The Windows sealant dilemma on SV Oddity.

[GregOddity]

So yesterday, we started looking at the windows and realised one very simple fact, besides the aluminium and glass being in good condition, we knew nothing of windows and the best way to seal them. We hear people say “do not use Sicaflex to bond it” “use Normal silicone “etc.
That led me to start looking into the subject at hand. Now from a material properties point of view, I can see a few elements that can be considered complicated. Temperature absorption varies on the different materials leading to fast expansion and contractions that can vary greatly and having resonance shock waves travel through the hull when beating, along with vibrations and having the aluminium frame acting as a heat sink for the glass … I got completely lost.
So as an engineer I deconstructed the problem. Here’s what I got. Who else has the problem and how did they solve it.
Airplanes. Airplane fuselages and the stresses applied to it make it interesting to bond different materials and keep a water tight seal. Trust me when I say you do NOT want leaks on the instruments of the plane you happen to be flying in at 30.000 feet. So how did they solve it?
They use a bonding process on the inside and a rubber seal on the outside. Rubber is used as a pressure seal to guarantee that if the silicone bonding fails, no water is coming from the outside.
(It’s a bit more complicated but that’s what it boils down to)
What’s next? Well YOUR car. Why does your car still use a rubber seal on the outside? Same reason apparently.
Sailboats? Well this is what got me lost. Most are simply bonded and the advice I received was just to use silicone. But it puzzled me and I decided to follow the lead of @ghostlymoron and pay a visit to the contact he gave me. It’s a company called Seals + Direct in the New Forest which made for a nice drive. But here’s the thing, going somewhere to ask something, you’re not even sure of what is it you need, not knowing if you even want to buy anything, is always interesting and sometimes, people just send you on your merry way with the fastest thing they can think of, to get rid of you as soon as they sense you’re not a Big Fish client.
But to our surprise and great amusement, (thanks @ghostlymoron ) not only were they very helpful as they also took the time to explain exactly what our options should be according to them. Mr Phil Howard a director that came to our aide run us through a number of options starting with bonding with silicone. (cracks and leaks galore) then finally advising us to try a 3-component approach to guarantee the best result. It starts in our case with neoprene closed cell tape on the bottom of the channel to support the glass and prevent any water from moving to the inside, then on the inside and against the frame wall a silicone bead that will be compressed by the glass against the frame, and finally with a rubber seal applying pressure on the glass on the outside and guaranteeing the watertight seal desired. This was recommended to allow for vibration and temperature fast movements without the nasty effects of micro fissures that keep widening until a leak appears if it is only a silicone bead around the window. The final step should be using neoprene closed cell tape against the hull where the frame will be screwed tight and butyl around the outside between the hull and frame.
I’m still looking for the right primer for the glass/silicone to guarantee a perfect adhesion
Small note, the Neoprene strip on the bottom of the channel also allows for an easier cutting of the bead should the need arise.

So, first problem solved for Oddity, now just a jet wash and a polish and we’ll soon be sailing.

I’d like to thank all the people that gave us advice and led us to find a solution were happy with.
I do recommend and thank the people of Seals + Direct for the time they took for us. Greatly appreciated! http://www.sealsdirect.co.uk/shopping.asp?intDepartmentId=4#22

 

[vyv_cox]

Just for info, modern automotive screens and fixed windows are attached using polyurethane adhesives. The metal or GRP and glass are primed with an accelerated butyl and ethyl acetate compound, then the glass is bonded to the surround using material that appears very similar to Sikaflex291. Last week I fitted new fixed windscreens to my motorsailer using this technique, all supplied by the Vehicle Glass Company. http://www.thevehicleglasscompany.co.uk/

 

[GregOddity]

Just for info, modern automotive screens and fixed windows are attached using polyurethane adhesives. The metal or GRP and glass are primed with an accelerated butyl and ethyl acetate compound, then the glass is bonded to the surround using material that appears very similar to Sikaflex291. Last week I fitted new fixed windscreens to my motorsailer using this technique, all supplied by the Vehicle Glass Company. http://www.thevehicleglasscompany.co.uk/

Yes, I’ve also been looking into that, it seems that most of the advice given is based on the premise that the windows will leak and you will have to remove the all thing, clean and reseal and do it again. To me it seems that by using no matter what or being afraid of not being able to remove the window to reseal a badly sealed window, or using the wrong mats or technique, led to the view that the leaks will happen and you will need to reseal the window. My cars never leaked. I’ve got a few hours flight time to my name and also never saw a leak. There has to be a reason why so many leaks happen on the window seals on sailboats and I for one do not think it has to do with wear and tear, but with the construction or assembling technique.


One thing is for sure. I do not want to have leaks on my windows!

 

[Fr J Hackett]

Yes, I’ve also been looking into that, it seems that most of the advice given is based on the premise that the windows will leak and you will have to remove the all thing, clean and reseal and do it again. To me it seems that by using no matter what or being afraid of not being able to remove the window to reseal a badly sealed window, or using the wrong mats or technique, led to the view that the leaks will happen and you will need to reseal the window. My cars never leaked. I’ve got a few hours flight time to my name and also never saw a leak. There has to be a reason why so many leaks happen on the window seals on sailboats and I for one do not think it has to do with wear and tear, but with the construction or assembling technique.


One thing is for sure. I do not want to have leaks on my windows!

I would say that it has to do with the bonding of the substrate to two different materials Fibreglass and metal or metal and glass. It is not easy to achieve both but it can be done and obviously is in the motor and aeronautics industries but they spend a lot of time and money on research and materials the boat industry does not. Applying some of the techniques from either of those industries could go a long way towards improving the marine problem but different metals, alloys and rubbers all require different adhesion promotors.

 

[GregOddity]

I would say that it has to do with the bonding of the substrate to two different materials Fibreglass and metal or metal and glass. It is not easy to achieve both but it can be done and obviously is in the motor and aeronautics industries but they spend a lot of time and money on research and materials the boat industry does not. Applying some of the techniques from either of those industries could go a long way towards improving the marine problem but different metals, alloys and rubbers all require different adhesion promotors.

Right on the nerve, It seems that the boating industry does not follow the same procedures to cut cost by developing a common Interbrand approach like the auto and aviation industries, instead it’s a collection of add hoc approaches and solutions that ended up being transmitted to the final owner by the use of sometimes even bathroom silicone as I saw someone doing on YouTube.
The bonding of the different materials is indeed something that needs a bit of research, having said that I do believe it’s not a problem without a solution.
It’s a bit of a choice between spending a bit more time looking for the right solution or just accepting that it will leak and bond it in an easy way to take out.

 

[PaulRainbow]

You are making a meal of this. It's simple, stick them in with butyl, like several people suggested. If you stick them in with any form of adhesive they will never come out again. Sorry to be blunt, but you don't have to re-invent the wheel for every little job, the tried and tested methods work.

Butyl tape or butyl in a cartridge for fixing the assemblies to the boat, seals from seals direct or similar between the acrylic and the frame.

 

[GregOddity]

You are making a meal of this. It's simple, stick them in with butyl, like several people suggested. If you stick them in with any form of adhesive they will never come out again. Sorry to be blunt, but you don't have to re-invent the wheel for every little job, the tried and tested methods work.

Butyl tape or butyl in a cartridge for fixing the assemblies to the boat, seals from seals direct or similar between the acrylic and the frame.

I’m also sorry to be blunt but I really do not want to have my windows come out AGAIN or to develop leaks. And if I do, I’ll use what every other industry uses and cut the sealant with a thin wire.
How many times did you have your windshield in your car come out AGAIN because of leaks? Or the windows in your house?
And tried and tested by WHOM?

The point of this thread is to actually sift thought the “tried and tested” methods of constant leaks, what primer should you use for GRP acrylic or GRP Aluminium or Aluminium GLASS? How thick should the bead be? 2 mm like in high temperature induction stoves or fill it to your heart contempt? In my marina there must be a bad case of untried and untested methods because there are a lot op people carrying silicone and butyl rushing to plug leaky windows so they can launch this weekend.

 

[PaulRainbow]

I’m also sorry to be blunt but I really do not want to have my windows come out AGAIN or to develop leaks. And if I do, I’ll use what every other industry uses and cut the sealant with a thin wire.
How many times did you have your windshield in your car come out AGAIN because of leaks? Or the windows in your house?
And tried and tested by WHOM?

The point of this thread is to actually sift thought the “tried and tested” methods of constant leaks, what primer should you use for GRP acrylic or GRP Aluminium or Aluminium GLASS? How thick should the bead be? 2 mm like in high temperature induction stoves or fill it to your heart contempt? In my marina there must be a bad case of untried and untested methods because there are a lot op people carrying silicone and butyl rushing to plug leaky windows so they can launch this weekend.

My boat is 38 years old, no leaky windows. They are fitted with the correct materials. The ones you see scurrying around the marina are those that thought they could use bathroom sealant, no more nails, snot, or whatever else they could lay their hands on.

 

[pvb]

You are making a meal of this. It's simple, stick them in with butyl, like several people suggested. If you stick them in with any form of adhesive they will never come out again. Sorry to be blunt, but you don't have to re-invent the wheel for every little job, the tried and tested methods work.

I have to agree, butyl would be fine. What surprises me is that they're messing about with the windows now. I'd have left them until much later in the build. Presumably they're going to line the cabin sides in some way; fixing the windows now just means they're going to have to undo and refasten hundreds of screws a second time to fix the lining under the inner frames.

 

[GregOddity]

I have to agree, butyl would be fine. What surprises me is that they're messing about with the windows now. I'd have left them until much later in the build. Presumably they're going to line the cabin sides in some way; fixing the windows now just means they're going to have to undo and refasten hundreds of screws a second time to fix the lining under the inner frames.

There is no lining coming there. there will be a second frame to cover the insulation of closed cell foam then hard liner vacuum formed. The surface will be raised 4cm over hull.

 

[GregOddity]

My boat is 38 years old, no leaky windows. They are fitted with the correct materials. The ones you see scurrying around the marina are those that thought they could use bathroom sealant, no more nails, snot, or whatever else they could lay their hands on.

Well I'm a newbie to windows, but my next door neighbour is a mechanic and 3 weeks ago had a stone on his windscreen, when I asked how he was going to do it he replied that he was not even going to touch it, he was going to let professionals do the change because he did not want any leaks on his car. He is a hell of a mech with over 40 years’ experience. I heard him.
Since I'm going to do it myself, I listen to advice given, then I ask the Professionals and manufacturers of the products to be used and only then will I actually decide on what and how.

The company I went to were nice enough to even show me how I should fit the rubbers and how the process should work. I don’t see anything fundamentally wrong in asking the manufacturers of said products to explain them and advise on best techniques due to the different materials to be bonded.
I cannot reinvent what I don’t know. But I can learn and do it right. ONCE instead of 3 x
And ask I will.

 

[PaulRainbow]

Well I'm a newbie to windows, but my next door neighbour is a mechanic and 3 weeks ago had a stone on his windscreen, when I asked how he was going to do it he replied that he was not even going to touch it, he was going professionals do the change because he did not want any leaks on his car. He is a hell of a mech with over 40 years’ experience. I heard him.
Since I'm going to do it myself, I listen to advice given, then I ask the Professionals and manufacturers of the products to be used and only then will I actually decide on what and how.

The company I went to were nice enough to even show me how I should fit the rubbers and how the process should work. I don’t see anything fundamentally wrong in asking the manufacturers of said products to explain them and advise on best techniques due to the different materials to be bonded.
I cannot reinvent what I don’t know. But I can learn and do it right. ONCE instead of 3 x
And ask I will.

Cars have nothing to do with it, you're building a boat, are you fitting it with wheels ? If you are assembling the frames/acrylic following advise from seals direct then that's good, don't use bonding products. When you fit the assembled unit to the hull, use butyl. It never sets, therefore stays flexible and if done correctly it won't leak. No need for primers and adhesives/bonding. Should you need to remove the assembly it will carefully prise out. Don't think boat portlights stay put and last forever, the acrylic can get scratched or crack and it will suffer UV damage and need replacing.

The bonding used in car windscreens makes the screen hard work to remove. Yes, you can use a wire, but you can get the wire behind the screen and use a sawing action to do it, that won't be easy/possible on a boat. I'm very well versed in car glass bonding, having spent many years in the motor trade. I have removed and refitted many screens and it's not something i'd want to do on a boat with the type of portlights that you have.

 

[GregOddity]

Cars have nothing to do with it, you're building a boat, are you fitting it with wheels ? If you are assembling the frames/acrylic following advise from seals direct then that's good, don't use bonding products. When you fit the assembled unit to the hull, use butyl. It never sets, therefore stays flexible and if done correctly it won't leak. No need for primers and adhesives/bonding. Should you need to remove the assembly it will carefully prise out. Don't think boat portlights stay put and last forever, the acrylic can get scratched or crack and it will suffer UV damage and need replacing.

The bonding used in car windscreens makes the screen hard work to remove. Yes, you can use a wire, but you can get the wire behind the screen and use a sawing action to do it, that won't be easy/possible on a boat. I'm very well versed in car glass bonding, having spent many years in the motor trade. I have removed and refitted many screens and it's not something i'd want to do on a boat with the type of portlights that you have.

But I am going to do it exactly like you described, It's on the first post. but my issue is not acrylic, I have tempered glass that I need to bond to aluminium.
I’m also considering bonding it permanently but! that is why I am researching what’s being done and what are the materials used and advantages.
So far I’m inclined to go as described on the first post and as Seals + Direct explained and demonstrated.

It's the Glass pane to the Inside of the Aluminium frame that I need to bond permanently. Inside the channel on one side, the inner side. Underneath there will be closed cell neoprene on the bottom of the fame channel where the glass nests and on the outside of the glass then the rubber

 

[ghostlymoron]

I don't understand how you're planning to do it. Assuming you have an 'h' section aluminium window section you should use a rubber 'u' section between the glass and the frame and then seal the frame to the cabin with butyl tape. The frames are usually split horizontally and the two parts joined by fish plates.
The last window of this type I refurbished, I found the glass was sealed into the frame with Sika or similar and it was a right pain to get it out.

 

[PaulRainbow]

I don't understand how you're planning to do it.

+1

Perhaps Greg could post a pic or two of what he has ?

 

[GregOddity]

+1

Perhaps Greg could post a pic or two of what he has ?

For some reason Im having trouble posting pics. let me see if I can sort this out then Ill post it

 

[tonkatoy87uk]

I have an Arvor 25 2002. Im having great troubles with window leaks. Due to the design of the boat, the roof has to come off for them to be replaced so I cant take them out to reseal them correctly. I'm havging to bodge my round it. Ive tried sealent around the edges of the frames inside and out, still leaks so took all that off. then tried ct1, same story. next up will be a shit load of sikkaflex.

I think water is getting inbetween the actual frame itself but cant get in to seal it up
any other suggestions?

 

[GregOddity]

I have an Arvor 25 2002. Im having great troubles with window leaks. Due to the design of the boat, the roof has to come off for them to be replaced so I cant take them out to reseal them correctly. I'm havging to bodge my round it. Ive tried sealent around the edges of the frames inside and out, still leaks so took all that off. then tried ct1, same story. next up will be a shit load of sikkaflex.

I think water is getting inbetween the actual frame itself but cant get in to seal it up
any other suggestions?

You can call Mr Phil Howard from Seals Direct and he will walk you through the options you got. Like I said on the first post I had to start there 'cause I was lost in the wild with our windows as well.
http://www.sealsdirect.co.uk/shopping.asp?intDepartmentId=4#22 you’re probably also going to need something like this on the frame. But you need them to advise you. when I first looked at it I was almost going the same way of Sicaeverything ... his phone is 08452263345
and with your windows if you fail to do it right sicaflex is not going to solve it. My front windows are not as big as yours but were my main concern as well. That’s were this all started.

in my case i will need to use a rubber seal on the outside between the frame and the glass to make it watertight.

 

[pvb]

There is no lining coming there. there will be a second frame to cover the insulation of closed cell foam then hard liner vacuum formed. The surface will be raised 4cm over hull.

I'm sure that will look attractive.

 

[GregOddity]

I'm sure that will look attractive.

It better or the wife will kill me with a rusty spoon.