Catalina 34

General Activities => Main Message Board => Topic started by: rmbrown on July 11, 2019, 01:08:14 PM

Title: Core Repair Under Cowl Vents
Post by: rmbrown on July 11, 2019, 01:08:14 PM
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. :)
Title: Re: Core Repair Under Cowl Vents
Post by: glennd3 on July 11, 2019, 01:54:37 PM
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".
Title: Re: Core Repair Under Cowl Vents
Post by: KWKloeber on July 11, 2019, 03:33:29 PM
IIWMB I’d want to determine how much if any is rotted. How do you answer the question w/o knowing that?
Title: Re: Core Repair Under Cowl Vents
Post by: Noah on July 11, 2019, 04:48:28 PM
Ok Ken, first tell me/us what the heck “IIWMB” means...?
Title: Re: Core Repair Under Cowl Vents
Post by: KWKloeber on July 11, 2019, 05:02:39 PM
OH C’MON.  I learned that frum Stu.
Title: Re: Core Repair Under Cowl Vents
Post by: Noah on July 11, 2019, 05:04:58 PM
And????
Title: Re: Core Repair Under Cowl Vents
Post by: mdidomenico on July 11, 2019, 05:37:23 PM
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.
Title: Re: Core Repair Under Cowl Vents
Post by: Noah on July 11, 2019, 06:24:19 PM
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. 
Title: Re: Core Repair Under Cowl Vents
Post by: Jon W on July 11, 2019, 06:40:05 PM
IIWMB - If It Were My Boat
Title: Re: Core Repair Under Cowl Vents
Post by: KWKloeber on July 11, 2019, 07:36:50 PM
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

Title: Re: Core Repair Under Cowl Vents
Post by: Noah on July 11, 2019, 07:50:40 PM
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.
Title: Re: Core Repair Under Cowl Vents
Post by: Jon W on July 11, 2019, 08:20:19 PM
I give, what’s YBM2I stand for.
Title: Re: Core Repair Under Cowl Vents
Post by: KWKloeber on July 11, 2019, 08:52:52 PM
U beat me 2 it  8)
Title: Re: Core Repair Under Cowl Vents
Post by: Robert Mann on July 12, 2019, 10:34:16 AM
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.
Title: Re: Core Repair Under Cowl Vents
Post by: KWKloeber on July 12, 2019, 10:53:49 AM
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.   
Title: Re: Core Repair Under Cowl Vents
Post by: Noah on July 12, 2019, 11:32:34 AM
The solar vent covering is not relative. I believe drilling straight down the cowl vent mounting screw holes won’t reach far enough laterally to determine/fix any creeping core damage, as the vent pedestal is a hollow box that is several inches above the deck level. If water got into the core it has perhaps migrated. You will have to explore and excavate for damage from below sideways where the tube meets the deck crack and if it is soft laterally you will have to drill from outside, further back outside border of the vent tower pedestal or from below—or cut an inspection hole into the pedestal box and repair pedestal afterwards. Not fun.
Title: Re: Core Repair Under Cowl Vents
Post by: KWKloeber on July 12, 2019, 08:24:46 PM
Re: Noah’s

Ah yes, I just now was able to look at pics.  I took MB comment that they weren’t on a dorade, that they were mounted directly on a flat deck. Obviously a bad ass/u/me. 

Ok, that mea culpa said, what is the construction of the riser?  Are they solid?  Hollow and “sit” on a solid deck? Other?

Mike, what dia are the rings?  Is there enuf space to get vents on there?

Title: Re: Core Repair Under Cowl Vents
Post by: Noah on July 12, 2019, 09:13:30 PM
The towers for the “dorade boxes/pedestal towers” (whatever you want to call them) I believe are hollow with a 3in. or 4 in. diameter fiberglass tube inserted in the middle that penetrates/intersects through the deck into cabin headliner. Getting to what is inside the deck that is surrounding the tubes, under those hollow towers, is where I see the possible issue. His photos are pretty self explanatory. Unless I am mistaken on how the towers are constructed. 
Title: Re: Core Repair Under Cowl Vents
Post by: KWKloeber on July 13, 2019, 09:46:23 AM
The towers for the “dorade boxes/pedestal towers” (whatever you want to call them) I believe are hollow with a 3in. or 4 in. diameter fiberglass tube inserted in the middle that penetrates/intersects through the deck into cabin headliner. Getting to what is inside the deck that is surrounding the tubes, under those hollow towers, is where I see the possible issue. His photos are pretty self explanatory. Unless I am mistaken on how the towers are constructed.

Thanks Noah for the come back on that (which was indeed a question not a statement or an opinion, because it ended in ?s, not with periods.)
I’m trying to picture in my mind how they are formed - the c30 mk-II has similar towers (not the mk-I and dropped on the mk-III, not sure about the II-1/2) and tho I’ve looked for it there’s no good info about our’s construction (I’d have to think they share similarities?)  AFAIK (= as far as I know) cost had always driven Frank/Gerry designs so I’m thinking the least cost way. Obviously the shell/shape is formed (upside down) in the deck mold and the guts laid up (or down as it were) and the easiest/quickest is probably how it was done (time is most costly, difference in material is nil.)  That would lead me to believe (I guess this constitutes pontificating?) that the traveler and adjacent cowl mount were “continuously” filled en masse (easy?) around a tube. Obviously that’s just speculation. Our forum has a very knowledgeable guy on general construction - worked for 2-3 mfgrs (= manufacturers) but not specifically CTY (= Catalina.)  It’s not really germane to mr brown’s problem but thanks anyway.

Oh PS, yep the pix (= digital photographs) are telling once I viewed them - I dint realize mike posted them as they don’t show on the forum text-only version (which is easier to use on my phone screen.)
Title: Re: Core Repair Under Cowl Vents
Post by: Stu Jackson on July 13, 2019, 05:56:53 PM
I've got the same condition on my port vent.  Finally traced it down to, most likely (we think, Les Troyer the C36 tech editor and I), the wood around the sliding hatch. 

I'm currently praying for no rain, even though we desperately need some!!!  :cry4` :cry4` :cry4`

Here's a very good discussion about that wood trim:

http://c34.org/bbs/index.php/topic,7191.0.html
Title: Re: Core Repair Under Cowl Vents
Post by: Noah on July 13, 2019, 06:20:27 PM
Stu- Somewhat different issue I believe. I think Mike’s concern was to determine how much the crack in the vent tube at deck level has damaged the core (has it migrated under the cowl tower?)—and how to fix it? But haven’t heard a response from Mike, so I may be all wet here? 8)
Title: Re: Core Repair Under Cowl Vents
Post by: Stu Jackson on July 13, 2019, 11:14:50 PM
Noah, good points, I should have been more clear.  In my case, there was water dripping through those cracks in the "tube."  That's why we had to trace it down to some source.  I rebedded the cowl.  No luck.  I rebedded the traveler track.  No luck.  It's simply a process of elimination t identify what's UP THERE...:D

If there are only cracks and no water, it's purely cosmetic, and all I'd do is slather MarineTex on it and call it a day.  In my case, I needed to find the source of the water ingress to avoid the water's egress through those cracks.  (I should be so lucky...:D)
Title: Re: Core Repair Under Cowl Vents
Post by: rmbrown on July 15, 2019, 08:36:25 AM
I opted to cut out the top of the tower, expose the rotten wood... hopefully all of it... by removing as much fiberglass skin as I could and still have the patch covered by the 9" vent.

I used a zip saw to follow my pencil line and I've managed to get down 1/2 to 3/4 inches... and I'm still in fiberglass!  These towers don't appear to be hollow and don't appear to entirely wood filled.  I've emailed Warren Pandy at Catalina for more intel.  I just sealed it back up this weekend and decided to sleep on it.

Here's a photo of where I'm cutting.
Title: Re: Core Repair Under Cowl Vents
Post by: KWKloeber on July 15, 2019, 11:23:27 AM
Hey Mike

Here’s another thought that it’s likely someone will comment doesn’t apply to C-34s, or isn’t germane to, or is pontificating about your unfortunate tower situation  :cry4`
When we check out the condition of the (sometimes just wet, sometimes rotted) wooden plank buried in the c30 keel stub, we drill down thru the bilge w/a 1/4” bit, into the wood and extract/inspect the chips (dry - wet - rotted.) You could do the same because you’re already “committed” to covering/fixing the surface.

IIWMT (if it were my tower) I’d start with the screw holes, progressing in a pattern depending on what you find each time. You might find the lay up is competent in all but a few spots that could be treated by using infusing penetrating resin.  At least you might define ahead of time what spot(s) need to be gouged-out if it’s more widespread.  Of course, it would also define whether the box is vacant below some depth or fully occupied.

Is what you’ve found so far matching with this approach?

If that approach makes sense, lastly depending of course on the findings/extent, I’d drill a series of holes outside the tube circumference and inject penetrating resin to make sure that crack leakage is fixed. Could be in conjunction with Dremeling out the crack(s) and injecting resin from inside the tube (attacking the attack from two directions as it were.) 

IIWMT (no need to repeat) I’d drill it incrementally — based on “chip feedback” drilling to the core level incrementally to determine both the extent and depth (if any) of the rot layer.  You may find (makes sense) that it’s all laying down at the “deck level.”

How tall is the tower (realizing of course, that I’m opening the door for continuing personal attacks because I should have bought a 34 so I don’t need to clog up the forum with such silly questions about it’s construction.)  Can you reach to the crack level with a jobber bit or would you need an electrician’s bit?  Whatever length, I’d mark it with BRIGHT 8) tape so you reach to the core level and hopefully not thru the headliner. :shock: )

Gee I wonder what the negative feedback will be this time?


Title: Re: Core Repair Under Cowl Vents
Post by: rmbrown on July 15, 2019, 11:36:06 AM
In hindsight, it being 2020, or even better, I wish I'd just drilled through the screw holes to see what I have... but I'm pretty sure (not) that what I'll find is a small ring of plywood glassed into the tower that's likely  got some rot but could be sufficient repaired by just overdrilling and filling with epoxy, and then way more significant core damage at deck level. 

I'd guess the tower is 3" tall, from hull liner to deck plate mounting surface and I'd further guess that about 2" of that is tower and 1" is deck.

If have my thoughts on what the inside of the tower looks like but I'm really hoping that Warren @ Catalina will educate me before I proceed. :)
Title: Re: Core Repair Under Cowl Vents
Post by: KWKloeber on July 15, 2019, 12:02:27 PM
Mike I agree with, close to 100% of your assessment. It may be polyester resin/ply or resin/matting but doesn’t really matter since both are hydrophilic. Structurally I doubt (99.9%) there’s any issues but I know you want it repaired. I would be surprised if the rot is very extensive - the crack just caused by our (infrequent) freeze cycles over here.  I think it’s just needing to arrest any more intrusion and infusing what’s easy and sleep better.
You might also try GD directly. ( Gerard@ )

I believe there’s many construction “shop drawings” that are not in the (30 or 34) documentation (I’ve seen a few.)  Sure wish we could get hands on a complete set, but maybe they also were lost in the flood.
Title: Re: Core Repair Under Cowl Vents
Post by: rmbrown on July 15, 2019, 12:07:46 PM
I'll give warren a day or so and then call. :)
Title: Re: Core Repair Under Cowl Vents
Post by: rmbrown on July 15, 2019, 02:45:10 PM
Warren's reply...

***********

Hi Mike,
Below the teak ring, the “raised tower” should be all fiberglass and FRP related products, so the wood deck core typically won’t be found or start until you are about 3/8” to ½” below the surface of the surrounding walk deck.
WP

***********

It looks like all I did from the top was make a mess... I'll either have to cut all the way down, which would be crazy, cut up from the bottom, or tackle it from inside the tube.   Time to sleep on it.
Title: Re: Core Repair Under Cowl Vents
Post by: Noah on July 15, 2019, 03:40:06 PM
Mike-Very sorry if I steered you wrong on the towers being hollow. I said I wasn’t sure, but probably little comfort. However if Warren is correct, then Stu’s comments were important, as perhaps the cracking at the deck inside the tubes was not from your dorade vent cowl at all—as the screws securing those to the tower  went into solid glass—not exposed core. Thus your leak, if you have one, is coming from elsewhere, and showing up in the tube/deck joint. I would just dig from the side in the cracks and see how far you get. And/or drill a few small holes and see what come out in the shavings.
Title: Re: Core Repair Under Cowl Vents
Post by: rmbrown on July 15, 2019, 03:53:34 PM
Noah... rest easy my friend... no placing blame here.  I cut into that tower primarily because the screws that hold the deck plates and teak trim rings down only go 1/2" into that deck tower and, since two of them spun out, I assumed that "wood" was rotten!

Also, while I can definitely see the possibility of the water getting to the core some other way, I'm hopeful that's not the case because while on a 2+ week trip, we had a lot of rain and both cowls had water dripping from the core... bad enough that I had dishpans under them.  I removed both cowls and screwed in the deck plates and wet them with a hose... the dripping, from the core split, was immediate.  I pulled up the trim rings and deck plates with the intention of rebedding them with butyl tape.  I got one rebedded but only two screws would hold and, since there was a storm coming, I just taped a piece of plastic over the screw holes and deck plate 3.75" opening.  Two days of rain and no drip.  Sprayed it with a hose and no drip.  Not one single drop from either cowl vent, then or since.  Question then is how is the water getting from the upper screw holes to the core... I think me and a 1/2" bit are going to answer that question from the top.  Unless, of course, I change my mind before I get back to the boat saturday. :D
Title: Re: Core Repair Under Cowl Vents
Post by: Stu Jackson on July 15, 2019, 06:02:43 PM
Mike, I, too, rebedded my cowl as the "obvious" first step.  Thought the leak was stopped because the water stopped dripping.  That first rebed was at the Roche Harbor Catalina Rendezvous in May 2017.  Les Troyer and John Shepard were great helpers.  In fact, they were so enthusiastic that I watched them gather the tools (long "blade" on John's power drill, Les working out the butyl tape I'd supplied), that they had the work done before I could ask them to stop and let me even try to help! :clap

The leak, which manifested itself by drips through one of the three screws holding the trim ring in (I removed the ring and saw a smaller version of your cracks), stopped for awhile, only to reappear (when it started raining again).  I tried that again; definition of insanity, right?

Then I did the traveler track.  Stopped, but then it rained, showed up later in the winter and early spring.

I saw Les again in early April this year, demanding my money back as part of the warranty!!!!!! :cry4` :cry4` :cry4`  We both laughed.

He and I traced it down to the fairleads for some of my aft led lines that run back to the cockpit (two small bullet fairleads, small screws, but could be).

The only other thing above that hole inside up on the deck is the hatch wood trim.

It's been dry here for months, no drips.  I can readily believe your results with the hose, but my experience was it took longer to reappear.

I was tempted to just slather Marine Tex inside and stop the drips, but, like you, I want to find the source and stop that.

That's where the link I posted could come in handy.

With my luck, I'll get around to doing that work only once it starts raining again!  Just like when I rebedded my saloon hatch!

Good luck, please keep us posted.
Title: Re: Core Repair Under Cowl Vents
Post by: derekb on July 15, 2019, 07:57:38 PM
Mike, I'm also watching with interest. I have drips coming from the vent above my galley, so I may be in for the same fix.

Regards,
Derek
Title: Re: Core Repair Under Cowl Vents
Post by: lazybone on July 16, 2019, 12:02:45 PM
Could it be the Mainsheet traveler attachment points.  They are slightly uphill and sort of close by.
Title: Re: Core Repair Under Cowl Vents
Post by: GYPSEA on July 24, 2019, 09:25:42 AM
I too had this issue..... I chipped away at it all. Then took an allen wrench on a drill and got back into the hole as far as possible or until I didn't see any more wet wood. When i reached in on particular large section, I found a wad of duct tape - there was a bit of a gap!
From the gap - I was able to get to dry wood all the way round except out toward the side of the boat. I drilled a couple holes about 5 inches away from the dorade hole toward the side of the boat just enough to verify the wood shavings were dry.....
Then I glassed it up and painted it white.
Title: Re: Core Repair Under Cowl Vents
Post by: Noah on July 24, 2019, 09:33:23 AM
Gypsea- Did you determine what was leaking/what was causing your wet deck?
Title: Re: Core Repair Under Cowl Vents
Post by: rmbrown on July 24, 2019, 12:01:24 PM
Could you determine the brand of duct tape?  I'll likely need to replace mine.

 :shock:
Title: Re: Core Repair Under Cowl Vents
Post by: Noah on July 24, 2019, 12:12:37 PM
BTW Mike- have you seen these replacement dorade “kits” at CD?

https://www.catalinadirect.com/shop-by-boat/catalina-42/hull-deck/midship/cowl-vent-dorade-box-plastic-w-ss-mushroom-vent-c-34-c-36-c-42/
Title: Re: Core Repair Under Cowl Vents
Post by: rmbrown on July 24, 2019, 12:58:45 PM
Noah:

I have, and I considered them, but I ended up getting the solar day/night vents instead.  I might regret that decision.  I'll let you know!

Mike