|
|
10-03-2011, 19:12
|
#1
|
Registered User
Join Date: Dec 2010
Posts: 5
|
Grounding Shaft with a DriverSaver
Does anyone know how to maintain the continuity between the engine and shaft with a driversaver installed? I have heard of grounding brushes or jumper straps but have not found details on installation. Thanks
|
|
|
10-03-2011, 19:17
|
#2
|
Registered User
Join Date: Dec 2008
Location: St. Georges, Bda
Boat: Rhodes Reliant 41ft
Posts: 4,131
|
Re: Grounding shaft with a drivervsaver
Shaft brushes are usually an "off the shelf" item for chandlers. Basically a 12" long x 1" wide flat bar which attaches to a mounting point on the hull, adjacent to the prop shaft. A heavy carbon brush, mounted on the flat bar, contacts the shaft for continuity, and connects into your bonding system.
__________________
so many projects--so little time !!
|
|
|
11-03-2011, 20:05
|
#3
|
Registered User
Join Date: Dec 2010
Posts: 5
|
I guess it was a matter of knowing the right name. I found lots of references to shaft brushes, rather than grounding brush. Thanks for clarifying. Sailnh
|
|
|
12-03-2011, 04:08
|
#4
|
Registered User
Join Date: Dec 2008
Location: St. Georges, Bda
Boat: Rhodes Reliant 41ft
Posts: 4,131
|
Re: Grounding Shaft with a DriverSaver
Made by Guest # 2436, out of Meriden CT.
__________________
so many projects--so little time !!
|
|
|
12-03-2011, 04:37
|
#5
|
Registered User
Join Date: Oct 2010
Location: Avalon, NJ
Boat: Albin 40 double cabin Trawler
Posts: 1,886
|
Re: Grounding Shaft with a DriverSaver
Quote:
Originally Posted by Sailnh
Does anyone know how to maintain the continuity between the engine and shaft with a driversaver installed? I have heard of grounding brushes or jumper straps but have not found details on installation. Thanks
|
use standard grounding wire with crimped eyes..also have seen flat braid used...anything that gives a zero ohm reading should work for bonding...jumping up to lightening protection would be a challenge as that's one system that's hard to say when "big" is big enough...
|
|
|
12-03-2011, 04:54
|
#6
|
Moderator
Join Date: Aug 2009
Location: Solent, England
Boat: Moody 31
Posts: 18,423
|
Re: Grounding Shaft with a DriverSaver
This is a uk supplier but they probably don't maufacturer it so someone else does. As already suggested, the local chandler should be able to source one for you.
Product Catalogue - Marine Cathodic Protection - MGDUFF
|
|
|
12-03-2011, 06:32
|
#7
|
Registered User
Join Date: Jun 2007
Location: Tarpon Springs, FL
Boat: Pearson 303 30' Grateful Sailor
Posts: 32
|
Re: Grounding Shaft with a DriverSaver
You are correct in wanting a ground around the DriverSaver. Years ago a Practical Sailor reader wrote in recommending the benefits of having a DriveSaver. He also added this thought "the slight galvanic action between the prop and shaft will discourage marine growth. Ha! the joke was on me. Several years later when I pulled the boat for a new bottom the yard informed me that I needed a new prop. This five year old bronze prop was pitted and had turned pink.
Along with a new prop, I added strips of copper foil between the steel shaft couplings and haven't had any more issues.
Ken
|
|
|
17-03-2011, 13:00
|
#8
|
Registered User
Join Date: Dec 2009
Location: Cruising Eastern Caribbean
Boat: Taswell 49
Posts: 1,199
|
Re: Grounding Shaft with a DriverSaver
If the prop has its own zinc (maxprop) and there is a collar zinc on the shaft what is the benefit or reason for creating continuity between the engine and an the prop/shaft?
|
|
|
17-03-2011, 14:11
|
#9
|
Registered User
Join Date: May 2006
Location: Nyack, NY
Boat: Westsail 32
Posts: 1,690
|
Re: Grounding Shaft with a DriverSaver
Quote:
Originally Posted by SV Escape Plan
If the prop has its own zinc (maxprop) and there is a collar zinc on the shaft what is the benefit or reason for creating continuity between the engine and an the prop/shaft?
|
Some boats ground to the engine. I am installing the R&D shaft saver as part of my refiit, they will supply as an option a little strap to maintain continuity. Hope this helps.
|
|
|
19-03-2011, 02:11
|
#10
|
Registered User
Join Date: Jun 2007
Location: Tarpon Springs, FL
Boat: Pearson 303 30' Grateful Sailor
Posts: 32
|
Re: Grounding Shaft with a DriverSaver
It seems reasonable that the zinc should be enough protection. In my experience it wasn't.
I work for a company that builds lifting equipment for large yachts. One of our produces in a s/s transom platform lift use to raise and lower a jetski or tender into the water. Even though this lift is supplied with a zinc we recommend that lift be bonded to the vessel's bonding system. A major boat builder chose not to do this. Consequently, the lift suffered serious galvanic corrosion. The damage was not covered under warranty.
|
|
|
19-03-2011, 05:05
|
#11
|
Registered User
Join Date: Oct 2010
Location: Avalon, NJ
Boat: Albin 40 double cabin Trawler
Posts: 1,886
|
Re: Grounding Shaft with a DriverSaver
Quote:
Originally Posted by SV Escape Plan
If the prop has its own zinc (maxprop) and there is a collar zinc on the shaft what is the benefit or reason for creating continuity between the engine and an the prop/shaft?
|
Even though underwater metals can be somewhat protected by zinc, a proper bonding system will eliminate any electrical potential between objects...which I believe is the root cause of the galvanic action.
|
|
|
20-03-2011, 18:35
|
#12
|
Registered User
Join Date: Feb 2009
Location: A real life Zombie from FL
Boat: Gulfstar 53 - Osiris
Posts: 5,416
|
Re: Grounding Shaft with a DriverSaver
I have had a Drivesaver for near-on 15 years and love the things. But to reconnect the engine to the prop shaft I merely ran a short piece of braided copper strap (from an auto parts store) from one bolt on one side to another bolt on the other side. Simple and has worked fine for over 10 years so far.
|
|
|
21-03-2011, 11:31
|
#13
|
Registered User
Join Date: Dec 2009
Location: Cruising Eastern Caribbean
Boat: Taswell 49
Posts: 1,199
|
Re: Grounding Shaft with a DriverSaver
Ok well I guess I will add a wire here and connect the shaft and prop to my DC ground but I have yet to see a really good reason. I do not have a bonding system on my boat and will not add one. All of my through hulls are marelon. I dont understand why these items would need to be connected to the engine block (DC ground) if they have their own anodes? I dont leave my boat plugged in to shorepower except to top off batteries then it gets unplugged. What am I missing here? What does this connection do for me?
|
|
|
21-03-2011, 13:12
|
#14
|
Registered User
Join Date: May 2009
Location: Massachusetts
Boat: 40' Silverton Aftcabin with twin Crusaders
Posts: 1,791
|
Re: Grounding Shaft with a DriverSaver
I made my own shaft brushes. I used a piece of brass bar stock silver soldered to a brass hinge. First I tried soldering a piece of bronze on the end of the brass bar stock allowing it to ride on top of the prop shaft. The ground was made to via a length of #12 wire between the bar stock and the boat's ground.
Surprise, surprise! The bronze that rode on the shaft wore so badly after about an hours run, I had to change the design. Version 2...... I replaced the bronze with a pipe like piece of oilite bearing material. I removed quite a bit of material from the center of the the bearing which was about 1" in diameter almost 2" in length. Cutting out the center reduced the amount of weight on the shaft. Used my lathe to cut the center material. Each of my two shafts have these assemblies.
The assembly applies about !/4# pressure on the shaft. Absolutely no visible wear using oilite.
Foggy
|
|
|
21-03-2011, 13:34
|
#15
|
Registered User
Join Date: Dec 2009
Location: Cruising Eastern Caribbean
Boat: Taswell 49
Posts: 1,199
|
Re: Grounding Shaft with a DriverSaver
Quote:
Originally Posted by foggysail
I made my own shaft brushes. I used a piece of brass bar stock silver soldered to a brass hinge. First I tried soldering a piece of bronze on the end of the brass bar stock allowing it to ride on top of the prop shaft. The ground was made to via a length of #12 wire between the bar stock and the boat's ground.
Surprise, surprise! The bronze that rode on the shaft wore so badly after about an hours run, I had to change the design. Version 2...... I replaced the bronze with a pipe like piece of oilite bearing material. I removed quite a bit of material from the center of the the bearing which was about 1" in diameter almost 2" in length. Cutting out the center reduced the amount of weight on the shaft. Used my lathe to cut the center material. Each of my two shafts have these assemblies.
The assembly applies about !/4# pressure on the shaft. Absolutely no visible wear using oilite.
Foggy
|
Sounds pretty neaat and all but Why? Im still wondering what all of this actually accomplishes?
|
|
|
|
|
Thread Tools |
Search this Thread |
|
|
Display Modes |
Rate This Thread |
Linear Mode
|
|
Posting Rules
|
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts
HTML code is Off
|
|
|
|
Advertise Here
Recent Discussions |
|
|
|
|
|
|
|
|
|
|
|
|
Vendor Spotlight |
|
|
|
|