Double glazed windows

[kingsebi]

I bought a Trident Voyager 35 two years ago. One reason for choosing a decksaloon yacht was the big windows. It turned out that in the two summers and one winter I lived on the boat I had the windows covered from the outside almost all of the time. Due to heat in summer, due to condensation in winter. Also some of the windows are leaking (not a big surprise on a 40 year old boat). Thus I am now considering tinted double glazed windows. I got a quote from Seaglaze in the UK for the whole set of windows (10mm security glass, frames included), but it amounts to 8000 Euros. While I'm sure they will do a good job, this is a lot of money to me. Now I'm thinking of alternatives. I suspect that the frames I have could accept double glazing. I attach a picture. What I mean is that a second window pane could go into the groove where the rubber gasket is now. The groove is about 9mm wide. Could I get a glazier to make double glazed units that would fit into my frames? My other idea is to use polycarbonate sheets and put desiccant in between, but I read on this forum that it scratches easily and flexes a lot and thus would be prone for leaking. Having changed the windows on my last boat I know that this is a big job and I want to do it right the first time. Any ideas/advice?

 

[Habebty]

Why bother unless you "double glaze" the whole hull? Get some blackout curtains or perhaps some thin Venetian blinds. The heat and cold will be coming from the hull/deck as well so you would need to insulate every surface exposed to the external heat (to slow radiant transfer), and the cold (to move the condensation layer temperature gradient outwards). How about some mirror film?

 

[NormanS]

I too have a similar size of deck saloon yacht. When I bought her, the front windows were double glazed, but the sealed units had failed and were steamed up. I took the frames to a local glazier, who fitted new double glazed units to them, surprisingly cheaply. There is still some condensation on the alloy frames, but none on the glass.
The side windows were only single glazed, and streamed with condensation. The alloy frames were such that they could not take double glazed units. Eventually I bit the bullet, and got Seaglaze to supply all six side windows, double glazed. Yes, it was expensive, but what a difference! If it is possible, do some research into the possibility of frames with a break in them to prevent condensation

 

[kingsebi]

Why bother unless you "double glaze" the whole hull? Get some blackout curtains or perhaps some thin Venetian blinds. The heat and cold will be coming from the hull/deck as well so you would need to insulate every surface exposed to the external heat (to slow radiant transfer), and the cold (to move the condensation layer temperature gradient outwards). How about some mirror film?

I plan to insulate the whole hull when I change the windows. As the windows are leaking I have to change them anyways and I will take the opportunity to insulate the hull and redo the interior lining. I have curtains, but in summer they are not enough to keep the heat out. Thus I have to cover the windows from the outside. In winter the curtains obviously don't help against condensation. On the side windows I have some sort of uv protection film, but it impairs visibility and also doesn't keep enough heat out in summer. I have costum made covers on the outside that work well, but I'd like to be able to look out of my decksaloon more time of the year. I might add that I'm sailing in the Mediterranean.

I too have a similar size of deck saloon yacht. When I bought her, the front windows were double glazed, but the sealed units had failed and were steamed up. I took the frames to a local glazier, who fitted new double glazed units to them, surprisingly cheaply. There is still some condensation on the alloy frames, but none on the glass.
The side windows were only single glazed, and streamed with condensation. The alloy frames were such that they could not take double glazed units. Eventually I bit the bullet, and got Seaglaze to supply all six side windows, double glazed. Yes, it was expensive, but what a difference! If it is possible, do some research into the possibility of frames with a break in them to prevent condensation

Thanks for sharing your experience. I thought it would make a big difference from single to double glazing! All houses have double glazing nowadays. Do you think my frames would take double glazing? It seems like taking them to a glazier would be a much cheaper option, even though I understand there still would be condensation on the frames. Do your double glazed windows keep out the heat in summer?

 

[The Q]

I had a caravan with double glazed glass windows they are incredibly heavy.. not something you'd want high up in a boat..

If you want double glazing then use thin perspex or similar put on the inside, just a couple of tiny gaps at the bottom to let the condensation leak out.
This is something I've done to my model railway shed, it does make a huge difference in keeping the heat in, without the cost of true double glazing units...

 

[NormanS]

I plan to insulate the whole hull when I change the windows. As the windows are leaking I have to change them anyways and I will take the opportunity to insulate the hull and redo the interior lining. I have curtains, but in summer they are not enough to keep the heat out. Thus I have to cover the windows from the outside. In winter the curtains obviously don't help against condensation. On the side windows I have some sort of uv protection film, but it impairs visibility and also doesn't keep enough heat out in summer. I have costum made covers on the outside that work well, but I'd like to be able to look out of my decksaloon more time of the year. I might add that I'm sailing in the Mediterranean.



Thanks for sharing your experience. I thought it would make a big difference from single to double glazing! All houses have double glazing nowadays. Do you think my frames would take double glazing? It seems like taking them to a glazier would be a much cheaper option, even though I understand there still would be condensation on the frames. Do your double glazed windows keep out the heat in summer?

I don't know if your existing frames could take double glazed units. You say the groove is about 9mm, but I'm not sure if you mean 9mm in total, or if that is what's left by the existing glass.
My main reasons for going for double glazing on my side windows, were to reduce condensation in cold weather, and to thereby improve visibility. I sail on the West Coast of Scotland, and so keeping out the heat is not a major priority. ? It's a well known fact that double glazing is effective as a barrier against both cold and heat.

 

[Stemar]

You won't get rid of condensation by fitting double glazing panels into an aluminium frame. The ally will act as a cold leak and will be dripping in no time. Could you fit domestic secondary double glazing? The stuff with a plastic frame should make it possible to follow curved corners.

That would improve matters, but won't stop condensation on it's own, just move it from the windows to the backs of lockers and other places you don't want it. Most of the liveaboards I knew ran a dehumidifier throughout the winter, but you'd still want to insulate the hull in the backs of lockers. On milder days, the dehumidifier may well be all the heat you needs, so running costs needn't be excessive

 

[Iliade]

What about thin plastic (perspex, lexan, w.h.y.) sized to completely cover the windows and frames, stuck to the hull with a foam tape? (With dribble gaps at the bottom.)

Plus what Stemar said ^ You have to get rid of the damp air somehow; I ventilated the boat when I lived aboard as dehumidifiers were less commonplace then.

 

[V1701]

What I would suggest is fix the leaking windows, have a look on Youtube for hints, other people have very likely done the same thing before - it might involve removing and rebedding the frames, e.g. Get some white blinds for summer use, IKEA sell some very cheap ones that work well, I have them in my wheelhouse to reduce the glare and keep things comfortable in hot weather and they make a real difference despite not being blackout blinds. For the winter you'll need a good quality dessicant type dehumidifier, it'll make a huge difference to comfort aboard, really does make the difference between having a dry boat and a sopping wet one. There will likely be people who tell you that dehumidifiers are a waste of time unless you hermetically seal your boat and that you will be trying to dehumidify the planet earth itself. This is absolutely not true - of course you close hatches, vents, etc. when using your dehumidifier...

If you do the above your boat will be comfortable and habitable and if you haven't done already get yourself an electric blanket...

 

[kingsebi]

I had a caravan with double glazed glass windows they are incredibly heavy.. not something you'd want high up in a boat..

If you want double glazing then use thin perspex or similar put on the inside, just a couple of tiny gaps at the bottom to let the condensation leak out.
This is something I've done to my model railway shed, it does make a huge difference in keeping the heat in, without the cost of true double glazing units...

Thanks for the very practical advice, I will consider doing it like that.

I don't know if your existing frames could take double glazed units. You say the groove is about 9mm, but I'm not sure if you mean 9mm in total, or if that is what's left by the existing glass.
My main reasons for going for double glazing on my side windows, were to reduce condensation in cold weather, and to thereby improve visibility. I sail on the West Coast of Scotland, and so keeping out the heat is not a major priority. ? It's a well known fact that double glazing is effective as a barrier against both cold and heat.

9mm is left by the existing glass, but then its two grooves, one for the existing glass (which I suppose is about 9mm aswell) and the one left free - that's why I'm confused. If it was one groove I would be sure that it could accept double glazing.

I see. If it works for you on the West Coast of Scotland it should do the job in the mild winters of the Mediterranean!

You won't get rid of condensation by fitting double glazing panels into an aluminium frame. The ally will act as a cold leak and will be dripping in no time. Could you fit domestic secondary double glazing? The stuff with a plastic frame should make it possible to follow curved corners.

That would improve matters, but won't stop condensation on it's own, just move it from the windows to the backs of lockers and other places you don't want it. Most of the liveaboards I knew ran a dehumidifier throughout the winter, but you'd still want to insulate the hull in the backs of lockers. On milder days, the dehumidifier may well be all the heat you needs, so running costs needn't be excessive

I understand the argument about aluminum frames and will look into domestic double glazing.

What about thin plastic (perspex, lexan, w.h.y.) sized to completely cover the windows and frames, stuck to the hull with a foam tape? (With dribble gaps at the bottom.)

Plus what Stemar said ^ You have to get rid of the damp air somehow; I ventilated the boat when I lived aboard as dehumidifiers were less commonplace then.

I thought about acrylic/polycarbonate on the outside to double as stormboards aswell.

What I would suggest is fix the leaking windows, have a look on Youtube for hints, other people have very likely done the same thing before - it might involve removing and rebedding the frames, e.g. Get some white blinds for summer use, IKEA sell some very cheap ones that work well, I have them in my wheelhouse to reduce the glare and keep things comfortable in hot weather and they make a real difference despite not being blackout blinds. For the winter you'll need a good quality dessicant type dehumidifier, it'll make a huge difference to comfort aboard, really does make the difference between having a dry boat and a sopping wet one. There will likely be people who tell you that dehumidifiers are a waste of time unless you hermetically seal your boat and that you will be trying to dehumidify the planet earth itself. This is absolutely not true - of course you close hatches, vents, etc. when using your dehumidifier...

If you do the above your boat will be comfortable and habitable and if you haven't done already get yourself an electric blanket...

I have a woodburner for the winter, so humidity per se is not the problem.

 

[NormanS]

Re the two grooves in the alloy frames: That what my side frames were, and you are correct, they cannot take DG units. I think the origin of that type of frame was that it could be used for sliding opening windows. I winter ashore, but still make some use of the boat. I have polycarbonate storm windows, which I put on in the winter, and which stop any condensation from forming on the frames.

 

[kingsebi]

Too bad about the frames, but that's what I thought. Interesting about the stormboards. I will think about the whole thing. As I plan to live on the boat for a long time I want to find the best solution.

 

[pandos]

You can probably get a reflective layer that will keep the heat out in summer.

If it was my boat I would work out the thickness of the existing glass and ask local double glaziers what they could do.

It might be that squaring off the openings, doing away with the frames and fitting stepped units with the outer pane frittered and bonded to the hull might be an option.

I doubt the additional weight of a few panes of glass would make any great difference in such a heavily built boat.

 

[kingsebi]

You can probably get a reflective layer that will keep the heat out in summer.

If it was my boat I would work out the thickness of the existing glass and ask local double glaziers what they could do.

It might be that squaring off the openings, doing away with the frames and fitting stepped units with the outer pane frittered and bonded to the hull might be an option.

I doubt the additional weight of a few panes of glass would make any great difference in such a heavily built boat.

I will do that when I get back to the boat in spring. Stepped units are another option, thanks for the input. I don't think the additional weight would be of concern either.

 

[Findhorn]

I bought a Trident Voyager 35 two years ago. One reason for choosing a decksaloon yacht was the big windows. It turned out that in the two summers and one winter I lived on the boat I had the windows covered from the outside almost all of the time. Due to heat in summer, due to condensation in winter. Also some of the windows are leaking (not a big surprise on a 40 year old boat). Thus I am now considering tinted double glazed windows. I got a quote from Seaglaze in the UK for the whole set of windows (10mm security glass, frames included), but it amounts to 8000 Euros. While I'm sure they will do a good job, this is a lot of money to me. Now I'm thinking of alternatives. I suspect that the frames I have could accept double glazing. I attach a picture. What I mean is that a second window pane could go into the groove where the rubber gasket is now. The groove is about 9mm wide. Could I get a glazier to make double glazed units that would fit into my frames? My other idea is to use polycarbonate sheets and put desiccant in between, but I read on this forum that it scratches easily and flexes a lot and thus would be prone for leaking. Having changed the windows on my last boat I know that this is a big job and I want to do it right the first time. Any ideas/advice?

View attachment 130132

I also have Voyager 35 and had the same issues particularly condensation.My solution was to fit polycarbonate secondary glazing with holes fitted with bungs,top and bottom to enable purging of the gap using co2/argon gas mix .I used 6mm foam tape as a seal between frame and polycarbonate and after much faffing about and experimenting I now have most of the windows free of condensation with the exception of the aft port a and starboard ones.
The next step is to insulate the remainder of the exposed frames with suitable foam tape and hopefully have a drip free interior .
A few tips:-
Make sure the external window/frame seals are totally water tight
Acrylic is probably better than polycarbonate in this application (poly is a bit too flexible to get a good seal between the fasteners)
When doing the final fit get the humidity in the boat right as far as you can ( dry day and de-humidifier running flat out)
If you use pop studs every four or five fasteners you can use them to fasten internal covers/curtains

 

[Findhorn]

I also have Voyager 35 and had the same issues particularly condensation.My solution was to fit polycarbonate secondary glazing with holes fitted with bungs,top and bottom to enable purging of the gap using co2/argon gas mix .I used 6mm foam tape as a seal between frame and polycarbonate and after much faffing about and experimenting I now have most of the windows free of condensation with the exception of the aft port a and starboard ones.
The next step is to insulate the remainder of the exposed frames with suitable foam tape and hopefully have a drip free interior .
A few tips:-
Make sure the external window/frame seals are totally water tight
Acrylic is probably better than polycarbonate in this application (poly is a bit too flexible to get a good seal between the fasteners)
When doing the final fit get the humidity in the boat right as far as you can ( dry day and de-humidifier running flat out)
If you use pop studs every four or five fasteners you can use them to fasten internal covers/curtains

 

[kingsebi]

I also have Voyager 35 and had the same issues particularly condensation.My solution was to fit polycarbonate secondary glazing with holes fitted with bungs,top and bottom to enable purging of the gap using co2/argon gas mix .I used 6mm foam tape as a seal between frame and polycarbonate and after much faffing about and experimenting I now have most of the windows free of condensation with the exception of the aft port a and starboard ones.
The next step is to insulate the remainder of the exposed frames with suitable foam tape and hopefully have a drip free interior .
A few tips:-
Make sure the external window/frame seals are totally water tight
Acrylic is probably better than polycarbonate in this application (poly is a bit too flexible to get a good seal between the fasteners)
When doing the final fit get the humidity in the boat right as far as you can ( dry day and de-humidifier running flat out)
If you use pop studs every four or five fasteners you can use them to fasten internal covers/curtains

Thank you, very interesting. This is a solution I shall contemplate aswell. Your internal covers look nice. Apropos Voyager 35, great boat isn't it?