Glass siliconed into frame? good or bad?

[snowbird30ds]

I've posted this on PBO forum but not many replies so maybe not saily enough so posted here too.
I've been given a price to refurb the screens on my princess 30ds but mentions silicon between glass and frame, acceptable or bodgy? Opinions sought.
They are pointy cornered rhomboid shape if that makes any difference.

 

[tillergirl]

I was looking at a boat windows web site and watched the videos that shew that silicon was used but mentioned that butyl could be used. Personally I think butyl is the better product for that application - much more reliable contact between glass and ally BUT is so very easy to make a mess. Butyl tape can be obtained. I used silicon years ago on wood and metal frame - hopeless. The silicon didn't like the wood - poor bonding, different expansion temperatures. Last winter on a different boat I had to strip out the silicon twix fiberglass/glass/ally frame. It could be that when it was used insufficient care was taken with cleanliness of course but the silicon had failed. So far the butyl hasn't.

 

[MrB]

Can you take some pics of the screens. Is there a gasket between the frame and the glass? (probably black/white rubber inside and out ) Silicon will seal a window but I would have thought they would be contained by gasket than bonded on an older boat.

 

[gordmac]

Tiger seal used to be the stuff for sticking windscreens in.

 

[Seastoke]

Tiger seal used to be the stuff for sticking windscreens in.

Steady Tiger.

 

[MapisM]

I've been given a price to refurb the screens on my princess 30ds but mentions silicon between glass and frame, acceptable or bodgy?

Bodgy, but also acceptable - sort of.
I mean, normally there is a gasket inside framed glasses, and that should be enough to grant a perfect seal.
Otoh, over time gaskets can lose elasticity and/or integrity, and it might be difficult to find a like for like replacement.
So, if whoever quoted you the job knows that some sealant is necessary to assure a good result, well, that's better than refurbishing the screens and still have leaks, I reckon.

Btw, beware of wording: the yard could have written "silicon" just because they know it's something everyone understands, but there are literally hundreds of sealants, based on different chemistry and much stronger than the old acetic silicone.
I would ask them what stuff exactly they are thinking to use.

 

[MrB]

Bodgy, but also acceptable - sort of.
I mean, normally there is a gasket inside framed glasses, and that should be enough to grant a perfect seal.(It's known as captive gasket and all sorts and shapes can be found on ebay) ((the other is wedge gasket and can also be found on ebay))
Otoh, over time gaskets can lose elasticity and/or integrity, and it might be difficult to find a like for like replacement.(Washing-up liquid and degreaser type detergents kills the gasket removing it's silicon....tell your window cleaner that too)
So, if whoever quoted you the job knows that some sealant is necessary to assure a good result, well, that's better than refurbishing the screens and still have leaks, I reckon.

Btw, beware of wording: the yard could have written "silicon" just because they know it's something everyone understands, but there are literally hundreds of sealants, based on different chemistry and much stronger than the old acetic silicone.(Neutral cure is better than acetic, just takes longer to set/cure)
I would ask them what stuff exactly they are thinking to use.

I fully agree with MM, just added some bits in bold to help.

 

[Trundlebug]

You can buy glazing silicone from the likes of Screwfix and Toolstation, so it's an accepted use for it.
I think it can be used for fish tanks and the like.

I bought some to fix and seal my shed windows in place, it was MUCH easier than using traditional linseed oil putty.

So far, about 18 months on and all is well, with good adhesion to both glass and surrounding wood frames, and finish is OK too.
But it's not the same as a marine environment of course.

Hope that's useful for info anyway

 

[Ferris]

Did this on a broom years ago. Disassembled the window frames and rebuilt with sikaflex 291 I think. B**tard of a job as we had to refit the windows into the opes while the sika was still wet so that they would fit. Never leaked again however.

I’ve read on here that some people use non setting builders mastic for this which might be easier to use. We tried using dry window seals and they leaked like a sieve.

If I had to do it again I’d be letting somebody else do it.