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10-19-2022, 06:19 PM
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#1
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Senior Member
City: San Francisco
Vessel Name: Sarah McLean
Vessel Model: Mainship 30 Pilot
Join Date: Oct 2007
Posts: 121
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Propeller shaft wiper shoe replacement
I have a galvanic corrosion preventer shaft wiper on my Mainship 30. it has a 1.5inch shaft. i also have a aluminum collar anode which disappears more frequently than i like (but we have done the whole marina check, galvanic isolator etc etc).
the carbon shoe on the wiper has worn away or fallen out and i want a new shoe.
I see some bronze looking shoe online :
https://store.sandiegomarine.com/pro...ers-15339.html
BUT i find it hard to cough up $54.00 for a shoe. any ideas on another source of a shoe replace conductive shoe on the shaft. the wiper arm looks fine.
and I know some of you will just say forget about it and put two $!5 "zincs" collars on the shaft.
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10-20-2022, 07:12 AM
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#2
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Guru
City: Olympia
Vessel Name: Rendezvous
Vessel Model: Blue water 40
Join Date: Aug 2021
Posts: 1,815
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That shoe is just a piece of oilite bronze bushing cut in half and fitted with a mounting stud. If you don’t want to pay 50 bucks, just make it yourself.
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10-20-2022, 04:34 PM
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#3
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Senior Member
City: San Francisco
Vessel Name: Sarah McLean
Vessel Model: Mainship 30 Pilot
Join Date: Oct 2007
Posts: 121
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thanks. very helpful . i was wondering what the shoe was made of. now i just have to find a short length of oilite bearing that is a little more than the 1 1/2 shaft diameter
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10-21-2022, 08:19 PM
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#4
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Guru
City: Gibsons, B.C., Canada
Vessel Name: Island Pride
Vessel Model: Palmer 32'
Join Date: Oct 2007
Posts: 4,414
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Take a look at most of the 1/2 pipe shaft wipers.
THe actual contact is somewhat smaller than the shaft diameter so the wiper rides on top and the edges contact the shaft for better wiping, cleaning the contact area and better electrical contact.
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10-21-2022, 11:39 PM
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#5
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Guru
City: Between Oregon and Alaska
Vessel Name: Charlie Harper
Vessel Model: Wheeler Shipyard 83'
Join Date: Jun 2016
Posts: 3,023
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I use a brush with brass bristles. Brush lightly rubs the shaft and wire is soldered to the bristles.
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10-22-2022, 07:13 PM
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#6
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Guru
City: Gibsons, B.C., Canada
Vessel Name: Island Pride
Vessel Model: Palmer 32'
Join Date: Oct 2007
Posts: 4,414
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Mine actually has a motor brush soldered to the arm.
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10-22-2022, 07:24 PM
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#7
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Guru
City: Groton, CT
Vessel Name: Datenight
Vessel Model: North Pacific 45
Join Date: Jan 2008
Posts: 1,106
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Quote:
Originally Posted by C lectric
Mine actually has a motor brush soldered to the arm.
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Mine as wel.
Rob
__________________
North Pacific 45
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10-23-2022, 08:56 AM
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#8
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Guru
City: Hampton Beach, NH
Vessel Name: Mischief Managed II
Vessel Model: 1992 Tollycraft 44 CPMY
Join Date: Oct 2018
Posts: 675
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I'm not convinced those shaft wipers do much, at least on my boat. I tested the boat without them this season and the shaft anode wear was proportional to the anode wear elsewhere on the boat, just like last year. If you have a rubber coupler between the transmission and the shaft I suppose they would be a good idea, I don't have a rubber coupler.
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10-23-2022, 09:01 AM
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#9
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Senior Member
City: Lake Oswego, Oregon
Vessel Name: Stout
Vessel Model: Nordic Tug 42
Join Date: Dec 2013
Posts: 189
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Saw this strap shown on the SENTOA forum:
https://static1.squarespace.com/stat...Strap+indd.pdf
Another option anyway.
__________________
Cheers, Kevin
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10-23-2022, 11:09 AM
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#10
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Guru
Join Date: Dec 2007
Posts: 4,021
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Our boat has the Electra-Gard system that relies on the shaft wipers. I keep them and the shafts clean with commutator paper.
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10-23-2022, 11:23 AM
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#11
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Guru
City: Ft Pierce
Vessel Name: Sold
Vessel Model: Was an Albin/PSN 40
Join Date: Oct 2011
Posts: 28,151
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i made mine using the shaft zincs I took off las haul out. The zinc is soft and conductive.
May not be the best, but the price was right as well as good conductivity.
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10-23-2022, 04:38 PM
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#12
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Senior Member
City: West Newbury.
Vessel Name: none
Join Date: Oct 2020
Posts: 422
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Quote:
Originally Posted by Mischief Managed
I'm not convinced those shaft wipers do much, at least on my boat. I tested the boat without them this season and the shaft anode wear was proportional to the anode wear elsewhere on the boat, just like last year. If you have a rubber coupler between the transmission and the shaft I suppose they would be a good idea, I don't have a rubber coupler.
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Agreed -- I guess I don't understand why anyone needs a wiper. If the shaft is solidly mounted to the gear, then it's grounded. If there's a Lovejoy* coupling there, then a piece of #8 wire from one side to the other will ground the shaft far more solidly than a wiper.
Or am I missing something?
* https://www.lovejoy-inc.com/products...ype-couplings/
Jim
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10-24-2022, 07:50 PM
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#13
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Guru
City: Gibsons, B.C., Canada
Vessel Name: Island Pride
Vessel Model: Palmer 32'
Join Date: Oct 2007
Posts: 4,414
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Quote:
Originally Posted by Circumnavigator
Agreed -- I guess I don't understand why anyone needs a wiper. If the shaft is solidly mounted to the gear, then it's grounded. If there's a Lovejoy* coupling there, then a piece of #8 wire from one side to the other will ground the shaft far more solidly than a wiper.
Or am I missing something?
* https://www.lovejoy-inc.com/products...ype-couplings/
Jim
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It may or may not be. THis has been discussed many times by some expert people. The internal parts are often isolated by the oil once the gear is not running. In fact even while running the oil film that separates the metal parts may insulate enough to compromise any grounding effect.
To me it is not worth the chance. The zincs and/or brush are far cheaper than a new prop or shaft.
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10-24-2022, 08:17 PM
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#14
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Guru
City: Gulf Islands, BC Canada
Vessel Name: Sea Sanctuary
Vessel Model: Bayliner 4588
Join Date: Jul 2019
Posts: 5,017
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Quote:
Originally Posted by Circumnavigator
Agreed -- I guess I don't understand why anyone needs a wiper. If the shaft is solidly mounted to the gear, then it's grounded. If there's a Lovejoy* coupling there, then a piece of #8 wire from one side to the other will ground the shaft far more solidly than a wiper.
Or am I missing something?
* https://www.lovejoy-inc.com/products...ype-couplings/
Jim
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I am guessing eventually most will know I have my own opinion on bonding.
Why have a wiper when the engine block is already bonded?
IMO, you are correct, shaft zincs are already protecting the shaft and prop. But like many other redundant things why not have a wiper that can be visually inspected and which create a circuit from the zinc to shaft/prop and back to zinc. Many times a bonding wire is found broken, but since you are not supposed to daisy chain, wire in series, only one item is out of the circuit back to zinc.
So to depend on the electrical flow to go through multiple bolted connections, any of which may have failed to avoid a brushed shaft is not sound policy. That is if you want it all bonded.
__________________
SteveK
You only need one working engine. That is why I have two.
Sea Sanctuary-new to me 1992 Bayliner 4588
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10-25-2022, 10:39 AM
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#15
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Senior Member
City: San Francisco
Vessel Name: Sarah McLean
Vessel Model: Mainship 30 Pilot
Join Date: Oct 2007
Posts: 121
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I bought a smaller than the shaft oilite bushing from McMaster Carr for 5 bucks. Am drilling and splitting it in half to mount on the wiper arm as a replacement for the carbon shoe that fell off and disappeared or disappeared and fell off. I also have a aluminum collar anode on the shaft.
belt and suspenders
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10-28-2022, 04:52 PM
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#16
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Guru
City: Deltaville
Join Date: Dec 2015
Posts: 1,069
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Unless the shaft brush uses silver slip rings, it doesn't work, none of the carbon or bronze half pipe versions meet the 1 ohm or less cathodic protection requirement. If you are intent on protecting the shaft an drop with a hull anode, you'd need to invest in the slip ring version. See https://stevedmarineconsulting.com/b...on-prevention/ and https://www.boatcorrosion.com/product-slip-rings.html for additional details.
The transmission is anything but a sub one ohm medium, the oiled gears and bearings will provide high resistance at best, if any continuity at all.
If you shaft has room for an anode (or two), it's really not necessary.
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10-28-2022, 05:35 PM
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#17
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Guru
City: Gulf Islands, BC Canada
Vessel Name: Sea Sanctuary
Vessel Model: Bayliner 4588
Join Date: Jul 2019
Posts: 5,017
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Quote:
SDA, Hold that thought, I'll return to that story later.
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Steve, I read the linked article twice and cannot find a conclusion to the mismatched wear on hull anodes.
__________________
SteveK
You only need one working engine. That is why I have two.
Sea Sanctuary-new to me 1992 Bayliner 4588
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10-28-2022, 06:43 PM
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#18
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Guru
City: Gibsons, B.C., Canada
Vessel Name: Island Pride
Vessel Model: Palmer 32'
Join Date: Oct 2007
Posts: 4,414
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Hopefully Steve sees and replies to your point.
If there are two anodes supposedly sharing the protection job and one is eaten away with the other barely touched then the barely touched one is not connected or at least the connection has degraded severely and it not doing anything.
I've had this on my own boat. I have a large steel keel and maintain 6 anodes, 3 per side, on it. One year one of the anodes was barely touched.
I had someone else install them the previous haulout. I checked with my meter and as I suspected, the continuity was POOR so the anode was just along for the ride.
I replaced the other 5 and cleaned the daylights out of the mounting faces, keel and anode, especially on the failing one.
Next haulout all 6 were eaten about equally.
I talked to the guy and he just thought it was a good anode. I showed him the use of the ohm meter as a check for continuity. I think he got it but I never asked him to replace my anodes again.
I was using hand wire brushes and on my drill but at Steve's caution some while ago I now use just sandpaper or similar. Just as long as the mounting surfaces are bright and clean. Scotchbrite also?
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10-29-2022, 11:58 AM
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#19
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Guru
City: Deltaville
Join Date: Dec 2015
Posts: 1,069
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Quote:
Originally Posted by SteveK
Steve, I read the linked article twice and cannot find a conclusion to the mismatched wear on hull anodes.
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My apologies, I will fix that, somehow that part got left our when it was posted to the site.
The answer is, the near pristine anode's bonding wire was loose, which increased the resistance, which rendered that anode ineffective.
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10-29-2022, 11:58 AM
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#20
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Guru
City: Deltaville
Join Date: Dec 2015
Posts: 1,069
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Quote:
Originally Posted by C lectric
Hopefully Steve sees and replies to your point.
If there are two anodes supposedly sharing the protection job and one is eaten away with the other barely touched then the barely touched one is not connected or at least the connection has degraded severely and it not doing anything.
I've had this on my own boat. I have a large steel keel and maintain 6 anodes, 3 per side, on it. One year one of the anodes was barely touched.
I had someone else install them the previous haulout. I checked with my meter and as I suspected, the continuity was POOR so the anode was just along for the ride.
I replaced the other 5 and cleaned the daylights out of the mounting faces, keel and anode, especially on the failing one.
Next haulout all 6 were eaten about equally.
I talked to the guy and he just thought it was a good anode. I showed him the use of the ohm meter as a check for continuity. I think he got it but I never asked him to replace my anodes again.
I was using hand wire brushes and on my drill but at Steve's caution some while ago I now use just sandpaper or similar. Just as long as the mounting surfaces are bright and clean. Scotchbrite also?
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ScotchBrite is perfect for this application.
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