leaking windows

[aurora]

i have 6 glass windows surrounding the helm. they have 42 year old silicon all yellowed and dry. i have 4 very minor leaks during rain...i know what the consensus will be, but i really dont want to remove and re-caulk. i was thinking of running a thin layer of clear silicon over it...is there a certain marine silicon or can i use a home depot special? thanks

[spartonboat1]

IMHO, get one of the multi-master type tools (Dremel is my choice) and strip out the old caulk down to the window and exterior frame, leaving the window in place sitting on the bed of old caulk, which is not exposed anyway.

Insert a bead of standard window glazing compound, or 3M bedding compound, against the window and bare frame, leaving about an 1/8th" of room to apply a top layer of caulk. Apply a good grade of house caulk, or maybe better yet, use 3M 4000 (non-yellowing) as the final layer. I think the 3M 4000 and 4200 comes in black, instead of white, so you could use 3M 4200 in black, since yellowing would not be a concern with black.

I had new fixed windows installed 6 years ago and the rubber molding/glazing has started to leak already, so I am in the process of doing the above to both the new and old window weather stripping.

a thought...

[SKYCHENEY]

http://www.samsmarine.com/GlassInsta...stallation.pdf

[GJH]

A superficial application of caulk will do more harm than good; follow the advice given and the handy drawings Sky posted the link to. I just did this on my front and side fixed windows a little while ago. Are you sure the water is coming from the glass area? If through the frame, that requires a whole 'nother project.

[aurora]

i'm not going to think about the frames....i'll strip out the old seals and recaulk....see what happens. but i'm not clear on the proceedure. am i stripping out just enuf of the old to have a substantial amout of a channel for the new? or do i need to take all of the old out....without un-seating the glass?

[REBrueckner]

I've seen nice charts of caulk in marine stores and their recommend application and I would urge you to read the label of anything you decide to use to be sure it's recommend for GLASS.

I have always used LIFECAULK (polysufide?) the same stuff used for the seams of teak decks, but white, but several years ago when I redid some window frame seams it cracked within a year or two...I posted about it....whether that was a bad batch or a change in formulation I don't know.

If your original caulk was silicone, then you are stuck with that...nothing else I know of will adhere. But if it's original I very much doubt it was really silicone. I avoid silicone on my boats like the plague; it doesn't have strong adhesion, can't be painted and other caulks will not adhere.

In general the more old caulk you can remove the better especially if there is dirt within any loose areas....if the old caulk is securely in place, I would not be so concerned BUT you have to correc t the leak cavity. And it is always a good idea to clean any surfaces before applying new caulk....I usually use a small brush with acetone....nothing will stick to dirt nor any oily surface residue.

[SKYCHENEY]

To seal the glass right you have to remove it. The only caulk should be under the glass, not on top of it. You should see no caulk when you are done, just the nice rubber seal on the outside.

[GJH]

That's not worded right Sky. There is caulk on the outside of the window, which is then covered by the vinyl trim. See your PDF. We used a commercial glazier's urethane sealant on the glass windows and a commercial contractor's silicon on the poly carbonate curved pilot house windows, the only thing that will really stick to those.

And I'll reiterate the point that the glass and frame must be 100% cleaned before applying sealant and trim. It took close to half a day to do one window correctly (we hope..)

[SKYCHENEY]

That's not worded right Sky. There is caulk on the outside of the window, which is then covered by the vinyl trim. See your PDF. We used a commercial glazier's urethane sealant on the glass windows and a commercial contractor's silicon on the poly carbonate curved pilot house windows, the only thing that will really stick to those.

And I'll reiterate the point that the glass and frame must be 100% cleaned before applying sealant and trim. It took close to half a day to do one window correctly (we hope..)

The glass sits on the butyl and the caulk is used to fill the gap around the edge of the glass. Hardly any of it should end up on the outside face of the glass and what does get on there gets covered up with the rubber trim.

What you see many times is that someone will try to fix a leak by squeezing silicone underneath the edge of the rubber which just makes a mess and rarely fixes the leak (for long).

I see what you are referring to, George, but the one window on my boat that I have worked on had very little caulk under the edge of the rubber.

[aurora]

my windows do not have a rubber trim...its just caulk.