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Sealing glass into aluminium frames - butyl?

Posted by Morgan 
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Sealing glass into aluminium frames - butyl?
10 May, 2019 12:51
For refitting glass into aluminium frames, is 2 part butyl rubber the best option?
If so, any ideas where I might get some? I haven't managed to find a supplier.

Are there other suggestions for making the seal?
Re: Sealing glass into aluminium frames - butyl?
13 May, 2019 09:51
Hi Morgan,

Others will be more qualified to tell you whether it's the best thing for the job, but I picked up a roll of butyl tape from Wurth on the Ballysimon Road in Limerick last year. I used to reseal my deck stanchions and it worked a treat.

Re: Sealing glass into aluminium frames - butyl?
21 May, 2019 22:11
Re: Tips on How to Repair Leaking Aluminium Boat windows
21 May, 2019 23:09 Registered: 7 years ago
Posts: 47
Maybe this will help

I recently posted a Question and was looking for advice on fixing leaking Motor Boat windows,
I did extensive Internet research, and approached the task with the knowledge gained

I have put together the process I used on one of my more Awkward windows, YES I have more,
Later when I am putting the windows back in Place on the Boat, I will Post this process also. As this is a different process

IMPORTANT Before you start this process you have to understand that pasting Sealant on the outside of the glass or frame is not a solution, this is only temporary and cause more Problems

Repairing my Leaky boat windows

Tips before you start
1. Have a clean uncluttered work area
2. Essential have some one to help, this is not a task that is easily done on your own
3. Mark all the parts before you dissamble
4. Make sure you Put alignment marks so the glass will go back to the exact same Position, in the frame ( I failed to do this on the 1st window and had to take it apart) and this was a very messy task
5. If you can do a dry run
6. Cut 2 blocks of wood with some channels to hold the glass and frame upright, this will make assembly easier
7. Have all tools & Clean rags and Thinner ready NOW, as when you apply Marine Sealant, it has a relatively short setting time
8. You want the Rubber seals to run continuously around the frame, ie only one joint

My Proceedure

1. Remove and clean all parts really well with scraping and wiping with thinners
2. I started by working from the Bottom up, so any rubber Seal butt joints would be at the top of the frame
3. I ran a bead of Marine Silicone into the Rubber U Channel, and then fitted to the cleaned Glass
4. At the corners I cut off the bulging excess Rubber and formed a tight miter type joint, with extra Sealant here to compensate.
5. I ran my hand firmly around the Rubber to squeeze out sealant to the sides of the glass
6. Now apply a small bead of Sealant to each side of the Aluminium channel just at the top edge, this will act as a lubricant to the glass/rubber and when dry a sealant
7. Working from the bottom of the fame upwards I aligned the Glass to the register marks I placed earlier, and tapped lightly with my Rubber mallet to slid the glass into the recess
8. We assembled the 2 sides, and secured the bottom corners with the screws, tapping gently and nursing the rubber into place
9. Lastly we put the longer top piece on and secured the corner screws
10. we placed a set of clamps across the frame as one of the Alu tracks was offering resistance to staying in place, and from the picture you will see how we stopped the clamp from slipping
11. We cleaned up as much of the excess sealant off the glass and track, but this was minimal.
12. when the whole unit was dry the next day we cut back any excess rubber and pared back any Sealant that oozed out.
12A. Job done and we are very happy with result
14. This is a task that I would definitely get better at as I go forward, especially the amount of Sealant that needs to be placed in the Rubber U channel and on the Alu frame.

I know you are probably thinking why do you need Sealant with a Rubber U seal, well 2 reasons that I can suggest are

1. The Sealant actually helps you squeeze in the glass to the Frame, as it acts as a Lubricant
2. The Sealant when set, Holds fast all parts and makes a complete weather tight seal, that will last for many years, Marine sealant is UV Safe and forms a permanent Weather seal between the rubber & Glass and the Rubber and the Aluminium Frame, it is also very Flexible. The sealant we used was Rubber, Glass and Aluminium Friendly

View Images at Link below ........ Scroll down and click on ....... "View Album" []

I hope this is of help to some other boaters, & if you have any questions, you can either PM me or leave a comment.
Re: Sealing glass into aluminium frames - butyl?
27 May, 2019 19:06
Hi Patrick H and Fergus
Thanks for reposting that, the windows are all done about 18 months now and not one leaks.
I did say I would post about rebedding them into the boat, but time got the better of me.
The process for this is a little different.
I used Butyl tape got in Dublin from either of two suppliers, simply "Google Butyl tape Dublin".
In hindsight I would use Semi setting Butyl tape this time if I had to do again, as the Semi setting version comes in a Tube and can be dispensed like Silicone. It forms a skin and wont creep like the standard Butyl tape, as you will have to clean off the excess a few times over a few months with the tape version, it is easy to peel back and clean with white spirit. It really does a great Job and ifs fully reversable, if for any reason you need to remove a window due to breakage over the next few years.
Butyl is a man made rubber, it is fully waterproof and stays tacy for up to 30 years, it doesnt loose it grip and can compress and stretch as the boat moves through lifting and hot and cold flexing.
There are other options, but if you have bolt through windows then this is definitely the product to use.
Other options are Neopreme gasket, Sika Flex, and abro mast, I considdered them all but for ease of working and long no setting time, this allowed me to adjust and move the frames about, as you might have to take a window in and out to adjust something.
Some of the frames can be stubborn to get back into the boat, so this is why good marking for reference before you remove and disassemble is essential

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