I prefer SikaFlex, sandable, paintable and even good under water. East to remove if/when required.

 

I'm sure sikaflex works great but Im not a fan because its still a curing sealant. They are messy to work with, once the seal is broken it has to be redone, and its expensive.

I bought the butyl for $5 a roll and it did all of my windows. $5. It is non toxic and super easy to work with because it has the consistency of ABC (already been chewed) gum. The thing I like about it the most is that if the seal breaks for some reason, it reseals itself the next time it heats up.

 

I agree. Great job!

 

Thank you for providing this information. I really need to do this to two windows in my boat.

I have built several HDPE lined pits and used black butyl tape for the liner, which last 15 years without leaks. I never considered using it for the windows.

I am ordering my supply of white or grey butyl tape.

Thanks Rochelle

 

Just realized I posted this in general discussion, maybe it belongs more in the gear and maintenance forum? That is where I meant for it to be. Oops

Feel free to move it

 

Nice job and perfect timing as I am going to be doing this with all of my ports after the end of the season.

 

Looks great and it appears easy enough to do, thanks for the tip

 

I'm not sure how well the butyl is going to adhere to the smooth glass, especially in cold weather. If it bonds well in all temps then that is an easy way to reseal ports. I used Dow Corning 795 which is an industrial glazing adhesive. Faster (mod here on SN) recommended it and it's an excellent product. As big a job as it is I wouldn't want to experiment.

 

Don't think of butyl as bonding like an adhesive, it doesn't. Think of it as a rubbery type substance that never hardens and seals only by the pressure of being bolted between components.

It can break it's seal if not sandwiched under consistent pressure of a through bolted/sandwiched between two items application. It doesn't shrink in cold.. it just gets stiff. If it does develop a leak in cold, a heat gun and a very slight tightening of the fasteners will remedy the situation unless too little for the application was used or too much was squeezed out during the initial install and tightening of the fasteners.

With butyl, even when you have a repair/small leak issue - it's so easy to remedy and fix/work with, there really is no comparison to goops that cure and age.

 

Understood Chris, I use butyl for all my deck hardware but making a water tight seal on glass is extremely difficult, especially since the different materials expand and contract at different rates. I'm just saying that between the frame and the glazing there isn't generally a great deal of compressive force and I'm not sure using butyl is the best material for this application. I may be wrong, maybe Mainesail, who got us all started using butyl, will chime in here with his experience. Re-sealing ports is a time consuming job, not something you want to have to do more than once.

 

Butyl is used by many auto manufacturers to seal windshields. It is laid down, the windshield is placed on top then a secondary seal typically made of rubber and metal is fastened into place using mechanical fasteners or adhesives.

Butyl seals glass with no issues as long as there is pressure applied which is why I used it. When I originally looked into using it I contacted a glass shop who told me that they use it to bed glass into aluminum window frames. my frames are aluminum. Trust me when it was not easy to squeeze those 2 pieces of frame together and the pressure is held by the four screws holding the frame together.

Hopefully this addresses your concern.

 

Good point, mine were all through bolted and I could adjust/apply pressure fairly precisely - not all (not most prolly) ports are like that. Still though, it'd be a tough call as even when butyl does develop a leak, it's so much easier to repair. Any curing goops would necessitate a total removal of all the old material, new surface prep and a full re install whereas butyl can be fudged with with a heat gun and some manipulation right in the trouble spot.

I don't know what would actually be best for a light pressure application like some ports would apparently be. Tough call I guess.

Mine (well, some other guys now..)

 

Butyl it is from now on for all ports and windows!