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One of None
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Discussion Starter · #1 ·
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!
 

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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.
 

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One of None
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Discussion Starter · #3 ·
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?
 

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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.
 

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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.
 

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Telstar 28
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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.
 

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polycarbonate

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.
 

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Junior Mumbler
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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.
 

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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.
 

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Trimmer- which Gasket sealant did you select from Mcmaster-Carr?
 

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Junior Mumbler
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G.W. I used neoprene rubber. I think it was 3/16 thick. I bought about 2' x 4' and made my own gasket, no sealant of any kind. I drilled holes through the plexi just a little larger then the screws and used a washer w/ a built in rubber gasket (from ace hdwr).No leaks! Btw Mcmaster Carr has so much stuff I recall I had to call for guidence.
 

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Telstar 28
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One thing to remember. If you have to drill holes in plexiglass or polycarbonate, you really want to counter sink the holes on both sides so they don't become a starting point for a stress crack.
 

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One of None
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Discussion Starter · #14 ·
I think the rubber gasket makes more sense then various types of caulk, mostly because the white shows through the plexi or lexan when it's overlayed like it is on mine. Painting it black was a thought also. Darn shame the original fixed port frames are gone. (one has to wonder what PO's were ever thinking)
 

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I think the rubber gasket makes more sense then various types of caulk, mostly because the white shows through the plexi or lexan when it's overlayed like it is on mine. Painting it black was a thought also. Darn shame the original fixed port frames are gone. (one has to wonder what PO's were ever thinking)
What are you talking about? The boats look way better once those frames are gone...:)
 

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The gasket approach is also more in line with what the various maufacturer's suggest on their installation data sheets. More time and effort than just gluing things together, so less likely to be found on a stock boat.
 

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I have not tried it but I would think that the butyl rubber gasket strips would work well. It stays soft and therefore gives as needed and still seals.

Gary
 

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The gasket strips sound like a good idea. I am just about to replace 3 large ports with Lexan (AR abrasion resistant) and they have a 2.5 inch thick SS frame inside and out so the gasket will be covered. I had planned on using a goopy sealant, but after reading this thread I am considering other ideas!
 

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Denise

If the existiing lexan is in good shape and you want to change to smoked 4 esthetic reasons, why not just overlay the new onto the old. That way even one eighth would be thick enough.
 

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Junior Mumbler
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When I did mine I used sheet neoprene. That way I had a seemless gasket. I installed the full sheet, and then carefully trimmed the perimeter with a razor knife. Inside too. The usual trick is to use the external frames inside the cabin on the oposite port. Mine were plastic and broke apart removing them. I made some teak frames for inside the cabin. I'm a little impatient and drilled holes straight through the plexi .Oops no double countersink. As yet, no stress cracks either.( but I do have some stress):eek:
This project took a looong time. Buy beer!;)
 
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