Glass window bonding question

[svrevelations]

One of our glass (laminated glass) side windows sprung a leak. The window is bonded into a recessed epoxy frame. It seems like we will have to remove the window, clean everything and then bond it back in place. The original bonding was done with SikaFlex - not sure which one though. My questions are;

1. What is the best way to cut the existing bond/seal to get the window out.

2. What is the best bonding material to rebed the glass window?

[JPA Cate]

Is it situated so you can get a coping saw onto it? Or, a wire with cotter rings at the ends for sawing with? Otherwise, a chisel, used VERY carefully. Knife blade (very sharp)? It's always a hassle, and finicky, to boot.

Good luck with it.

Ann

[sparrowhawk1]

To remove use two very thin putty knives. And maybe a razor knife. first break the seal all the way around. gently tap the putty knives in with a hammer and then just start slowly putting pressure and continue severing the seal. Once it starts separating you can use a chisel or a big screwdriver but be careful wider is better.

Butyl rubber. It comes in white black or grey

[HappyMdRSailor]

Revelations,

Look at this thread here... (I started you on page 2)

http://www.cruisersforum.com/forums/...-121338-2.html

Our friend Siujin is removing portlights and having a tough go of it because of the install materials.... while not the same thing... many of the methods are the same.... Pay particular attention to the suggestions given by minaret.... He is an insanely knowledgeable professional who limelights as a comedian too...

Sharp blade knives... Heated sharpened putty knives... Wire... Wood wedges would be my tools.... Not sure for sika about the anti-bond he suggested works wonders... I have zero experience using it...

Good luck!

[svrevelations]

Thank you all for the advise, links and suggestions.
Much appreciated!

[Andrew Troup]

Be careful, because over time, with this design of frameless port, UV tends to degrade the bond.

This appears to be true even for adhesives which are highly rated in respect of this particular challenge, and here in NZ where UV levels are rather high, even the best installations often start letting go after around a decade.

[Terra Nova]

Andrew--good point. Most of the newer boats with bonded windows use a special coating over the bonding area to keep UV from attacking the sealant, through the glass.

Sikaflex 296 is what is usually recommended. It only comes in the "sausage" packs, so requires a special caulking gun. But it is a joy to apply and comes out like mayonnaise.
Sikaflex - 296 -- 20 oz. Unipac - Marine Window Adhesive

[Andrew Troup]

The interesting question is, how well does that coating "keep" the UV from attacking the sealant, as opposed to mitigating the rate of deterioration.

I know of one case where the window started to pop within ten years, despite the UV-protective coating having been applied correctly, and remaining intact.

The case I like to keep in mind is the situation where the boat is temporarily keel up, and something like a battery breaks loose and tumbles across or into a port which has no mechanical retention.

I would certainly have strong storm shutters ready, on any boat with such a detail travelling offshore, and they would be of a type which kept the water out in the absence of the port, rather than simply being intended to bear the brunt of external impact, as some shutters do.

[coxjam]

Dow Corning 795 is what hunter and Catalina recommend. An oscillating saw with a putty knife tip really makes this easy. Another method, use a guitar string once you've broached the caulk through. Then just pull the wire along and it cuts thru the caulk easy but requires 2 people.