Reply
 
Thread Tools Search this Thread Display Modes
 
Old 10-05-2014, 10:27 AM   #1
Veteran Member
 
City: bayonne
Join Date: Oct 2014
Posts: 65
Cool Keel Fairing

does anybody know if i't worth the work to fair the aft end of a mainship 1 keel?
richardschmidt2759 is offline   Reply With Quote
Old 10-05-2014, 10:54 AM   #2
Guru
 
Nomad Willy's Avatar
 
City: Concrete Washington State
Vessel Name: Willy
Vessel Model: Willard Nomad 30'
Join Date: Oct 2007
Posts: 18,743
Pics and boat speed?
__________________
Eric

North Western Washington State USA
Nomad Willy is offline   Reply With Quote
Old 10-05-2014, 01:58 PM   #3
Guru
 
Scary's Avatar
 
City: Walnut Grove Ca
Vessel Name: Cary'D Away
Vessel Model: Hatteras 48 LRC
Join Date: Apr 2012
Posts: 887
Probably not

I's not a racing boat, I doubt if you will reduce any drag. It could improve bottom shots however, for the forum.
Scary is offline   Reply With Quote
Old 10-05-2014, 03:18 PM   #4
Valued Technical Contributor
 
DavidM's Avatar
 
City: Litchfield, Ct
Join Date: Aug 2012
Posts: 6,785
Fairing may not do any good. I faired the deadwood behind the keel on my Mainship Pilot 34. I couldn't tell any difference. And by Mainship I I presume you mean the original 34 sedan. That is at best a 12kt boat with the Perkins 165, so I wouldn't expect much improvement there either.

Here are before and after pics of my keel:
Attached Thumbnails
Bella my pic faired deadwood 1 small.jpg  
Attached Images
 
DavidM is online now   Reply With Quote
Old 10-05-2014, 04:22 PM   #5
Guru
 
Mule's Avatar
 
City: Fort Pierce
Vessel Name: Florita Ann
Vessel Model: 1982 Present
Join Date: May 2014
Posts: 1,935
Go to the Mainship yahoo forum, there are extensive conversations. In the archives there are pix and how to. One guy claims he picked up 300 rpm as memory serves. More impt to me is upsizing the too far forward, undersized rudder. Mine is sold to be funded this week.
Mule is offline   Reply With Quote
Old 10-05-2014, 08:21 PM   #6
Guru
 
C lectric's Avatar
 
City: Gibsons, B.C., Canada
Vessel Name: Island Pride
Vessel Model: Palmer 32'
Join Date: Oct 2007
Posts: 4,414
I don't know about your boat but I've seen a couple done including one Seabird 37' sailboat owned by a fellow I know.
It was not to pick up any speed. It was to reduce noise. The trailing edge of the keel was blunt and close and the eddies and swirls, when they hit the prop, caused a lot of noise.

He was a shipwright and had experience with doing other boats for much the same reason.
He told me it made a noticeable difference. I cannot verify it because I didn't hear the before and after.

On a powerboat , even a slow one, it might help noise reduction. Just a question of how much and is it worthwhile. That I cannot answer.
C lectric is offline   Reply With Quote
Old 10-05-2014, 10:58 PM   #7
Guru
 
Nomad Willy's Avatar
 
City: Concrete Washington State
Vessel Name: Willy
Vessel Model: Willard Nomad 30'
Join Date: Oct 2007
Posts: 18,743
C lectric,
Not putting your comments down one bit but we have a 6 knot Willard and she has a very squared off keel termination and don't have a vibration problem at all.

One or two Willard owners have done the mod but I have no knowledge about improvement or not. I thought about it but my concerns about efficiency were in another life. Not enough time either. You could probably spend your time or money better elsewhere.

But I may be wrong.
__________________
Eric

North Western Washington State USA
Nomad Willy is offline   Reply With Quote
Old 10-06-2014, 07:21 AM   #8
Guru
 
jleonard's Avatar
 
Join Date: Jun 2008
Posts: 5,037
Fairing the keel is without doubt worth the effort. I did tha job on my ex Mainship 1. Just from that alone I gained 250 rpm at WOT and you can do the math what that means thru the entire rpm range. I was able to add 2 inches of pitch and still spin up to proper rpm and then some.
It is a very simple project that takes maybe 6 or 8 hours worth of labor. I made my fairing bullet shaped.

Mule, that was me and I thought the rudder was fine but I guess that's a matter of opinion.

By the way you can witness and perhaps prove to yourself as I did how the fairing will help. I did this one driveway at home during a rainstorm. While the water was running downhill I took a 2x10 and used it to dam up the water just the the flat end keel on the Mainship. I was amazed how much the water was displaced as it went around the board. It really upset the water flow. I was convinced a fairing would help.
__________________
Jay Leonard
Ex boats: 1983 40 Albin trunk cabin, 1978 Mainship 34 Model 1
New Port Richey, Fl
jleonard is offline   Reply With Quote
Old 10-06-2014, 09:39 AM   #9
Guru
 
Mule's Avatar
 
City: Fort Pierce
Vessel Name: Florita Ann
Vessel Model: 1982 Present
Join Date: May 2014
Posts: 1,935
Quote:
Originally Posted by jleonard View Post
Fairing the keel is without doubt worth the effort. I did tha job on my ex Mainship 1. Just from that alone I gained 250 rpm at WOT and you can do the math what that means thru the entire rpm range. I was able to add 2 inches of pitch and still spin up to proper rpm and then some.
It is a very simple project that takes maybe 6 or 8 hours worth of labor. I made my fairing bullet shaped.

Mule, that was me and I thought the rudder was fine but I guess that's a matter of opinion.

By the way you can witness and perhaps prove to yourself as I did how the fairing will help. I did this one driveway at home during a rainstorm. While the water was running downhill I took a 2x10 and used it to dam up the water just the the flat end keel on the Mainship. I was amazed how much the water was displaced as it went around the board. It really upset the water flow. I was convinced a fairing would help.
Ok, I was looking at doing your mod next time out, but she sold first. The rudder issue came to a head when I had a 5 knot ebb in the Fort Pierce inlet take the boat away from me twice. I was giving her all she had, 9.5 knots, normal 14.5, and lost her 2x. Had to hard to hard to get her pointed. I was ready the second time, still could not stop her. That is when I determined, along with the following sea issue the rudder was not right.

After that underwear tearing incident I determined it might be wise to keep ebb and flow in mind when shooting the inlet. Lesson learned. I went from 250 hp Cummins @ 7 ton to 135hp@ 13 ton so tidal movement will be a priority hence forth.
Mule is offline   Reply With Quote
Old 10-06-2014, 10:15 AM   #10
Veteran Member
 
City: bayonne
Join Date: Oct 2014
Posts: 65
Thanks guys! great response to a new guy! glad I joined this group! I will most likely do this job while up for winter. I live in jersey so cold weather will be here soon, need a new project! THANKS,AGAIN RICH S . P.S I will let you know how it worked out in the spring.
richardschmidt2759 is offline   Reply With Quote
Old 10-06-2014, 02:49 PM   #11
Guru
 
jleonard's Avatar
 
Join Date: Jun 2008
Posts: 5,037
This is a picture of what I did the only one I can find. I made the base blocks from 2 pieces of pressure treated 4x4, epoxied them to the hull, then faired them with a disk grinder, then 3 layers of 1 1/2 ounce mat and polyester resin, gelcoat when finished.
Attached Thumbnails
fairing.jpg  
__________________
Jay Leonard
Ex boats: 1983 40 Albin trunk cabin, 1978 Mainship 34 Model 1
New Port Richey, Fl
jleonard is offline   Reply With Quote
Old 10-06-2014, 04:39 PM   #12
Guru
 
Mule's Avatar
 
City: Fort Pierce
Vessel Name: Florita Ann
Vessel Model: 1982 Present
Join Date: May 2014
Posts: 1,935
Just to be clear.....before pix....
Mule is offline   Reply With Quote
Old 10-07-2014, 05:56 AM   #13
Guru
 
jleonard's Avatar
 
Join Date: Jun 2008
Posts: 5,037
Quote:
Originally Posted by Mule View Post
Just to be clear.....before pix....
I don't have a before pic but the keel was flat as it is where the stern tube bolts on. All I did was ADD the fairing blocks above and below the stern tube.
__________________
Jay Leonard
Ex boats: 1983 40 Albin trunk cabin, 1978 Mainship 34 Model 1
New Port Richey, Fl
jleonard is offline   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

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


» Trawler Port Captains
Port Captains are TF volunteers who can serve as local guides or assist with local arrangements and information. Search below to locate Port Captains near your destination. To learn more about this program read here: TF Port Captain Program





All times are GMT -5. The time now is 03:29 PM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2006 - 2012