Polycarbonate or Perspex

[KAM]

Just reasealing my windows. These are currently perspex but I was considering changing to polycarbonate. I have used a lot of polycarbonate in industrial applications and aircraft canopies and would never dream of using perspex with all it's brittleness and crazing problems I have heard that polycarbonate is unsuitable for marine applications ( One supplier told me the RNLI don't use it because it goes cloudy) but I see there are now UV resistant types available. Does anyone have any experience of using polycarbonate for boat windows.

 

[bluedragon]

The problem with polycarbonate being used in the auto industry for lights, etc, was I believe scratch resistance, and that's mentioned here as well http://www.eagleboatwindows.co.uk/perspex.asp but you might have a word with these guys who supply a coated version.

 

[boatbuilder]

Find a supplier of "Makrolon Hard" RNLI used to use it but I am not sure if they still do.

 

[Tranona]

Polycarbonate every time for strength and durability - and very little extra cost.

 

[CharlesSwallow]

Find a supplier of "Makrolon Hard" RNLI used to use it but I am not sure if they still do.

He's called "Eagle Boat Windows"

Made a set of new makralon windows for me around 18 years ago. The current owners of that boat still have them and they are as good as new and polish up a treat.

Chas

 

[wilkinsonsails]

All polycarbonates deteriorate with UV,so you need to cover them.
Makrolon is used where you might want a windscreen wiper.
Our original windows Perspex I think, were replaced 10 yrs ago.
We have found that the sealant type is fairly critical we tried Sikaflex but thats now letting go.The smoked Lexan we used then, is just starting to craze.That s ten yrs in the UK.
Cindy

 

[TonyMS]

Tinted polycarb windows I put in 20 years ago are still fine, apart from some scratches.

On another boat we tried to clean up with acetone - bit of a disaster as it destroyed the surface.

But for strength and ease of working, polycarb wins every time.

Tony

 

[TradewindSailor]

I've used smoked UV resistant polycarb for the main windows in the deck saloon on one boat. Within three years in the tropics the surface had gone cloudy with minute crazing on the outer surface. As is was already bad I polished it with Macleans toothpaste ..... which worked well. I have also tried a medium grit plastics polish which was easier to use and did the same job. The problem is that it has to be polished every month or so now.

Polycarb is more susceptable to damage from solvents than acrylic, and much more expensive ..... although if you have to pay for labour the % difference won't be great.

I'm goiing to use acrylic to replace the 20 hatches and windows on the Catana. This is because virtually any cleaner used on the decks or in the cabins is likely to damage Polycarbonate ..... and also Acrylic is easier to obtain down here in Mexico.

 

[2TALLTARY]

polycarbonate

polycarbonate is a great product. 25 times stronger than acrylic it is great for windows. it does scratch but overall is a great option. use it all the time. i also found a great website. tells ya more and has some polycarbonate for sale.
http://www.iplasticsupply.com/materials/polycarbonate-lexan-tuffak-makrolon-cyrolon-sheet-rod

 

[Gordonmc]

I replaced the perspex windows on my boat with polycarbonate ten years ago and there is, so far, no UV damage at all.
The windows screwed directly onto the mahogany saloon coaming on a bed of clear marine silicone which had no effect on the polycarbonate. Cut with a slow running jigsaw with a plastics blade, then wet 'n dry the cut edges. Screw holes were drilled slightly oversized to allow for some movement.
Poly does scratch easily, but unless you attack with a scourer it shouldn't be a problem. A plus is that the heads window can be frosted with 120 grit abrasive.
I got the polycarbonate (offcuts) from a glazier - £15 for six windows