LittleWing77]

Originally Posted by CarinaPDX

When I made my hard dodger I used a van windshield, turned upside down, tilted aft a bit, and the ends cut off. It looks and works great. Since it is laminated I'm not worried about it if it fails.

Hey Greg,

Would you please post a picture of your hard dodger? This sounds an amazing innovation and I'd love to see how it looks overall.

The project would make a good Good Old Boat article, by the way.

Warmly,
LittleWing77

[tkeithlu]

There is a significant difference between Lexan (polycarbonate) and Plexiglas (acrylic). Acrylic is harder and more scratch resistant, but crazes with time and can shatter. Polycarbonate is soft, scratches, but will bend double before breaking. Acrylic is much more common for ports, but if ultimate strength is more important than optical properties, go with polycarbonate.

[CarinaPDX]

Originally Posted by LittleWing77

Hey Greg,

Would you please post a picture of your hard dodger? This sounds an amazing innovation and I'd love to see how it looks overall.

The project would make a good Good Old Boat article, by the way.

Warmly,
LittleWing77

I described it with photos in this post: https://www.cruisersforum.com/forums...ml#post2249563 . Anyone doing a custom hard dodger should read the entire thread.

Greg