Leaking ports

[Wixlandia]

We have the universal problem of leaking fixed ports on a Cheoy Lee Perry 35 (1980). All were leaking at the time of purchase, and seemed to have some kind of ancient putty various sealants bedding the glass.

The fixed ports are installed in a 'sandwich' configuration with a profile cross-section in the attached diagram, with the glass captive between external and internal wooden frames that are attached to the margins of the cutout, but the glass is not unfortunately not directly compressed against the hull in any position. The internal ply fascia has now been replaced, and sealed to the GRP with butyl tape. The wooden frames have been completely stripped and redressed. The glass has been replaced.


Full size https://ibb.co/ckxb7v6

Full size https://ibb.co/kMX2VzB

I am aware that many people have had new frames fabricated from stainless, however the cost is prohibitive at the moment.

At this time, just the internal frames are installed, with butyl tape at B and C, and no signs of leak from B or C at all.


Full size: https://ibb.co/1n4KLcx

The glass sits pretty loosely and the space between external frame (when dry fitted) and glass at D and internal frame and glass at F is quite large about 3-4mm on both sides - i.e. the window is not compressed in place by the frames. Our initial intention was to bed the window with butyl but a temporary fitment with butyl bead placed at at E and F, without the external frames yet applied (shown in the picture taken from inside the cabin) has the window glass slumping to the bottom, and rain already in between glass and internal frame at F.

I figure we need to end up with some kind of gasket style seal bridging D, E and F with the external frame providing some moderate level of compression - but the butyl seems too gooey to do this.

Current plans involve using pieces of butyl tape as 'stand offs' at E to keep the window settled, then copious butyl sealant at F E and D and then maybe butyl tape or PE tape applied to the inner lip of the external frame at D to try to get some gasket style compression... it's not perfect.

We could use a polyurethane sealant, but it'll be so hard to remove or repair in future - and we were keen to find a butyl solution.

Any help or guidance would be greatly appreciated.

Full size images:
https://ibb.co/1n4KLcx
https://ibb.co/kMX2VzB
https://ibb.co/ckxb7v6

[Reefmagnet]

If you search around, you may find a suitably dimensioned neoprene or rubber "u" section extrusion that can be installed as a seal to take up the gaps. I've also used softish neoprene generic round section extrusions succesfully as window seals. They squish down well and form a watertight seal.

[Wixlandia]

Originally Posted by Reefmagnet

If you search around, you may find a suitably dimensioned neoprene or rubber "u" section extrusion that can be installed as a seal to take up the gaps. I've also used softish neoprene generic round section extrusions succesfully as window seals. They squish down well and form a watertight seal.

That's very interesting - so no liquid sealant at all, just the sandwiched extrusion between the frames?

There are many extrusion profiles, which one is closest to what you suggest?

https://www.indrub.com.au/rubber-pro...xtrusions.html

[Singularity]

Also consider looking into 2-sided 3M VHB tape if you're not familiar with it (at least a few threads here and YT videos). High strength and produces a watertight seal, though it seems like you have a few options as to where to use VHB vs rubber extrusion.

[Wixlandia]

Thank you both for the ideas.

The frames are quite irregular in shape and contour, so I don't know if that will affect the seal if a gasket is used.

The tape looks great - but which surfaces would you apply it to? The frame at D and F, or at E?

[Singularity]

My understanding is that VHB is very good when all mating surfaces are flat/in plane, but it isn't a 'compressible gap filler.' So in your diagram, if the inside frame is ~very flat, then applying VHB around the exterior-side of the inside frame ("F" in your diagram)..then placing the window against this 'VHB ring'...at that point you'd have a water-tight and secure window, but then you have gaps "E" and "D" to contend with. You don't want to collect water, but perhaps butyl would be easy enough to fill these voids; butyl being easy enough to remove in the future even if 'better' sealants are available.

I say at "F" because it appears that the inside woodwork is in place; ideally a water seal would be 'most outside' so as to not provide any water traps, while I don't think I'd personally put VHB inside and out (such seems redundant, hell to remove later, and, if not done right, creates water traps you can't get to).

VHB tape is reportedly problematic to remove, so look into that if it's a concern. If getting serious about VHB I'd talk to someone who has used it, with attention on 'how flat' your frame-window geometry is. Hopefully those wiser chime in.

[Discovery 15797]

I like the idea of using butyl tape around the perimeter (D), and use rolled soft butyl to fill the gaps (D and F).

I get my rolls of soft butyl from New Found Metals.

[Spot]

I am having similar issues, 45 year old cracked plastic frames sandwiching acrylic into the port light holes. Wondering if UV-stabilized HDPE would work for making new frames and accepting sealants. There is no plywood liner in my situation.

[Wixlandia]

Thank you to all for the feedback so far - super useful. Yes, the surfaces are irregular, so a liquid product is probably superior. I did not know about the 'U sections' so that is something to research.

Spot - I have seen people 'scan' the original frames and then CNC laser cut them in stainless for that exact problem

[Spot]

Originally Posted by Wixlandia

Thank you to all for the feedback so far - super useful. Yes, the surfaces are irregular, so a liquid product is probably superior. I did not know about the 'U sections' so that is something to research.

Spot - I have seen people 'scan' the original frames and then CNC laser cut them in stainless for that exact problem

Hi Wixlandia, Thanks for the tip. Scanning would be awesome. I have been measuring them and cutting out 'see if they fit' templates on a laser at work. The shapes are rectilinear 24 x 9.375" OD (610 x 238mm) with radii in the corners so it's no too bad, two are rectangles and the other two have one square corner and two tapered sides.
If I use a plastic as the base material, I am looking at 100$ USD plus labor which could be done at home. Moving to metal means 300$ materials in aluminum and 500$ in thinner stainless and will not allow me to complete at home. If the designs were broken into pieces, nested, and fed to a laser or plasma cutter- metal costs would go way down but there would be time in welding and grinding. I have not priced any of that yet.

[Singularity]

Originally Posted by Spot

Hi Wixlandia, Thanks for the tip. Scanning would be awesome. I have been measuring them and cutting out 'see if they fit' templates on a laser at work. The shapes are rectilinear 24 x 9.375" OD (610 x 238mm) with radii in the corners so it's no too bad, two are rectangles and the other two have one square corner and two tapered sides.
If I use a plastic as the base material, I am looking at 100$ USD plus labor which could be done at home. Moving to metal means 300$ materials in aluminum and 500$ in thinner stainless and will not allow me to complete at home. If the designs were broken into pieces, nested, and fed to a laser or plasma cutter- metal costs would go way down but there would be time in welding and grinding. I have not priced any of that yet.

Check out the video below using VHB and Dow 795. Idea is VHB secures the ~glass and provides a little offset (or lift...holding the glass off of the frame/cabin wall exterior) so that Dow 795 is then placed in the gap that is formed circumferentially about the border under the glass and in the offset/gap created when the VHB prevented the glass from touching the cabin wall. This is a common technique...it does away with frames completely but does have a "stuck on window" appearance if the cabin wall/upright has no recess to receive the window. But it is very easy; several threads/YT videos if you dig around. Otherwise the process is less expensive than anything you could come up with and it's routinely weatherproof (but do read on best practices).

https://youtu.be/MQyjxVUskd8

[Spot]

Singularity,
Thanks for the video and suggestion. Some others with my same make boat have also opted for new/oversized glazing adhered to the outside of the hull, even though there are no recesses. More for me to think about...

[Wixlandia]

I haven't been able to find soft rolled butyl in Australia, though I can order butyl tapes online, and buy butyl sealant in hardware stores. We'll try a composite suggestion from above, and try to sandwich the window with the frames and plenty of butyl sealant, with some tape to hold the window in place. Any other ways much appreciated

[Spot]

Hi Wixlandia,
Do the inside and outside frames on the boat share hardware or use separate hardware?
If the outside frames were sealed and fixed in place, could you replace the glazing from the inside?

Thanks for letting me join in on your thread and all the best on your repairs!

[Wixlandia]

Originally Posted by Spot

Hi Wixlandia,
Do the inside and outside frames on the boat share hardware or use separate hardware?
If the outside frames were sealed and fixed in place, could you replace the glazing from the inside?

Hi Spot,

Yes, you could place the glass from the inside if you removed the inside frames, though the angles are much better from the outside as the glass 'sits into' the space.If you affixed the external frames and then glazed from the inside, the glass would try to fall out constantly until you had the internal frames in place.