Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 21-04-2008, 13:51   #1
Senior Cruiser

Cruisers Forum Supporter

Join Date: Dec 2004
Location: Royal Oak, Michigan, USA
Boat: 1977 Cuttyhunk 59 Ketch, "Diva" in Trinidad
Posts: 175
Images: 276
Send a message via Yahoo to Geoff S.
AC discharge thru-hull: below waterline, or piss off my neighbours?

My Quandry of the Week:

After peeling, reglassing and refairing, my hull is a complete blank canvas, and I'm free to put new thru-hulls for everything wherever they seem to make the most sense. We're installing ac units (one under the forward cabin bunk, and one aft in the lazarette), and I'm faced with the choice of putting their raw water discharge thru-hulls below the waterline with all its associated sink-the-boat issues...or about 12" above the waterline, which causes the boat to sound like it has a bladder infection all night; could be an auditory nuisance to my neighbours at anchor. Of course, when I'm using them at night, they'll be running off the generator, and while the gennie lives in the engine room and as such the running noise shouldn't be much of an issue for my fellow cruisers, it will have it's own discharge...so maybe the cooling discharge is a moot point?

What are any pros and cons of the two configs that come to mind?

Thankee,
Geoff
__________________

__________________
"Give a man a fish, and he can eat for a day. Give a man a boat, and he can't afford to eat for the rest of his life."
Geoff S. is offline   Reply With Quote
Old 21-04-2008, 14:56   #2
Provocateur & Raconteur
 
knottybuoyz's Avatar

Cruisers Forum Supporter

Join Date: Nov 2005
Location: Iroquois, Ontario
Boat: Bateau.com TW31 Modified
Posts: 3,583
Images: 87
Hey Geoff

Thought you had already sailed off into the sunset! Got more pics of the boat project?

Can't you locate the AC discharges closer to the waterline? I've seen them just above or in the bootstripe and that lowers the angle the stream hits the water. Seems to be a lot quieter that way. Anti-siphon loops would fix any problems with sinking the boat via the AC discharge eh?

Rick
__________________

__________________
Yours Aye! Rick
~^~^~^^~^~^~^~^~^~^~^~~^~^~~^~^~^^~~^~^
"It's not the boat "you built" until you've sworn at it, bled on it, sweated over it, cried beside it and then threatened to haul the POS outside and burn it!"
knottybuoyz is offline   Reply With Quote
Old 21-04-2008, 15:16   #3
Senior Cruiser

Cruisers Forum Supporter

Join Date: Jul 2006
Location: Chesapeake Region and Maine
Boat: 42' Bob Perry sloop
Posts: 4,038
Images: 4
I agree with Rick. I put mine just above the bootstripe and, in addition to the loop, I installed shutoff ball valves (belt and suspenders logic!). Works great, and doesn't make a lot of noise.

Bill
__________________
btrayfors is offline   Reply With Quote
Old 21-04-2008, 15:32   #4
Registered User
 
Latitude9.5's Avatar

Join Date: Jun 2006
Boat: CAL 3-46
Posts: 441
Send a message via AIM to Latitude9.5
I thought about my install for quite a while, what I did was above the waterline, but it's at a part in the hull where it's angled directly at the water, it's makes hardly any noise at all. At our marina there are a lot of them that make a lot of noise, everyone just lives with it, i honestly can't hear even the loudest ones inside the boat.
__________________
Latitude9.5 is offline   Reply With Quote
Old 21-04-2008, 15:38   #5
CF Adviser
Moderator Emeritus
 
Hud3's Avatar

Cruisers Forum Supporter

Join Date: Sep 2007
Location: Virginia
Boat: Island Packet 380, now sold
Posts: 8,929
Images: 49
Geoff,

Just make sure you install the water intake thru-hulls on the opposite side of the keel from the head discharge!!! And opposite the A/C discharges, too, to prevent recirculation.

Course you probably already thought of that!
__________________
Hud
Hud3 is offline   Reply With Quote
Old 21-04-2008, 17:04   #6
Registered User

Join Date: Nov 2005
Location: New Orleans
Boat: Nomoboat -- yay Gustav ;)
Posts: 248
Send a message via AIM to drew.ward
What about using the same simple technique used to quell noise on building downspouts?

Simply attach a piece of rope to the inside of the pipe at some point and let that run out your through hull and down to the waterline.

Because water is hydrophilic to itself, it will cling to the rope and silently flow down into the water. This way you can have your through-hulls as high as you like.
__________________
drew.ward is offline   Reply With Quote
Old 21-04-2008, 17:09   #7
Registered User
 
Latitude9.5's Avatar

Join Date: Jun 2006
Boat: CAL 3-46
Posts: 441
Send a message via AIM to Latitude9.5
Mine comes out with a vengence, not a trickle.
__________________
Latitude9.5 is offline   Reply With Quote
Old 21-04-2008, 18:06   #8
Senior Cruiser

Cruisers Forum Supporter

Join Date: Dec 2004
Location: Royal Oak, Michigan, USA
Boat: 1977 Cuttyhunk 59 Ketch, "Diva" in Trinidad
Posts: 175
Images: 276
Send a message via Yahoo to Geoff S.
Good thoughts, all. I was thinking that, even at the proposed 12" above the waterline, it would still be underwater when heeling, so the above-water safety argument is kind of moot. Bootstripe seems like a good place.

Come to think of it, every time I'm in a "quiet" anchorage, I can't hear the water discharges over the wind generators!
__________________
"Give a man a fish, and he can eat for a day. Give a man a boat, and he can't afford to eat for the rest of his life."
Geoff S. is offline   Reply With Quote
Old 21-04-2008, 18:41   #9
Marine Service Provider
 
AnchorageGuy's Avatar

Join Date: Mar 2003
Location: Wherever the boat is!
Boat: Marine Trader 34DC
Posts: 4,618
Forget at anchor, we have seen marinas with floating docks make the owners turn off the AC units because they hosed the docks down when the discharge is up high.
__________________
Chesapeake Bay, ICW Hampton Roads To Key West, The Gulf Coast, The Bahamas

The Trawler Beach House
Voyages Of Sea Trek
AnchorageGuy is offline   Reply With Quote
Old 22-04-2008, 01:06   #10
Senior Cruiser
 
Alan Wheeler's Avatar

Cruisers Forum Supporter

Join Date: Dec 2003
Location: Marlborough Sounds. New Zealand
Boat: Hartley Tahitian 45ft. Leisure Lady
Posts: 8,038
Images: 102
I doubt the other residents would be all that concerned. I would think you and the others on board would be more concerned with the water noise. And then, there is nothing like the gentle sound of running water to put you to sleep.
__________________
Wheels

For God so loved the world..........He didn't send a committee.
Alan Wheeler is offline   Reply With Quote
Old 22-04-2008, 03:04   #11
Registered User

Join Date: Nov 2006
Posts: 976
Images: 6
....and nothing like the continuous drone of a small engine running a generator all night to keep you awake.....
__________________
cooper is offline   Reply With Quote
Old 22-04-2008, 04:17   #12
Registered User

Join Date: Apr 2006
Posts: 4,413
How about this for an odd suggestion: get some elbows fabricate that you can slip into the thru hull from the outside when you are at anchor which conduct the water to below the water line? I know this would look weird and require you set this up at anchor, but it would suppress any noise WHEN you want to. This might even work with hose that you can shove into the thru hull. You can make it work!
__________________
Sandero is offline   Reply With Quote
Old 22-04-2008, 06:22   #13
Registered User

Join Date: Nov 2005
Location: Ohio
Posts: 2,313
I would be concerned about siphoning. Besides, with all the in mast furlers howling all night long who would hear the trickle of water?
__________________
Joli is offline   Reply With Quote
Old 23-04-2008, 03:39   #14
Registered User

Join Date: Nov 2006
Posts: 976
Images: 6
Click image for larger version

Name:	Boat05-10-01.JPG
Views:	132
Size:	31.8 KB
ID:	3394


Somthing like this !!! (a small pin hole at the elbo stops siphoning) This one unscrews with a course thread "milk pipe ring"
__________________
cooper is offline   Reply With Quote
Old 23-04-2008, 08:24   #15
Senior Cruiser

Cruisers Forum Supporter

Join Date: Dec 2004
Location: Royal Oak, Michigan, USA
Boat: 1977 Cuttyhunk 59 Ketch, "Diva" in Trinidad
Posts: 175
Images: 276
Send a message via Yahoo to Geoff S.
Then, if you could rotate them to blast drunks on dinghies at 2am...
__________________

__________________
"Give a man a fish, and he can eat for a day. Give a man a boat, and he can't afford to eat for the rest of his life."
Geoff S. is offline   Reply With Quote
Reply

Tags
thru hull

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Admiral 40 Balsa Below Waterline laser Construction, Maintenance & Refit 28 08-06-2010 17:01
Waterline vs Raw-Water Strainer sildene Engines and Propulsion Systems 28 17-02-2010 20:39
No Discharge Zones engcon Liveaboard's Forum 3 10-01-2007 01:51
Head discharge lines clogged with marine growth? ssullivan Plumbing Systems and Fixtures 27 23-10-2006 10:04
Percy Island TV cover piss poor Bob Norson Cruising News & Events 2 11-06-2006 13:39



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 21:59.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.