New Windows

[snoopebj]

I hope this might help someone contemplating new windows on the Investigator.
After researching various boat websites and finding a knowledgeable, helpful and sympathetic local supplier Joe's DIY Unanderra I pulled out my old crazed scratched and worn perspex windows (they broke apart as I pulled them out!) The 6mm uv tinted polycarbonate replacements were cut and bevelled using the old ones as patterns. Joe advised me not to use screws. rubber sealants or adhesives as technology has moved on. He supplied me with 3M VHB double sided tape (used by local boat builders Seawind Yachts ). I was still skeptical until he gave me a demo - instant adhesion and sets within 24hrs. Also used on aircraft.
I first had to clean the window edges thoroughly then the open side of the tape roll is pressed on along the edge all the way around the window perimeter. I made the join at the bottom in the middle. Leaving the protective outside tape on I peeled off the protective plastic from the poly window and placed it over the taped window and carefully marked in pencil around the edge ready for the installation. There is only one chance at getting the window on straight as it bonds immediately!!)
The outer plastic covering is then stripped off the tape and the window carefully put in place. You then push the window in firmly all the way around. After leaving to set for 24hrs I then masked around the windows and filled in the gap between the tape and the window edge with Sikaflex 291 marine sealer adhesive (black) and trimmed off the excess. This is more for neatness and looks as the tape bonds the window in.
While I was doing the job I decided to install a hatch window as well also putting in two internal pad bolts to strengthen the hatch. (see 'Offshore modifications Current Affair front hatch bolts'.)
Sounds like a lot of work but easier than screwing and glueing and the end result a lot tidier.
Items and cost
Makrolon 6mm tinted polycarbonate imported by Laserlite Australia (cut and bevelled) $250
3M VHB double sided tape $5.50 metre X 9m = 49.50
Sikaflex 291 marine sealer adhesive (black) = 18.00
Total $317.50

[Mark]

Fantastic!

Where did you get the perspex from and who cut it to size etc?

This is a mod worth considering. Many thanks for post.

Cheers

Mark

[snoopebj]

Hi Mark
Not affiliated. He's very helpful and worth the money. rare these days.
best of luck

[Mark]

Just thought I would let you know that after all this time i have finally followed up on this with an email to Joe's to ask if he has the original profile you gave hime to cut and supply me with new windows. Lets see what resolves as its certainly time for me to get this done.

Best

Mark

[snoopebj]

Hi Mark
Good Luck - it has worked for me since then with no leaks.
See p.m.
cheers

[Mark]

All

I have now, after several weeks preparation, completed the replacement of Aminee's windows according the the procedure outlined by Emrys in this thread. I even used his DIY guy to supply and cut the polycarbonate for me and ship to Batemans bay. I obtained the 3M-VHB tape from 3M directly - cost $120 plus postage as I could only buy a 33M roll!

The process was relatively easy - my wife and I started it at noon this Sunday and 4 hrs later all windows were in place but the silkaflexing was left until 24hrs later. The windows really do bond extremely tightly and one needs to to get them prepositioned before committing to placement. Another pair of hands (and eyes) makes this relatively easy.

For me the worst part was sealing off the gap with the Sika a messy job, very slow and i did not always get the silkaflex filling the gap completely, but my reasoning is as long a a good seal in evident it should last a good deal of time. One can actually see how far it has penetrated in relation to the bonding tape.

I also found it important to mask the edges and then remove the tape before the silka has begun to set. The outcome was ok a - few messy spots around the window edges but I will try and trim up with a blade in a day or so.

I would highly recommend this method for window replacement. I plan now to test for waterproofing in the next couple of days.

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By the way if anyone wants old (and in good condition) old aluminium frames then I am happy to give them away for free provided the recipient pays for postage.


Cheers

Mark

Update: 1.11.14 the windows are 100% watertight to date this after much testing plus regular washes and quite a number of sails with water flying over windows.