Fly bridge wind deflector material

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Constellation1

Senior Member
Joined
Apr 18, 2021
Messages
144
Vessel Name
Constellation
Vessel Make
North Pacific 43
The clear wind deflector that surrounds the front of my fly bridge is cracked and crazed from years of UV exposure. Does anyone know the best material to replace this with? A light plexiglass perhaps? Some panels will have bends, but nothing extreme. I did check with the manufacturer, but they are all custom made, so I will need to use the existing panels as templates and new pieces fabricated. Let me know if you have taken on such a project successfully.
 
I did mine and used Lexan. Made cutting and bending easier but it crazed and clouded again in just a few years.

I would suggest plexiglass instead, but if you do it yourself, I have found often it cracks when cutting, drilling or working it so with its cost, I would let a shop do the cutting as a minimum.
 
I did mine and used Lexan. Made cutting and bending easier but it crazed and clouded again in just a few years.

I would suggest plexiglass instead, but if you do it yourself, I have found often it cracks when cutting, drilling or working it so with its cost, I would let a shop do the cutting as a minimum.

Thank you sir. I know a guy with a sister ship to mine, one year older. He has kept his covered with sunbrella since new, and they look new. I will look for a local shop to help me with this.
 
I did mine years ago, using a local shop. The old ones were used as templates, a little heat helped get the curvature right, new colour made the boat look so much newer, as the old had faded to purple in under 15 years. So far the bronze colour hasn't changed, in over 25 yrs. Yes, they are plexiglass and stand up well to UV.
 
Your choices of material is either Acrylic or Polycarbonate.

Polycarbonate is not UV stable (such as Psneeld’s experience ). It is very flexible and strong. Cracking is rarely a problem with polycarbonate however it scratches easy.

Acrylic is the most common choice for Venturi windows. Great color options, UV stable, dose not scratch easily. However, acrylic is not flexible. This problem is often solved whit a heat gun. With the right amount of heat you can reshape acrylic. Another larger issue with Acrylic is thermal expansion. All anchor point holes need to be significantly over sized to account for the thermal expansion. This part is often gotten wrong and results in traveling cracks that start at the screw holes.

Despite Acrylics disadvantages it has always been my choice for Venturi windows.
 
When you mount, over size the holes in the acrylic and use rubber grommets to allow for expansion and help prevent cracking.
 
Polycarbonate (Lexan and other brand names) can be purchased with a tough anti-scratch and UV coating. I used it to replace the yellowed and cracked acrylic that was original to the boat. I've also used it for the hail shields I made to protect the glass skylites on our house (Texas). The original plain Lexan on the skylights yellowed around year eight. The UV protected Lexan has been installed for about the same length of time and is like new. Same for the boat. Costs more than acrylic, but doesn't crack....easy to work with.
 
I removed my crazed purple/pink faded deflector and took it to TAP Plastics. It just barely fit crosswise on a 4x8' sheet of bronze Chemcast cast acrylic (Plexiglass). They used the old as a template, including drilling the holes and tapering the bottom edge (which I was not expecting). Fit took some time. Probably easiest to remove the supports, attach them to the plastic sheet, then reattach the supports (which is not what I did). Also best to have two people (also not what I did). Came to about $350 and I have lots of scrap for other projects. My boat is a pocket trawler and 4x8 was barely big enough. I don't know what the upcharge would be for a 4x12 piece.
 
Thank you everyone, this is exactly the information I was hoping to get.
 
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