Catalina 34

General Activities => Main Message Board => Topic started by: anaisdog on July 17, 2014, 07:15:19 AM

Title: replacing VETUS cowl vents
Post by: anaisdog on July 17, 2014, 07:15:19 AM
Hello all - first post here.  I have a 1986 34 (hull 99) and it has the 4 inch (Tom model) VETUS cowl vents on it.  I read the article here, about replacing them and my first question is why do they all freeze (as listed in the article)?  Secondly, should I replace with the same model or is there a better idea, for a vent?  I already replaced the Nicro vent fans with the solar version, in the head and in the aft cabin so I have air moving around.

thank you.  lots more questions

becki kain
detroit, mi
Title: Re: replacing VETUS cowl vents
Post by: Les Luzar on July 17, 2014, 08:59:51 AM
Mine were never frozen, but they were really weathered and discolored. So I replaced them with new cowl vents from Vetus. I chose the "Tom" model. Another C-34 that I know, installed the stainless steel ones. Some others have removed them all together. It is simply your preference. I myself, have not seen any other alternatives. It is however, your personal choice.
Title: Re: replacing VETUS cowl vents
Post by: anaisdog on July 17, 2014, 10:09:03 AM
Did you replace the dorado box and the cowl?  Is the actual mechanism part of the box or part of the cowl or sold separately?  There seem to be no instructions, on line, even from VETUS, about their installation and since the PO had installed the solar fans upsidedown, it would not surprise me if my cowl vents are just installed wrong as well.  thank you
Title: Re: replacing VETUS cowl vents
Post by: Stu Jackson on July 17, 2014, 10:35:30 AM
August 2005 Tech Notes has an article on dorade/cowl replacement
Title: Re: replacing VETUS cowl vents
Post by: Les Luzar on July 17, 2014, 11:03:37 AM
I just replaced my cowl's, which are simply wind scoops and simple to replace. All of the mechanisms are inside the dorade box. 
Title: Re: replacing VETUS cowl vents
Post by: sailaway on July 17, 2014, 03:02:35 PM
Becki I replaced my old vetus  cowls with new vetus cowls . With in 3 yrs they where discolored an look terrible.  They were the white plastic ones Charlie
Title: Re: replacing VETUS cowl vents
Post by: lazybone on July 17, 2014, 03:31:28 PM
Paint em.
Title: Re: replacing VETUS cowl vents
Post by: Stu Jackson on July 17, 2014, 04:04:02 PM
Cleaning?  "Paint Brush & Cleaner" from ACE Hardware.  Also great for fenders, better and easier than acetone.
Title: Re: replacing VETUS cowl vents
Post by: anaisdog on July 18, 2014, 05:56:24 AM
I will get that, thank you.  It was in that article where I read "they all freeze" so I was wondering why they froze but I'll just replace them once I get all the leaks fixed.  thanks
Title: Re: replacing VETUS cowl vents
Post by: pjcomeau on July 18, 2014, 07:13:31 AM

If your happy with your dorade and cowl vents, then you can just replace the "mushroom vents" (allot cheaper). Mine were all corroded and were not opening/closing properly. I replaced mine (the dorade/cowl were in good enough shape).

The trick was to match up the Vetus parts (TOM is used for Cowl and Dorade, but for some reason use Athos for the mushroom alone). All you do is match cutout openings from the TOM Darade to the Athos mushroom vent.

http://www.defender.com/product3.jsp?path=-1|6880|2290139|2290143&id=1634207 (http://www.defender.com/product3.jsp?path=-1%7C6880%7C2290139%7C2290143&id=1634207)
http://www.defender.com/product.jsp?path=-1|6880|2290139|2290147&id=1646962 (http://www.defender.com/product.jsp?path=-1%7C6880%7C2290139%7C2290147&id=1646962)
Title: Re: replacing VETUS cowl vents
Post by: anaisdog on July 19, 2014, 06:34:45 AM
THANKS!  I wasn't even certain what to call these things so I wasn't certain what to look up.  yes both the cowl and the dorado box are fine, just dirty.  so based on this:
https://www.flickr.com/photos/10826951@N04/14688343764/
https://www.flickr.com/photos/10826951@N04/14710608743/in/photostream/
it looks like i have the 6inch one and i can just replace the inner mushroom not the whole thing.  I still can't figure out how this thing actually stays open but I'll install and see.  what did you use to bed it?  I know butyl is big in some circles.  thanks
Title: Re: replacing VETUS cowl vents
Post by: Stu Jackson on July 19, 2014, 10:35:43 AM
Becky, the tech note I referenced discusses that the best way to keep the old internal metal parts, and to service them, is from the top, not below.  Take the whole shegang off and you will see what's there.  There are also pictures in that article.
Title: Re: replacing VETUS cowl vents
Post by: anaisdog on July 19, 2014, 02:05:07 PM
thanks Stu, there is no servicing these puppies.  for unknown reasons, the screw is all bashed up, on both, so the thing won't stay up.  BUT i'd much rather spend 65 each, for new innards that 220 each, for the whole thing!
Title: Re: replacing VETUS cowl vents
Post by: Ken Juul on July 19, 2014, 08:13:39 PM
I can think of very few reasons why you would want the dorades closed. In a decade plus of ownership the only time I've closed mine was when I bug bombed the boat.   Air movement is good.  If the horns are in good shape, just remove the insides and enjoy.
Title: Re: replacing VETUS cowl vents
Post by: lazybone on July 20, 2014, 01:40:45 PM
I close them when the AC is running.
Title: Re: replacing VETUS cowl vents
Post by: Ken Juul on July 20, 2014, 08:12:39 PM
Touche!

Hadn't thought about doing that. Next time it gets unbearablly hot here I'll  try that to see if it makes a difference.  Usually when it get that hot, no air is blowing anyway.  But I'll give it a try.
Title: Re: replacing VETUS cowl vents
Post by: pjcomeau on July 22, 2014, 10:36:16 AM
Becki,

I can't remember what I used to re-bed (I know it was not butyl, since I had not discovered this great option until more recently). It's a pretty simple mechanism, the mushroom/cover is attached to a threaded post. On the other end is a knob that you turn one way and screws open (wider), and the other to close (or less wide).

Like you mine were unusable and even the screen was falling apart. Not sure what previous owner had done to get then so rusted.

Good luck.
Title: Re: replacing VETUS cowl vents
Post by: anaisdog on August 01, 2014, 01:19:39 PM
How do you install the ATHOS?  does the white trim ring go inside the boat (I assume) and the metal trim goes on top?  what did you use to bed it on both sides?  I'm still very confused as to how this thing works
Title: Re: replacing VETUS cowl vents
Post by: anaisdog on August 01, 2014, 01:24:17 PM
Stu, or anyone else, what would you bed this vent with, in the cabin and on top?  butyl?  silicone?  4200?  something else?  you just list sealant, in the article  thanks

Title: Re: replacing VETUS cowl vents
Post by: Ron Hill on August 01, 2014, 02:22:16 PM
Becki : I'd use clear or white silicone to bed them after you install the new "innards".  You are bedding screws that are going into fiberglass, so any squeeze out will match the gelcoat. 

I posted a Mainsheet tech note tip - that I tightened the inside nut so the vent would stay in open position.  Then I installed a 4" Beckson port on the inside of the cabin over the Vetus trim ring (the holes line up - need a longer screw), so if I wanted to close the port I screwed in the Beckson cap and didn't have to fool around with Vetus mechanism!!

Many a time I "closed" those ports in the winter or spring when it was cold and I was staying on the boat!!  I had both a "tent safe" catalytic propane and a small electric heater.

A few thoughts
Title: Re: replacing VETUS cowl vents
Post by: anaisdog on August 01, 2014, 02:27:02 PM
thanks.  so the white trim ring goes on the inside of the boat (with silicone), the metal goes inside that, from the top, with silicone?  i just don't want to screw this up!
Title: Re: replacing VETUS cowl vents
Post by: Ron Hill on August 01, 2014, 03:07:51 PM
Becki : The white/clear silicone I was talking about is around each screw on the OUTSIDE of the two pieces of the 4" Vetus dorade.  One piece holds the dorade to the molded piece on the deck and the other piece is a ring that holds the TOM "horn" on that other piece. 

There is a trim ring on the inside overhead just so it looks nice - no need for any caulk on it!

Clear as mud??
Title: Re: replacing VETUS cowl vents
Post by: anaisdog on August 01, 2014, 03:08:31 PM
the metal one needs no caulk?
Title: Re: replacing VETUS cowl vents
Post by: anaisdog on August 01, 2014, 03:10:06 PM
and good gravy, would it have killed vetus to send installation instructions????

Title: Re: replacing VETUS cowl vents
Post by: Stu Jackson on August 02, 2014, 07:33:07 PM
Quote from: anaisdog on August 01, 2014, 01:24:17 PM
Stu, or anyone else, what would you bed this vent with, in the cabin and on top?  butyl?  silicone?  4200?  something else?  you just list sealant, in the article  thanks



I used silicone when I did that article, but would use butyl now.



Title: Re: replacing VETUS cowl vents
Post by: anaisdog on August 03, 2014, 07:09:26 AM
k, good.   i just ordered my first (two) rolls of butyl last night.  do you just put it around the screws and then the outside of the vent?
Title: Re: replacing VETUS cowl vents
Post by: Stu Jackson on August 03, 2014, 08:55:13 AM
Quote from: anaisdog on August 03, 2014, 07:09:26 AM
k, good.   i just ordered my first (two) rolls of butyl last night.  do you just put it around the screws and then the outside of the vent?

Yes, assume you're familiar with Maine Sail's website tutorial on how to "Bed It With Butyl."
Title: Re: replacing VETUS cowl vents
Post by: anaisdog on August 03, 2014, 08:58:46 AM
no but i'll find it. thanks!
Title: Re: replacing VETUS cowl vents
Post by: Stu Jackson on August 03, 2014, 09:02:41 AM
Here it is:

http://www.pbase.com/mainecruising/rebedding_hardware (http://www.pbase.com/mainecruising/rebedding_hardware)
Title: Re: replacing VETUS cowl vents
Post by: mregan on August 06, 2014, 06:51:47 AM
I used butyl on everything.  I had to replace one of the mushroom caps this spring.  I used butyl on that then used butyl on the dorade base to deck connection and butyl on the dorade to the base connection.
Title: Re: replacing VETUS cowl vents
Post by: Indian Falls on August 18, 2014, 02:56:11 PM
Try reading this thread on replacing the Dorades and cowl with air only ventilators.

http://c34.org/bbs/index.php/topic,6238.msg41189.html#msg41189