Dead Light / Window Replacement Project

[Extemporaneous]

And so I'll tell you my plan and hope to hear some feedback.

Right now there is Lexan installed (can't even see through it anymore). I don't have them out yet, but I know that it is VERY thin material. I know this because it is applied to the surface of my Pilot House with a Stainless Steel frame around them. The outside SS frame traps the lexan between it and the fiberglass structure. I have the interior out so I know that the lexan doesn't come through the cutout. I didn't think that the lexan was surface applied at first because when you look at them from the outside the SS frame is sitting virtually tight against the fiberglass. There is no recess in the fiberglass and so that's why I figure it's VERY thin material.
I'm going to replace with Cast Acrylic. The SS frames encroach on the opening in the fiberglass by approximately 1/2 inch. What I was planing to do is cut 1/2" plywood the shape of the openings in the fiberglass and push it out from the inside of the Pilothouse up against the exterior SS frame (there are some slight curves, perhaps 1/4" in 16"s). Once this is done, I'm going to buildup the interior of the of the fiberglass with thickened epoxy using this plywood as a screed. I then will make interior frames (not sure with what yet, any suggestions?) that match the exterior SS frames. The cast Acrylic would be sized 1/8" smaller all the way around the opening in the fiberglass. It would be installed and siliconed around the outside edge. This exterior and interior frames would then be screwed together (not through the Acrylic) clamping the Acrylic to align flush with the 1/2" fiberglass structure until the silicone is cured. After the silicone has cured, the frames (exterior and interior) would come off and then I would install something like "VLB" tape between both the exterior/interior frames and the fiberglass structure and re clamp the Acrylic.
Will this make for an acceptable Blue water installation?
Is 3/8" to 1/2" overlap (of the frames) onto the Acrylic be enough?

And another question.
Does any one know if there is one manufacture of Acrylic (Plexiglas, Perspex, Plazcryl, Acrylite, Acrylplast, Altuglas, & Lucite) that is better than the other?
And.... I read somewhere that the army or air force only uses a particular tint of bronze for seeing through. I can't find where I read this, can anyone help me out on this too?

I only want to do this once (not even once, but I have to) and so any good advice would be appreciated.

Thanks,
Extemp.

[Sunspot Baby]

Do a search for "sexy windows" there are some very good discussions of this topic already on the forum.

George

[bwalsh]

I dont really follow your description to give my opinion on the method, however I guess for the strength thing id like to see the plexi or whatever you use installed against the outside of the pilothouse so that any forces inward are opposed by the pilothouse itself. I kind of gather that you are planning to glue from the inside? When i removed mine I took off the old aluminum frames and made some new ones so I could mount from the outside for strength.

I did a couple new windows by cutting a frame out of AZEK brand Pvc trim (for houses) and dadoing out the back side for the polycarbonate to fit in, then I painted the frames with LPU and siliconed in the polycarbonate. Next i drilled and countersunk the screws from the outside, siliconed the frame and installed the whole thing on the boat. From what i could gather, Makrolon is the preferred polycarbonate for marine use. Their is some MR10 lexan or some such thing but the makrolon was easy to get off the 'net. The chief concern is the resistance to UV and only a few of the polycarbonates have a coating to resist the effects of UV.

Heres what mine looked like:

[Extemporaneous]

Originally Posted by Sunspot Baby

Do a search for "sexy windows" there are some very good discussions of this topic already on the forum.

George

If there are window threads on the site that I haven't read, there aren't many. I think my install is a bit different than any I've read about. I'm sure my description was hard to understand but I haven't made a drawing yet.
Thanks anyway.

Extemp.

[Extemporaneous]

Originally Posted by bwalsh

I dont really follow your description to give my opinion on the method, however I guess for the strength thing id like to see the plexi or whatever you use installed against the outside of the pilothouse so that any forces inward are opposed by the pilothouse itself. I kind of gather that you are planning to glue from the inside? When i removed mine I took off the old aluminum frames and made some new ones so I could mount from the outside for strength.

I did a couple new windows by cutting a frame out of AZEK brand Pvc trim (for houses) and dadoing out the back side for the polycarbonate to fit in, then I painted the frames with LPU and siliconed in the polycarbonate. Next i drilled and countersunk the screws from the outside, siliconed the frame and installed the whole thing on the boat. From what i could gather, Makrolon is the preferred polycarbonate for marine use. Their is some MR10 lexan or some such thing but the makrolon was easy to get off the 'net. The chief concern is the resistance to UV and only a few of the polycarbonates have a coating to resist the effects of UV.

Heres what mine looked like:

Very nice!
I will make a drawing which hopefully explains it better that I write.
That said, I think you may get it.
Basically the Acrylic would go right through the opening if it were not for the frame on either side. The exterior and interior frames cantilever from the fiberglass into the window opening and trapping the Acrylic.
I may have to re-think this as I do understand that they would be A LOT stronger if they were on the exterior and lapped onto the fiberglass.
I'm trying very hard to reuse my old exterior stainless steel frames which would have to have a 1/2" return (going to use 1/2" cast acrylic) welded around the perimeter of all of them in order to face mount the acrylic. I bet that would bet expensive! Perhaps I could make a 1/2" spacer out of plastic instead?

Thanks for the comments.
Extemp.