acrylic windows

[skipper681]

My sailing boat has leaking windows, I'm thinking of covering the two windows (on each side) with one long tinted acrylic window stuck in with sikaflex UV

Is this a good idea or should I just get the rubbers and keep it standard.

Are there pros and cons to each senario?

 

[VicS]

My sailing boat has leaking windows, I'm thinking of covering the two windows (on each side) with one long tinted acrylic window stuck in with sikaflex UV

Is this a good idea or should I just get the rubbers and keep it standard.

Are there pros and cons to each senario?

with hind sight when I assembled my boat I would have cut the window openings smaller than the windows supplied and bolted them on using a suitable sealant rather than use the rubbers.

Some of the very last boats produced had single piece windows and a few have been retrofitted.
I don't like them.

I'd not rely on Sikaflex alone but I suppose modern car windscreens etc are just stuck on.

Remember that the stuck on windows will have to overlap the sides all round so will be significantly larger as well as being in one huge piece.

 

[skipper681]

If anyone's done this is there a recommended company that can make the windows from say a cardboard template?

 

[Tranona]

Local signmaker is best bet. Consider polycarbonate rather than acrylic. If you can't find anybody locally (unlikely) then google boat windows and you will get several suppliers.

 

[pvb]

I also reckon polycarbonate would be preferable to acrylic. There's an interesting article here on how to stick windows on without making too much mess!

 

[VicS]

If anyone's done this is there a recommended company that can make the windows from say a cardboard template?

Several in the S.East and Solent areas ( Hadlow Marine , Seaclear windows, Project Plastics, UK Plastics Fabrication Ltd, Sunlight Plastics ) but I dont know of any in NI.

Nearest that I know of will be Eagle Boat Windows in Lancashire.

Polycarbonate is stronger, its what riot shields are made of, but Acrylic is a little more scratch resistant.

For a small boat acrylic will be adequately strong, and probably a little cheaper.

Polycarbonate is more prone to solvent damage, although acrylic is by no means immune.

Shop fitters and sign makers may be less likely to have the tint colours usually used for boat windows in stock.

 

[skipper681]

thanks for all the replys, I think I'll go with acrylic, even though we're not short of a riot shield or two over here lol.

 

[30boat]

The larger the window the more it will expand.The more it expands the more stress is put on the sealant and fasteners.Acrylic,especially tinted acrylic,expands a lot with heat from the sun so smaller windows are less likely to stress the mating faces.In my experience sticking acrylic windows with Sikaflex like sealants is a hit and miss affair.You need to allow for movement if you expect the window to remain leak free.I always drill oversize holes for the fasteners and don't countersink them.I apply a bed of sealand that I allow to half cure before putting a fresh layer of sealant and only then I fit the acrylic.The fasteners are only fully tightened(but not too tight) a day or so later.This way there's a thickness of sealant that acts as a gasket that if there's a leak can be compressed by tightening the fasteners making everything watertight again.

 

[maxi]

Polycarbonate is stronger than Acrylic, but scratches very readily and is, I believe, more susceptible to UV damage.

As for sealants, I have never made any sealant adhere for much more than 3 years, despite extreme care with the surface preparation. It is always the seal to the Acrylic that fails, never the seal to the grp.

I have recently spoken with a prominent sealant supplier regarding Perspex Primers, and he says that; whilst these are available he thinks that they are of little benefit !! If anyone has a bombproof system of getting sealant to attach permanently to perspex, please share the secret.

By the way, Hadlow Marine Services who specialise in marine windows, recommend EHB double sided tape with the threat: "get it right first time because you will not get a second chance to realign your window" - sounds good to me.

 

[MoodySabre]

To avoid future crazing and scratching I had my windows reglazed with tinted toughened glass by Houdini. They look superb and glass is slightly cheaper than perspex.

I had some perspex washboards made by Hadlow and they are very nicely made.

 

[pvb]

In my experience sticking acrylic windows with Sikaflex like sealants is a hit and miss affair.You need to allow for movement if you expect the window to remain leak free.I always drill oversize holes for the fasteners and don't countersink them.

The article I linked to previously recommends not using fasteners at all, and sticking the windows on with 3M VHB tape, then just using silicone sealant to tidy and seal the edges.

 

[30boat]

The article I linked to previously recommends not using fasteners at all, and sticking the windows on with 3M VHB tape, then just using silicone sealant to tidy and seal the edges.

Yes but can they assure that tape alone is enough?How long will the windows stay attached?

 

[pvb]

Yes but can they assure that tape alone is enough?How long will the windows stay attached?

The article says it's the stuff used by car makers to stick cars together...

 

[skipper681]

The larger the window the more it will expand.The more it expands the more stress is put on the sealant and fasteners.Acrylic,especially tinted acrylic,expands a lot with heat from the sun so smaller windows are less likely to stress the mating faces.In my experience sticking acrylic windows with Sikaflex like sealants is a hit and miss affair.You need to allow for movement if you expect the window to remain leak free.I always drill oversize holes for the fasteners and don't countersink them.I apply a bed of sealand that I allow to half cure before putting a fresh layer of sealant and only then I fit the acrylic.The fasteners are only fully tightened(but not too tight) a day or so later.This way there's a thickness of sealant that acts as a gasket that if there's a leak can be compressed by tightening the fasteners making everything watertight again.

That makes a lot of sense, I was going to make some sort of 3mm filler but never thought of using the actual sealant. Thanks for the advice.

 

[Slinky Spring]

Eagle boat windows

http://www.eagleboatwindows.co.uk/

I used this company. Very satisfied. Gave good advice as well.

 

[skipper681]

http://www.eagleboatwindows.co.uk/

I used this company. Very satisfied. Gave good advice as well.

Thanks Slinky, I've just rang them and can confirm they definately know what they're talking about, I'll be sending a template off to them, so that's the supplier sorted.

 

[savageseadog]

The biggest strain on the window seals may be when the boat is lifted.

 

[skipper681]

Thanks Sava but it's only 19ft, I'll trailer it probably.

 

[GrahamM376]

Seaclear supplied Weatherseal tape (thin layer of closed cell foam) for bedding our ally frames to the coachroof. Only sticky on one side so needs bolts as well but, after 3-4 years in warm climate no leaks so far. Should work on acrylic as well.

 

[misterg]

That makes a lot of sense, I was going to make some sort of 3mm filler but never thought of using the actual sealant. Thanks for the advice.

If you can cope with having fixings, the flexible butyl tape is excellent.

See:

http://www.ybw.com/forums/showthread.php?p=3756989#post3756989

Andy