Any Reports of Bonding Problems (leaking) with Catalina Windows - Post-2020?

[VFR750]

Anyone else had/is having problems with their post-2020 Catalina side windows de-bonding and leaking?

I heard that there was a widespread issue with post-COVID boats delivered with bonding issues. Catalina shipped a lot of spare windows (all models) to dealers. There was talk of bad batches of adhesive post-COVID, or bad technique, or the wrong adhesive used.

I was told Catalina Yachts used Sikaflex.

My Experience has not been good:

My 315 was built in the summer of 2023. Upon delivery in September 2023, both large bonded windows were not fully attached.

Catalina Yachts paid for them to be replaced.

In the Spring of 2024, they dis-bonded again. Then re-bonded in June 2024, with screws added at the front, mid, and rear ends. Again, this was covered.

This worked until 2025, when I had to re-seal just the front edges with Sikaflex 295 UV, and again in April 2026.

Now it's Summer 2026 and the windows are leaking again, and Catalina Yachts is kaput; no more warranty.

I'm probably looking at a full window replacement again. on my dime.....

Anyone else having this problem?

 

[duality]

your using the wrong sealant. i redid mine and catalina instructed to use dow 795,

Fixed Port Windows

I know there are a lot of articles posted on the subject on different suppliers web sites, but I wanted to ask if anyone has actually taken on and documented the process of replacing the four (4) Plexi / Lexan windows our our C-310's? Being frame-less and fastener free, they differ from some...

forums.sailboatowners.com

good luck

 

[VFR750]

Interesting comment on Dow 795.

I’ve been researching this and even SIKA (on their website) cautions against Sikaflex 295 where you have transparent windows, unless you use their opaque tape to shield the bond.

It seems 795 is totally different, as it is silicone, not polyurethane.

And I am thinking that is the better choice.

That’s why I’m asking here about others recent experiences on their Catalina’s

and did Catalina Yachts change the adhesive in production to Sikaflex from 795?

my other data point was my 2008 22 Sport. Those 15+ year old bonded windows never leaked!

 

[Stu Jackson]

and did Catalina Yachts change the adhesive in production to Sikaflex from 795?

You might want to begin to recognize that it simply doesn't matter. Really. I'm torn between not wanting to sound harsh vs. sounding like your mother. As you say, CY is gone. YOU are the guy with the boat that needs repair. So, fix it.

You've come to the right place to "do your research." The very first answer you received is the correct one:

your using the wrong sealant. i redid mine and catalina instructed to use dow 795,

You can keep researching, but this answer is the one you will find is the correct one to apply to your issue.

Good luck, it's very repairable using the right material and will work for decades.

FWIW, I bought my 1986 boat from its previous single owner in July 1998. That September, in a rainstorm at anchor at Angel Island in SF Bay, my fixed port on the port side started leaking, big time, right over the nav station and electrical panel. I went out, pulled it up, squirted silicone into the gap, pushed it back in and tightened the screws. It's been fine ever since (28 years!). I mention this only to note that older Catalinas used screws in addition to sealant. I didn't know any better back then in the leak emergency and wouldn't use silicone on my boat ever again. In fact I banned it from use anywhere on my boat except for the Beckson opening ports where it is the only material recommended by Beckson. Your research will find Catalinas with screws on fixed ports, you could choose to add them to yours in addition to the proper sealant. You will learn how to carefully drill and dress the holes. Good luck again.

 

[BigEasy]

I don’t own a Catalina; however, acrylic is acrylic & gelcoat is gelcoat no matter how you slice it! The Achilles heel on many Beneteau’s is the deck mounted skylight panel. I have resealed mine several times using Beneteau’s recommended procedure once, Sikaflex once, & 3M VHB double sided adhesive tape + DOW 795. Beneteau’s adhesive provided a leak proof seal for approximately one year, Sikaflex was leak proof for a few months & began to mildew & discolor quickly, and finally, my last repair with 3M tape + DOW 795 is holding up well after 4 years. The double sided tape provides the adhesive strength & Dow 795 provides a tenacious seal around the perimeter. Check out Andy’s video on Boat Works Today for the procedure port light lens with VHB tape & Dow 795.

 

[VFR750]

Stu,
From the DOW website: What is DOWSIL™ 795 Structural Glazing Sealant? A one-component, neutral-curing silicone sealant

I know I have to replace the window.

But the point of the post was: I wanted to know if my issue was unique or common.

 

[VFR750]

I don’t own a Catalina; however, acrylic is acrylic & gelcoat is gelcoat no matter how you slice it! The Achilles heel on many Beneteau’s is the deck mounted skylight panel. I have resealed mine several times using Beneteau’s recommended procedure once, Sikaflex once, & 3M VHB double sided adhesive tape + DOW 795. Beneteau’s adhesive provided a leak proof seal for approximately one year, Sikaflex was leak proof for a few months & began to mildew & discolor quickly, and finally, my last repair with 3M tape + DOW 795 is holding up well after 4 years. The double sided tape provides the adhesive strength & Dow 795 provides a tenacious seal around the perimeter. Check out Andy’s video on Boat Works Today for the procedure port light lens with VHB tape & Dow 795.

Thank you. I just watched the video. I've heard of this tape. I like this!!

Wow, I'd get one shot with a 7 foot window!

 

[BigEasy]

Trick to using 3M VHB tape is to trial/dry fit the lens & mark the lens position with painter‘s tape or marker pen. I also used 3M primer to enhance the bond. You only get one chance to position the lens correctly! Once the lens & tape makes contact to the gelcoat, you can’t reposition it. Once it makes contact, you’re stuck, for better or worse!

 

[BigEasy]

Your research will find Catalinas with screws on fixed ports, you could choose to add them to yours in addition to the proper sealant. You will learn how to carefully drill and dress the holes. Good luck again.

Stu,
How did Catalina prep the acrylic lens with screws to prevent stress fractures in the acrylic? With thermal cycling affecting the dimensional stability of the lens, what method(s) were used to compensate? Was the hole size drilled slightly larger than the screw, was a flat head screw used with a nylon washer, was a grommet used between the lens hole & screw, and finally, how close to the edge of the lens were the screws placed. It would be a bummer to place new lenses & have them fracture because of improper installation.

 

[Stu Jackson]

Stu,
From the DOW website: What is DOWSIL™ 795 Structural Glazing Sealant? A one-component, neutral-curing silicone sealant

I know I have to replace the window.

But the point of the post was: I wanted to know if my issue was unique or common.

In layman's parlance for boaters, silicone has always been the cheaper stuff (or more expensive Sikaflex) in small tubes or larger cartridges and was usually whitish. Over the years it became known as the bane of boaters because it was often incorrectly applied and later because improved products became available, like BedItWithButyl. Dow795, while a silicone based product, is a specialty item used for glazing in boats and architecture.
Unique or common to post-Covid boats was not a particularly emphatic point of your post, but upon re-reading I apologize and see what you mean.

How did Catalina prep the acrylic lens with screws to prevent stress fractures in the acrylic?

Big, my boat came with screws no washers of any kind When I had my rainstorm adventure I wasn't looking at them in detail as you can imagine and haven't bothered with them since, nor needed to. No finishing washers, although I've seen some, don't know if owner or factory installed, don't know if factory ever installed finishing washers. I've seen photos of some though. My boat had countersunk screws, not flat head, so the hole was "dressed" for them.
My boat has been in SF and BC so maybe not an issue in my environment although it got hot in SF in Sept and Oct, and while I've heard of the expansion issue you mention, I also haven't heard of Catalina 34 boats in say Florida with this issue. Could be dependent on weather. Although in my reading I am somewhat of the opinion it may be an internet myth made up by folks who had more theory than real world experience. In architecture, usually the inside is air conditioned, so the delta T between inside and out is larger than boats.
Over the years Catalina came and went with screws. Most C34s, both Mark Is and IIs do not have screws and it could well be my PO put 'em in.
It wasn't so much how close to the edge, but rather how far could they put the screw to still grab the inside lip of the opening.