Fixing glass windows into steel pilothouse

[stillbuilding]

I am installing 15mm glass windows in the pilothouse of my steel yacht. I have used ss angle to provide a seat with adequate space for sealant and will have a ss cover-strip but i am considering options to hold the glass in place. The builders want to simply drill app

[stillbuilding]

Originally Posted by stillbuilding

I am installing 15mm glass windows in the pilothouse of my steel yacht. I have used ss angle to provide a seat with adequate space for sealant and will have a ss cover-strip but i am considering options to hold the glass in place. The builders want to simply drill app

Apologies - bloody I phone.
The builders want to simply drill appropriate holes and bolt the cover strip and glass in place but i worry about corrosion and thinking that maybe just a top notch sealant might be adequate? Or maybe weld in some threaded studs instead of using bolts? Or some weld-on studs with clips outside to hold the cover strip in place. Am i worrying about nothing?

[Panope]

I did the same sort of thing with my aluminum pilot house. I too did not want fasteners and the resultant potential for corrosion. Glass is bedded with 5200 into an aluminum flange from the outside of boat (a wave or other force from OUTSIDE of the boat cannot push glass inboard). An aluminum "bezel" (cover strip) was then bedded with more 5200 to keep the glass from being pushed OUT from the INSIDE. This is very strong, but note that my glass is recessed about one inch - this allows the bezel's 5200 to be acting in sheer. If your glass/cover strips are placed on the surface of your house then I believe the bedding compound alone is not enough. I found that 5200 does not stick very well to smooth glass. Next time I would sand or sand blast the contact area of the glass prior to bedding.

The Bezels are the parts in light green primer.

Steve

[S/V Alchemy]

I think that bezel idea is sound, but I also think you can just have them clipped inside an SS or even an aluminum frame (electrically isolated with rubber or sealant). The key is to weld studs capable of having some kind of storm shutter. Only the center window on the pilothouse needs to open, and it can be made of tempered glass dogged down with levers onto soft rubber (EPDM) seals like the hatches.

My pilot house has 1/2 inch Lexan through-bolted on the sides; only the forward trio of windows are glass. There's no leakage or corrosion around the Lexan, but it is definitely a valid concern.

[Andrew Troup]

I sailed for many years on a very well built 40' sailboat whose glazing was flush-bedded into recesses in the coachroof sides with a 'top notch sealant'

Then a stripe of black paint was used to prevent UV from reaching the sealant.

I felt a bit queasy about this. Sure, seas cannot push the window in, but how about something heavy like a battery or a cooker or a person's foot landing on it from inside, neatly popping the panel out?

Anyway, be that as it may, last but one offshore trip saw us doing emergency repairs, drilling through into the coachroof and fitting screws, because the sealant had finally let go, presumably from the tension of the slightly curved lexan panels trying to pull straight.

By then I think the sealant was about nine years old.

[stillbuilding]

Mine are inset 20mm - allows for bedding of glass and the cover strip so 5200 may be good.
Thanks for the pics and comments

[stillbuilding]

Not very good pics but you can see the ss "shelf" for the glass. Just bit of plastic for the rain at present.

[aclmck]

Hi Stillbuilding,

i may be wrong as i know little about 5200 (i think a 3m product) but most if not all sealants required to adhere as well as form a gasket and seal will not adhere to stainless Steel or cello tape so to be sure get hold of the data sheets, mostly they say to prime metals which most suppliers refer to as steel or alloy of some form to provide a key to the metal.(don't ask how i know about the adhering to stainless)

the Glass ,lexan or poly used in windows works best if it is primed, i normally use a sika primer for this and works well to adhere to glass in underwater panels

so just check the info if you use any sealant you expect to adhere to any surface and if in doubt send the supplier an email.

[stillbuilding]

Originally Posted by aclmck

Hi Stillbuilding,

i may be wrong as i know little about 5200 (i think a 3m product) but most if not all sealants required to adhere as well as form a gasket and seal will not adhere to stainless Steel or cello tape so to be sure get hold of the data sheets, mostly they say to prime metals which most suppliers refer to as steel or alloy of some form to provide a key to the metal.(don't ask how i know about the adhering to stainless)

the Glass ,lexan or poly used in windows works best if it is primed, i normally use a sika primer for this and works well to adhere to glass in underwater panels

so just check the info if you use any sealant you expect to adhere to any surface and if in doubt send the supplier an email.

Good point. Will check.

[boasun]

There is double channel gasket material that is water tight and locks the window in place. Used it several times on commercial vessels

[mikereed100]

15mm? Dayam!
You have several good options for bonding the glass to the wheelhouse. Dow 795, Sika 295 uv (must use primer), GM VHB tape with glass primer to name a few.
Dow 795 is an architectural silicone adhesive that is used to hold windows in skyscrapers.http://www1.dowcorning.com/DataFiles...c8802a267c.pdf
Sika 295 uv is a urethane adhesive that is often used with acrylic on boats but can be used with glass as well.sika 295 uv data sheet - Google Search
GM VHB tape is an acrylic tape used like Dow 795 in the building industry.
With any of these be sure to use enough material to allow for expansion and contraction, although with glass this should not be a big problem.
I would caution against 5200. While it may work fine, glazing is not it's intended purpose. Horses for courses and all that.

[Cheechako]

wow...5/8" thick glass?

[marshmat]

3M 5200 is not a glazing adhesive. Sikasil SG, or Dow Corning 895 and 995, are the best choices at present for gluing glass to a frame without using a pressure plate or cap. When you're building a bank tower and you need the 4'x6' windows on the 60th floor to survive a hundred-year hurricane, these are the sealants you use. The glass can be blown to pieces and the frame bent into a pretzel, they still won't let go.

Gluing glass in this fashion is a bit tricky. The surface must be scrupulously clean- handle with clean gloves, scrub twice with alcohol and clean cloths, etc. (the oil from a fingerprint will weaken the bond). Prime the surfaces correctly, if specified. And, of course, follow every detail of the vendor's instruction sheet to the letter.

Structural glazing sealants form a chemical bond with the glass. No sanding or roughening is required.