Fly bridge windscreen material

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Aqualund1981

Member
Joined
Oct 28, 2018
Messages
23
Location
Essex, CT
Vessel Name
Aqualund
Vessel Make
42 Grand Banks Classic
Hey everyone. Spring is coming. Just wrote my list of maintenance items needed.
Long list.
1980 Grand Banks
Need to replace the old windscreen on flybridge.
It is clear plastic fastened with screws to the tradition wood brackets.
What is the best material?
Lexan. Polycarbonate ?.
 
It's a 'Venturi' :)

TMK Lexan is polycarbonate. I think your thinking of acrylic vs polycarbonate.

Call local fabricator. Start with the vendors the marina recommends. Try a glass shop and if they don't do it, they will likely be able to refer you as well.
 
I like polycarbonate. Less prone to crazing than acrylic.
 
Lexan is a brand of polycarbonate. the alternative is acrylic. Both can be used in this instance.

Good quality acrylic "Plexiglas" is more resistant to UV than lexan and comes in a wider range of colors. Surface is more resistant to scratching. It is a less tolerant when drilling and cutting but fairly easy to work with.
 
There is a glass shop in Mystic, Mystic Mirror and Plate Glass is the name, I think. The owner is a boater (or was a few years ago).
That would be one place I would call or visit and ask.
 
I deleted my previous post....I used Lexan and it fogged/crazed in a year...yes easier to work with against cracking...but not a great outside material in tints.

I would use Plexiglass....and be very careful with drilling, bending and mounting....look to Google/YouTube for tips on all those actions.
 
You want Acrylic, Polycarbonate is not UV stable. Plus Acrylic comes in many tints.
 
Polycarbonate is much stronger than plexiglass, it is blow resistant which plexiglass is not.
Polycarbonate can be bought in different versions.
I made double glazing myself in our boat and chose to provide both sides of the polycarbonate with a UV filter and let it harden on both sides, so you can compose the polycarbonate yourself.

Mvg,

Pascal.
 
Here is an example, plexiglass of a GEBO escape hatch, GEBO was the first escape hatch with Loyds certificate!
Plexiglass is not UV resistant, a blow with the hammer and I had many pieces.
I have now replaced it with polycarbonate.

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Mvg,

Pascal.
 
Well I never did learn the names correctly...so I still use Lexan and Plexiglass.

Lexan fogged way sooner than the plexi I had and could not be brought back with year after year of power buffing.

I used Lexan as I was afraid I would break plexi when I drilled and bent it...but you could hardly see through it after a couple years.

A flybridge venturi hardly needs to be strong or shatter resistant, but I do like to be able to see through them.
 
Aqua
Contact a couple of the plastic shops in your area.
My vote is for polycarbonate with UV coating.

I've done that and laminated glass cut with water jet, polycarbonate way less hassle, weight and cost.
 
There is a glass shop in Mystic, Mystic Mirror and Plate Glass is the name, I think. The owner is a boater (or was a few years ago).
That would be one place I would call or visit and ask.

Jay,

I have used them many times both at home and for the boat. Always very good work at a reasonable (not cheap) price.

Rob
 
Polycarbonate is very flexible and shatter proof. It is soft, scratches easily and degrades rapidly in UV. I use it for dingy windscreen because acrylic can’t stand up to the abuse a dingy wind screen receives.

Acrylic is not flexible but with heat bends can be molded into it. Acrylic is much more scratch resistant and much more resistant to UV. It comes in many colors, bronze is a favorite of the marine industry. It expands and contracts much more than glass or polycarbonate which means if you don’t properly oversize the attachment holes large cracks will occur. I use it for Venturi windows, stays clear longer and I can mold it with a heat gun.

There is no correct answer here. Pick the product whose characteristics best fits your needs.
 
An example of what is possible with polycarbonate.
The plastic frame around my two Simrad screens was torn in the corners.
These were no longer available so I made a new frame out of 10mm polycarbonate in one piece that covers the two screens.
The polycarbonate of 10mm thick is milled out to 2 mm, the edges to 1 mm without tearing!
I sawed the name Simrad out of the old frame and glued it to the new frame and sprayed everything with Motip satin gloss.
Polycarbonate is a great product and can be glued extremely strongly, it is further processed as wood and you can tap wire into it well.
Paint adheres very well to polycarbonate.
Polycarbonate is used, among other things, for airplane windows and headlights for cars.

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MVG,

Pascal.
 
Whatever you choose in the end, if you can get it with uv protection it will be worth it.
Real glass is a possibility as well. Tempered glass will last indefinitely.
 
Welcome to the fun of the internet knowledge base. There really is no right or wrong, just opinions.
 
So does plexiglass, see my earlier post.
Greeting

Pascal.

Acrylic does not live for ever. However, it will look better for a much longer period than polycarbonate. This in itself does not make it the correct choice.

Acrylic is also the choice of most porthole lens as it looks clearer for a much longer period of time. However, most offshore sailing vessels use polycarbonate for windows. It is much stronger and expands much less with temperature changes making it safer long term.

I use a UV coated polycarbonate product for my canvas windows. It should last 5x longer than non coated polycarbonate. I would get longer life out of acrylic except acrylic is not flexible enough to do the job.

As I mentioned earlier there is no one product fits all.
 
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You have spent more time reading this thread than it would take to make the pieces yourself. Pick one. Grab a saw and a drill. In a few years try the other one. They can both be cut, drilled and tapped with simple home tools, and purchased at Home Depot. Use plastic hardware ( nuts, bolts and washers ) and you can smooth the edges with super glue to give it a professional look. Do not let perfect get in the way of good.
 
I have both.
My original venturi faded from "bronze" to a purplish before I bought the boat at 14 years old. Then I dropped the bimini onto it and it shattered. I replaced it with plexiglass, in a "bronze" colour. In the next 30 years, the "bronze" colour has stayed bronze, but I now have a crack in one panel and crazing along the edges of the whole venturi.
I have a carport with very thin polycarbonate. In section it is 2 layers of about 1 mm separated by about 2 mm tall dividers of teh same material, making a series of square holes. It has no tint and now, after 12 years, is still clear and flexible.
I think you can use either material successfully, you just need to decide whether you want the durability of the polycarbonate over the UV resistance of the plexiglass.
 
My wind screen had also faded to a weird pink. Lots of scratches and crazing, but no breaks. I went to my local TAP plastics and looked at what they had. They stocked a light bronze transparent product that was just what I wanted. My windscreen (on a 30' trawler) would just barely fit diagonally on a 4x8 sheet, so I had to buy a whole sheet. They told me that it would be much easier for them to use my old screen as a template to cut out the new one than for me to do it at home. I dropped the old screen off and picked up the new screen (and lots of scrap) a few days later. Not only had they cut it out, but had also drilled the attachment holes and even beveled the bottom edge to match the original. Less than $400.

I had a bad feeling about the holes, but they lined up perfectly. I did it as a one-person project and it would have been much easier to have had a helper. Still, it went back on without too much problem. I'm under covered moorage (first time in the boat's life) and have now made a cover that fits the screen. It seems that most issues with shortening the life of acrylic are caused by not treating it carefully. Keep it covered when not in use. No volatile sprays. No abrasive cleaners. Don't expect more than 40 years.

I have found a couple of uses for my scraps over the years. One of them came from a print making class that I took in 2019. Turns out that acrylic sheet can be etched much like copper plate. So I did an etching of the "engineer" on one of the first boats I worked on. The acrylic sheet is scratched with a diamond-tipped scribe. Shaded areas are the result of sandpaper scratches. The plate is then inked and run through a press. Fits right in with my other nautical-based pictures.
 

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I have replaced my windscreen completely once and one part a few years later. Once after the boat shed collapsed on the boat and smashed the original screen.
The other piece I forgot what happened but I guess I broke it somehow.

THe new screen is now about 30 yr old and still shows well. I wax and buff it , by hand, each year. It is a bronze acrylic.

As far as acrylc vs polycarbonate I will take acrylic.
I used to sell and fabricate both sheet materials although, now about 30-40 years ago, as a job.

I was glad the original screen was acrylic. Polycarbonate is much stronger and able to not break under the conditions presented by the shed collapse.

I would rather deal with broken plastic sheet pieces than the damage the polycarbonate would have dealt the boat. Granted I could have repaired that damage and it's not that there was no damage from the acrylic but far less than the polycarbonate would have dealt my boat.

Just my thooughts/
 
I changed my GBC36 to polycarbonate with a light smoke color. I think the blue windscreens and so forth would look bad on my boat, others will disagree.
Work with a good fabricator, and make sure they drill all the holes exactly per the old ones.


Cost me about $250 or so, a few hours time to refit. It is very easy to scratch. Be sure to use a very clean cloth with plastic cleaner.



I heard there is a new non scratch poly now.



Jack
 
I like to think some posts are options versus just opinions as they are either verifiable as facts or certainly supported by the majority of experienced cruisers/professionals input on the subject....

....but yes there is often more than one way of doing something.....
 
Lexan is stronger but cannot be cleaned and washed with windex or anything with bleach as that will fog and scratch it.
Needs to be washed with an oil based cleaner.
We had Lexan lazertte hatches on a sailboat because they were bullet proof compared to plexiglass - could be stomped on, drop winch handle on, etc.
We would clean those with Lemon Pledge furniture polish.
Lasted many years without problem.
Never use windex on Lexan or it will fog!
 
I never used anything but water and mine still fogged...hopefully different brands and newer than 10 year old stuff fogs less or no worse than plexi..
 

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