If you can get it out without breaking it too badly, remove it and take it to Plastix in Brookvale or Banksia. They'll cut you a new one out of Polycarbonate or Acrylic in either clear or a tint. It's not that expensive. Hardest job is sealing it against the weather when you put in back in.

If you can't get it out and have it out for a few days, get a big bit of paper and carefully trace a template and they can work from that. You'll need to know how thick you want the acrylic though. Mine is 10mm. But you can get it in a variety of thicknesses.

I'm about to replace my fixed ports...I'm going for tinted polycarbonate.

cazou34 said..

MichaelR said..
If you can get it out without breaking it too badly, remove it and take it to Plastix in Brookvale or Banksia. They'll cut you a new one out of Polycarbonate or Acrylic in either clear or a tint. It's not that expensive. Hardest job is sealing it against the weather when you put in back in.

If you can't get it out and have it out for a few days, get a big bit of paper and carefully trace a template and they can work from that. You'll need to know how thick you want the acrylic though. Mine is 10mm. But you can get it in a variety of thicknesses.

Thks MichaelR, will do that. What material did you choose?

I haven't chosen it yet. I was recommended a mid tone grey acrylic. The thicker the better for security, and in case you get hit hard by a wave. One of the lads on tophatyachts.com did it with his Mark III Top Hat and used acrylic. Greg said getting the acrylic cut was easy. The re-fitting was the tricky part, there are so many methods from Windscreen adhesive to drilling and screwing and sealing with sika or silicone. I like the idea of windscreen sealant, but it's very messy.
I use acrylic most days in my sign printing trade. It's got a lot of uses from laser routed lettering to light box panels and plenty of other uses. Cutting a window panel for you should be a doddle for them.

the coastal passage online magazine, in their technical section has a good guide to fit new portholes.
i followed their guide 6 or 7 years ago and have had no leaks or problems since

I would certainly, and have done it. Mine were on the outside, so more evident of any snafu's. Took window out and used it as the template, it was actually quite fun!
I needed a normal saw for the long straight cuts, and jigsaw for rounded edges. I tried the jigsaw on the long cuts, but it didn't work as well as the saw. I must admit I bought more so I had enough scrap to test my cutting skills first.

Polycarbonate is tough, but scratches easy and within a few years yellows significantly. Cast (as opposed to extruded) acrylic is the best bet, IMHO, in all but the most extreme applications.

If you want to cut out from your own sheets, and have a router, you can use a pattern router bit to copy the old shape to the new material.