Which window sealant ?

[CPD]

I have a 1987 Beneteau First 345 and want to replace the Windows. Hopefully the current configuration can be seen here :



It looks like the (original) perspex is sandwiched between frame and boat structure with Interscrews holding the whole together. The current Interscrews will have to be drilled out. What sealant should I be using on the boat/perspex and perspex/frame interface ?.

Thanks as ever ......

 

[MoodySabre]

Either Arbomast Butyl in a cartridge (I used grey) which was recommended to me by Houdini when they reglazed the frames or a butyl tape.

If your windows are flat then get a price for tinted toughened glass. They were no more expensive than Perspex ( which may now be cheaper since the oil price dropped). The advantage is no more crazing.

Some here will say it's a DIY job to make your own but I know you!

 

[ghostlymoron]

I refurbished one of my windows which was of similar construction using PU40 to seal the glass into the frame. It was entirely satisfactory. I bedded the frames to grp using butyl tape from the local caravan shop.

 

[Alpha22]

Abormast BR - Its what all the professionals use.... it is Butyl sealant in a cartridge. Put lashings on... it squeezes into every gap then clean up with paper towel and white spirit. Job done!

 

[GrahamM376]

When I spoke to the makers, they said Arbosil 1096 which is a glazing sealant. Has worked OK for around 8 years so far. http://www.arbo.co.uk/?s=1096&submit=Search

 

[macd]

clean up with paper towel and white spirit/QUOTE]

White spirit, or anything similar, is not a good idea for cleaning butyl from acrylic, although probably OK on the surrounding fibreglass. Olive oil is OK (although a bit laborious).

 

[LadyInBed]

I was going to suggest Gutter sealant, which is what I use.
I looked up 'Butyl sealant' and see that it's the same thing! :encouragement:

 

[davidpbo]

We used Butyl tape on our Jenneau Tonic but it is a different construction with perspex directly onto the cabin walls without a frame. We also sourced and used stainless interscrews but I probably would not do so again.

The cabin side windows have a slight curve and the front a more pronounced one. The length of the screw to go into the socket has to be fairly precise meaning we had to use some 4mm threaded bar to pull the perspex in then replace with fairly accurately measured and cut machine screws.

If I was doing it again I would consider machined screws and stainless steel locknouts, then carefully (Watching the ammount of heat generated) go round with a cut off wheel on a Dremel drill or similar to cut the thread off flush.

 

[pagoda]

I have a 1987 Beneteau First 345 and want to replace the Windows. Hopefully the current configuration can be seen here :

View attachment 58815View attachment 58814

It looks like the (original) perspex is sandwiched between frame and boat structure with Interscrews holding the whole together. The current Interscrews will have to be drilled out. What sealant should I be using on the boat/perspex and perspex/frame interface ?.

Thanks as ever ......

Our Jeanneau of similar vintage had anodized interscrews. Some unscrewed as designed, about 1/3 of them twisted off in the process, which was fairly handy since the remnants could be pushed out - or in!. Once the old window was out, we used it as a template for the new pane. 8mm lexan. Tough, but not too difficult to deal with. Rough cut with a fine toothed hand saw, then smoothed off the edges with a pad sander. Drill holes carefully, remove any burrs.
We used thin closed cell foam as a seal, with a thin smear of RTV (like an engine gasket...) Works fine.
The alloy interscrews we binned. Replaced by socket/ button headed new M5 interscrews in A4stainless , with nylon washers under the head on the outside. They will not corrode to dust. Finding interscrews in A4 took some effort (and about £65!). Don't consider starting the job unless you have weather to finish it!

 

[MoodySabre]

I have a 1987 Beneteau First 345 and want to replace the Windows. Hopefully the current configuration can be seen here :

View attachment 58815View attachment 58814


It looks like the (original) perspex is sandwiched between frame and boat structure with Interscrews holding the whole together. The current Interscrews will have to be drilled out. What sealant should I be using on the boat/perspex and perspex/frame interface ?.

Thanks as ever ......

Alan - what does the inside look like? Moodys look like that on the outside but there is an internal frame as well into which the screws fix, through the topsides of course. So just screws not inters.

 

[charybdis55]

I have a 1987 Beneteau First 345 and want to replace the Windows. Hopefully the current configuration can be seen here :

View attachment 58815View attachment 58814

It looks like the (original) perspex is sandwiched between frame and boat structure with Interscrews holding the whole together. The current Interscrews will have to be drilled out. What sealant should I be using on the boat/perspex and perspex/frame interface ?.

Thanks as ever ......

Hello, some years have past since your post but you may be able to advise me on your experience?

I have a 1983 Beneteau Idylle and looking at your photo it has the same window design. I need to renew the Perspex in all four windows and wondered where you got the A4 stainless interscrews from? Also, what sealant did you use between the Perspex and hull?

Lastly, when drilling the Perspex for the interscrews, what size drill bit did you use? I've been advised the holes need to oversize to allow the Perspex to expand and contract.

Thanks in anticipation