Core Repair Under Cowl Vents

[rmbrown]

So first, let me set the scene...  My cowls were not mounted in a dorade box or even using a plastic cylindrical dorade.  This is a problem, but not the basis of my question.

I plan to replace the cowls with marinco day/night solar vents, but prior to making that decision, I thought I might just try to rebed the old ones and deal with the lack of dorade.  What I had on the deck was a teak ring, maybe 1.5" tall and the deck plate into which the cowl threaded was mounted in that ring.  4 screws went through that plate and ring and into deck to hold it in place.  The bedding apparently long since gave up the ghost, and the teak ring had split along the grain, both allowing water to penetrate into the deck and rotting out the core surrounding them.  My first indication of a problem was dripping from the teak ring mounted inside the boat supporting the screen.

When I removed the inner ring, I could see a split in the fiberglass tube where the deck had swollen when wet maybe just swelling with the water, maybe with freezing of that water, not sure.

I removed the cowls, deck plates and rings, covered with plastic and duct tape, and sprayed the heck out of the surrounding area (traveler bar included) to see if the cowl deck plate screws were the source of the water or just where it ended up.  The area stayed dry, so I'm going with my theory that the four screws were the source of the water.

I have new deck plates and screws but first have repair at least some of the bad core... which is actually what I have questions about.

I'm trying to determine how much glass, if any, to cut out, or whether to just overdrill, fill with epoxy, and redrill for through bolts when I replace.

Thoughts, recommendations, horror stories and constructive criticism all welcome. :)

[glennd3]

I am thinking drill and epoxy, the solar vents are wide and will cover your work. Would not think there is much load on the deck there unless the rot got to the traveler "tower".

[KWKloeber]

IIWMB I'd want to determine how much if any is rotted. How do you answer the question w/o knowing that?

[Noah]

Ok Ken, first tell me/us what the heck "IIWMB" means...?

[KWKloeber]

OH C'MON.  I learned that frum Stu.

[Noah]

And????

[mdidomenico]

i can't comment on the split, although i can say mine are cracked in the exact same place much less severely though.  i do want to caution you on the marinco vents.  i bought one last year during the defender sale, it only last a year before the motor started getting wonky.  and it's nearly impossible to disassemble, so fixing it is nigh impossible.  i thought it might be better then the oft mentioned failed nicro vents, but doesn't seem like it.

[Noah]

Solar vents:
I believe that Marinco bought out Nico Fico and the vents are supposed to be the same—but they are a poorer quality product than they used to be. You can change the batteries and can buy a generic battery replacement online, but the motor bearings eventually wear out after 3-4 years.

On your repair options:
It is a tough area to work on due to the raised hollow pedestal that supports the cowl blocking deck access. And as Glenn said, close proximity to the traveler tower which need to have a strong deck core underneath. I recommend you dig sideways through the tube crack at deck level from bellow (as well as you can) to a see how far the rot goes. You may need to also do some cores/drill exploratory surgery down through the deck and nonskid and/or up from inside to test creep/damaged area of soft core. Once scope of bad area is determined, then go about deciding whether it can be solved by stuffing-in bits/pieces of replacement core material and mish-mash of fibers and thickened epoxy.  Just drilling and injecting epoxy blind could lead to a substandard repair. 

[Jon W]

IIWMB - If It Were My Boat

[KWKloeber]

Thanks Jon, YBM2I.

FWIW, here's a 30-er who replaced his vent.  He felt the "new quality was quite good.
https://groups.io/g/Catalina30/message/103044

[Noah]

Maybe he wasn't aware that the Night and Day Solar vents come in two sizes; 3-inch hole and 4-inch hole. In addition to my firsthand experience with my vent(s), There is plenty of writing on the Internet complaining about the motors/bearings not lasting as long as the originals.

[Jon W]

I give, what's YBM2I stand for.

[KWKloeber]

U beat me 2 it 

[Robert Mann]

IIWMB (it took me awhile too!) I would do what I did when I found the leak under my main hatch.  Get the longest sawzall blade, that you can get into the core, from Home Depot and the Milwaukee handle for it. Dig out the rotten core and see if you can find the bottom of the rot.  If you can, get a heat gun and dry the remaining non rotted, but wet, core out.  Then get some balsa core (mine came from Defender) and follow Ken's advice to me on how to figure out the shape of the new core required and epoxy the stuff in place.  If you look at my post, which I think was Hatch Issues on Mk2, or something like that, earlier this year, I added some photos of the weapons of mass destruction that I used and the finished product.  Of course the hatch opening had more space to work.  If you can't dig the core out or find the extent of the rot I can only recommend a drill and work outwards from the underneath to find non rotten core, and after that an oscillating tool to cut out the headliner and then replace the core and then replace the cut out piece of headliner. I would prefer not to cut up the non-skid as matching it afterwards could be a chore, but working with epoxy from the underneath ain't no walk in the park either.

[KWKloeber]

Another thought. And that's all these are not being hands-in or seeing pics, is if the vent will cover some of the rot, is drilling where it will be covered to inject epoxy to infuse what's there and/or what you replace.
There's many ways to attack it but without more definition and how much (extent) that's bad these are just possible routes.