Polycarbonate or Perspex

[bendyone]

Should I use polycarbonate or perspex 8mm sheet to replace the windows on my Hunter 26? The windows are screwed on to the sides of the cabin with some sort of sealer. Which will last longest? Poycardonate I understand will be stronger but is this an advantage?

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[boatmike]

Polycarbonate is soft and scratches easily. You can get it with a surface hardening treatment to stop it scratching but it's quite expensive. Perspex is far cheaper and more than adequate for your needs.

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[wizard]

The Hunters normally have a thin black foam material which is sticky on the side nearest to the GRP. Its put on in one sheet per side cut out to match the windows and then the perspex is then screwed through to the GRP.

Your original windows should come off and leave the black seal behind. Use the old window as a pattern for the new ones and get the screw holes aligned and countersunk at the same time.

When screwing back the new windows use just enough pressure to compress the thin black foam or else the perspex may split.

Good luck

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[FullCircle]

Would recommend the use of Makrolon by Bayer, which is what is used for Riot Shields, and is tough as old boots. It is also UV resistant. Perspex has a tendency to shatter, and microcracking or crazing propagates with in 5-6 years if you use the cheap variety. It also does not have the resistance to impact that I believe is a very important attribute.

<hr width=100% size=1>Really looking forward to the cheapo nasty Jeanneau 35 in March.

 

[TonyMS]

I used PC on my Hunter Delta about 10 yrs ago, and it's still fine. In my experience scratching is no worse than with Perspex.

Prefered it over Perspex partly because it's easier to machine, with no danger of its cracking, and partly for strength, as I was enlarging the window openings.

Tony

<hr width=100% size=1>www.montgomery-smith.org

 

[Avocet]

Polycarb can go "milky" after a period of time but, as has been said, it's virtually unbreakable - perspex isn't.

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[lumphammer]

I used bronze coloured polycarbonate on my Achilles 840, which is fixed the same as yours. A tip some one on this forum gave me was to spray the inside face where the sealant is to go with a matching colour, this hides all the sealant and looks much better.

leave the backing paper in place, position against the window and mark round the window from the inside. Lightly score the backing paper and peel away the bits that are round the outside. I sprayed mine with standard black paint. Use plenty of silicon sealant, ( the odourless/neutral) sort that doesn't smell of acetic acid, screw up tight enough to extrude the silicon, leave to cure, then tighten up the fixing screws. remove backing paper when all fixed (I found I had to dampen the backing paper because the spray paint came of the paper and stuck like glue to the window, dampening made this less)

Richard

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[Dave_Snelson]

Definately polycarb. Its many times stronger than perspex and much more UV resistant. I have used it for my companion way hatch and chart table top - perfect.

<hr width=100% size=1>Madoc Yacht Club
<A target="_blank" HREF=http://www.madocyachtclub.co.uk>http://www.madocyachtclub.co.uk</A>

 

[roger]

I used Makrolon for two windows at home (because of vandals) They lasted for at least ten years and I replaced them because they went yellow - and the vandals had given up. Yes its very strong. It does yellow sllowly but did not for me craze. Polycarbonates respond oddly to some solvents. We found that tapping compounds used on blocks ov poly carbonate tended to induce cracks.It would e worth checking carefully which sealants are most suitable.

<hr width=100% size=1>Roger