What to seal windows with?

[Zagato]

The gaskets for my IF Boat are no longer available (from hAlberg Rassey). I use a classic car window sealing compound in my business for Defenders (not cement type stuff) which is like a black butyl kind of stuff, similar to Dum Dum in a cartridge. Somebody has used some stuff like bathroom sealant which has just shrunk...

 

[johnalison]

I had an opening windscreen section come adrift this year, with the rubber seal parting. I repaired it with a silicone rubber compound from the chandlers. I had been advised to use Dow Corning silicone rubber but this was another brand. Judging by the difficulty I had in scraping the excess off the glass when I was tidying up after it had set, it should do the job well.

 

[Zagato]

Many thanks sounds good. Also been recommended Sikaflex 295 UV but worried it is more of a cement!

 

[northwind]

use buytl, you want a sealant not an adhesive.

 

[vyv_cox]

I fitted glass windscreens to my motorsailer. The fitting kit was as used for VW sliding doors. A primer was applied to the glass, after which the glass was installed using a polyurethane sealant very similar to Sikaflex 291.

 

[stuartwineberg]

use buytl, you want a sealant not an adhesive.

+1 butyl glazing tape. Mst variants of Sikaflex are very permanent

 

[Zagato]

I have been advised by a window refurbished to use Arbosil 1096 which is a silicon rubber for sealing glass into the frame. Not so sure, silicon sealants don,t seam to last long and are a bugger to get out!

To fit the frame to the boat SCAPA 3507/12 bedding seal has been recommended. Again not so sure as it says it is PVC foam and sticks like nothing else. My window frames don't need glueing in position the are screwed in sandwiching the coach roof.

The guy that advises these products does no his business however and the SCAPA stuff may well be butyl glazing tape as described. Takes longer to research all this stuff than to do the actual job sometimes. Just don,t want anything cemented in permanently as nothing lasts forever...

 

[vyv_cox]

My windows were professionally refurbished by a company in Athens. They came highly recommended. When I understood that they used silicone rubber I was dubious but this was a long way from RTV bathroom sealant. The silicone was cured with an accelerant, then the windows were stoved for 24 hours. They have been leak free for 5 years now.

 

[peter gibbs]

Many thanks sounds good. Also been recommended Sikaflex 295 UV but worried it is more of a cement!

This is the stuff, but you must mask up with tape or have hands as steady as Nicola Benedetti. Work it on to the job with a paint spatula but take care the corners are rounded or the acrylic window will scratch. It smears everywhere but remains pliable when cured - about a day.

PWG

 

[Buck Turgidson]

SIKASIL® SG-20

 

[Stemar]

I've tried several things over the years, but the only thing that finally gave me dry windows was bolting Perspex directly to the cabin side with butyl tape in between.

 

[STATUE]

The gaskets for my IF Boat are no longer available (from hAlberg Rassey). I use a classic car window sealing compound in my business for Defenders (not cement type stuff) which is like a black butyl kind of stuff, similar to Dum Dum in a cartridge. Somebody has used some stuff like bathroom sealant which has just shrunk...

I had a similar challenge , took out all the paraphernalia and the window 'glass', then just stuck it back with 3M VHB (Very High Bonding) tape - expensive - but for 5years now no movement, no leaks.

 

[Deleted member 36384]

My window frames are sealed to the hull with the foam tape and have been watertight for over 5 years now.

The foam is as you mention the SCAPA 3507/12, or an equivalent. The tape was the 3 mm thick stuff. It is not sticky. It has a resilience that wants to return to the original shape.

Screw the frames to the hull until you get a small bead extruding. Some of the frames, being straight, have to fit around a slight curve in the coach roof in this case, a bit more force was needed and the bead was a bit bigger.

Clean with thinners or something to degrease GRP before fitting. Windows have been jet washed, green water, torrential rain, not a drop. I have not removed a window so can’t comment on what happens, but it is not a glue, so issues like the sealant adhesives will not be a problem.

The adhesive is on one side only, you stick that side to the window frame.
High Density Grey Foam Scapa 3507 - Shand Higson & Co Ltd

 

[dulls]

The gaskets for my IF Boat are no longer available (from hAlberg Rassey). I use a classic car window sealing compound in my business for Defenders (not cement type stuff) which is like a black butyl kind of stuff, similar to Dum Dum in a cartridge. Somebody has used some stuff like bathroom sealant which has just shrunk...

The grey butyl tape maybe as it never goes off? I have used it at home and will use it on my next boat. You tape and then put pressure on it as you remount the glass>

 

[James W]

I have been advised by a window refurbished to use Arbosil 1096 which is a silicon rubber for sealing glass into the frame. Not so sure, silicon sealants don,t seam to last long and are a bugger to get out!

To fit the frame to the boat SCAPA 3507/12 bedding seal has been recommended. Again not so sure as it says it is PVC foam and sticks like nothing else. My window frames don't need glueing in position the are screwed in sandwiching the coach roof.

The guy that advises these products does no his business however and the SCAPA stuff may well be butyl glazing tape as described. Takes longer to research all this stuff than to do the actual job sometimes. Just don,t want anything cemented in permanently as nothing lasts forever...

The Scapa tape is fantastic stuff. I've used it on a few boats and it's easy to use and works. I'm not entirely sure of the application here though, I used as a gasket between frames and the coachroof GRP.

 

[pawl]

If it's to seal the frame to the hull then I use Abro-BR, it's non setting butyl. It's used in the building trade so you may get it at Screwfix or a builders' merchants. It's a bit messy to use but cleans up with white spirit. If it's to seal the glass into the frame then you will really need some sicaflex type product. I looked into doing this but in my view it is probably best done by a professional.

 

[jamie N]

Perspex Folkboat windows sealed with CT1 clear sealant.
Perfect.

 

[Tamar]

I used a butyl based sealer from Screwfix on my one window which was slightly dripping. A messy horrible stuff, but white spirit cleans it good.
Cleaning the old stuff off was a major job, as it looked like the original , but after two years it's still drip free.

 

[Bornslippy]

I'm replacing the toughened glass in some heavy traditional bronze portholes, probably the first time this has been done in 43 years, and hopefully the only time in my lifetime. They have a thin bronze glazing panel to hold the glass in but it isn't exactly strong - tiny screws. Do I seal the glass externally with sika 291i, with perhaps arbo BR in the joint to make it more likely that it would ever come apart again?

 

[James W]

I'm replacing the toughened glass in some heavy traditional bronze portholes, probably the first time this has been done in 43 years, and hopefully the only time in my lifetime. They have a thin bronze glazing panel to hold the glass in but it isn't exactly strong - tiny screws. Do I seal the glass externally with sika 291i, with perhaps arbo BR in the joint to make it more likely that it would ever come apart again?

If you ever want to remove the glass again without damaging the portholes irrevocably, don't use 291i.