Plexiglass For Port Lights

[Noreastern]

In a perfect world it scratch resistant, strong as steel, affordable and would not "cloud" after years of UV ex-poser.

Back to the real world it seems like everything is a compromise. Wondering if anyone here has replaced their port lights and their preference for material.

Pictures are of old 3/8" plexiglass and cabin cut out.

Appreciate any thought as always.

Brian

[malbert73]

Tempered glass. I finally did this for about the same sized ports. Amazing difference! No scratching, etc. should be plenty strong at same thickness. I found a local glass place (non marine) that cut and smoothed edges for 50 per pane.

[endoftheroad]

Wouldn't you actually be using Lexan?

[mikereed100]

Originally Posted by Noreastern

In a perfect world it scratch resistant, strong as steel, affordable and would not "cloud" after years of UV ex-poser.

Back to the real world it seems like everything is a compromise.

Acrylic (Plexiglass) should not cloud, though it may develop crazing which can be lessened by annealing the material after it is cut and drilled. It is prone to scratching and is affected by some cleaners and solvents. Plenty strong and, with proper care, should last the life of the boat.

Polycarbonate (Lexan) will cloud with time. Very impact resistant. Can be had with coatings that will protect from scratching and UV damage.

Tempered glass will not cloud, is very resistant to scratching, will not craze and is impervious to most solvents. Also has a low coefficient of thermal expansion so less prone to leaking over time. It would be my choice for portlight replacement.

[mitiempo]

As long as the lens is not expected to take a curve laminated glass is the best choice. If a curve is required cast acrylic (Plexiglas) is the better choice. It is more scratch resistant than polycarbonate (Lexan) and will not craze near as quickly. In a reasonable thickness strength is not an issue with either. All major hatch manufacturers - Lewmar, Goiot, etc - use Plexiglas. Only Bomar uses Lexan on some of their products.

Good information here at Select Plastics, the largest hatch rebuilder in the world.
Select Plastics, LLC - Connecticut's Best Custom Fabricated Plastics and Marine Hatch Repair

[bletso]

I've tried the plastic bit. I ended up in the end with laminated glass for the port lights and 3/8 tempered glass for the skylights. Tempered glass is expensive as they have to cut it and then heat treat it. ($35 for 7 pcs 12 X 12 and $40 ea for the laminated cut shapes about 12 X 18)