lexan thickness

deniseO30 · #1 (**permalink**) 02-20-2009

I found a supplier that has smoked lexan 3/16" thick. The original fixed ports for my boat were replaced with overlayed plexi by the PO. it's not a blue water boat. Is 3/16" thick enough? I think it is. but wanted some input before i buy the stuff. thanks!

resdog · #2 (**permalink**) 02-20-2009

3/16" is a bit on the thin side. It'll will likely have a good bit of distortion if it's not in a frame. I wouldn't go below 1/4". I just replaced my 5/16" (8mm) acrylic with 1/4" and it was ok because it's bolted in place. I didn't want to pop for an entire 4x8 sheet of the 5/16" so I used the 1/4" which was more readily available.

deniseO30 · #3 (**permalink**) 02-20-2009

Thanks resdog! Well, they do lay quite flat, I was thinking 1/4" also but the tell me lexan is pretty strong stuff. mine is screwed through oversized holes with washers for expansion and theres a SS lip on the top edge that makes water shed over the top. May I ask where you got your lexan?

Valiente · #4 (**permalink**) 02-20-2009

I have 1/2" fixed Lexan portlights on the pilothouse and coach house that would likely stop small arms fire, but that's supposed to be "blue water grade". I replaced 1/4" Plexiglas fixed ports on my sloop with the same 1/4" and I would hesitate to go thinner than than, even with Lexan. I would get 1/4" as others are advising.

Opening ports: tempered glass.

hellosailor · #5 (**permalink**) 02-20-2009

Denise, there's all kinds of Lexan (brand of polycarbonate) and similar materials. The supplier can tell you exactly which grade that is, and then the maker will have specs on their web site. Any polycarbonate will be better than most of what was used on "stock" boats, whether you want to go beyond what they have is another question entirely. There are some grades of polycarbonate that are specially scratch-resistant, UV-resistant, or both. Usually--that would mean ordering in whole 4'x8' sheets though, and they can get pricey.

sailingdog · #6 (**permalink**) 02-20-2009

Denise—

The thickness really depends on how strong you need and how big the ports are. Also, you really want the anti-scratch and anti-UV coated Lexan. If this stuff isn't coated, then it won't last as long.

Check with an industrial sign supply company in your area, as they may have partial sheets available at a reasonable price.

Valiente · #7 (**permalink**) 02-20-2009

This is true. Offcuts and wonky bits are common, or if you can deal with a slight flaw (say a small scratch close to the edge), you could save a bundle.

cutterorient · #8 (**permalink**) 02-22-2009

I replaced polycarbonate lenses on the three hatches on my boat and all the dorade boxes as well. 1/2 inch bronze tint was on there and thats what I used to replace it. Could I have gone thinner? Maybe. But everytime I am out in something that is really rough I never think about the hundred bucks I didn't spend. Are those lenses strong enough? It never enters my mind.

Trimmer · #9 (**permalink**) 02-22-2009

I couldn't buck up for Lexan , so I used 3/8 Plexiglass. It's been a few seasons now and It's in great shape! I found some great gasket material at (Mcmaster-Carr) on the net.

resdog · #10 (**permalink**) 02-23-2009

Quote:

Originally Posted by deniseO30

Thanks resdog! Well, they do lay quite flat, I was thinking 1/4" also but the tell me lexan is pretty strong stuff. mine is screwed through oversized holes with washers for expansion and theres a SS lip on the top edge that makes water shed over the top. May I ask where you got your lexan?

I used tinted acrylic. For my use there was no reason to go with Lexan (polycarbonate). We use a supplier called Cope Plastics. They have offices all over the US.