Propeller shaft wiper shoe replacement

The friendliest place on the web for anyone who enjoys boating.
If you have answers, please help by responding to the unanswered posts.
See posts with no answers
adornato

adornato

Senior Member
Joined
Oct 10, 2007
Messages
121
Location
USA
Vessel Name
Sarah McLean
Vessel Make
Mainship 30 Pilot
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/products/propeller-shaft-wipers-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.
 
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.
 
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
 
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.
 
I use a brush with brass bristles. Brush lightly rubs the shaft and wire is soldered to the bristles.
 
Mine actually has a motor brush soldered to the arm.
 
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.
 
Our boat has the Electra-Gard system that relies on the shaft wipers. I keep them and the shafts clean with commutator paper.
 
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.
 
Mischief Managed said:
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.
Click to expand...


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/jaw-type-couplings/


Jim
 
Circumnavigator said:
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/jaw-type-couplings/


Jim
Click to expand...


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.
 
Circumnavigator said:
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/jaw-type-couplings/


Jim
Click to expand...
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.
 
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
 
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/bonding-systems-and-corrosion-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.
 
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?
 
SteveK said:
Steve, I read the linked article twice and cannot find a conclusion to the mismatched wear on hull anodes.
Click to expand...

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.
 
Last edited:
C lectric said:
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?
Click to expand...

ScotchBrite is perfect for this application.
 
Thanks Steve. You are the go to guy for this stuff. I guess I can put my Oilite bearing that I crafted to replace the missing carbon brush on the Pro Mariner wand in the scrap metal heap.
I do have two aluminum collar electrodes on the prop shaft already.
 
Yeah I'm afraid so, and Oilite bearing stock is probably worse for the application because the impregnated oil is an insulator.

If you have anodes on the shaft you are covered.
 
You must log in or register to reply here.

Similar threads

S
Propeller Shaft Zinc Reality Check
Replies
8
Views
569
Snapdragon III
Snapdragon III
J
Aluminum/Zinc Anodes
Replies
20
Views
2K
fstbttms
fstbttms
M
Prop shaft too short for ZINC
Replies
21
Views
2K
AKDoug
AKDoug
S
Replacing Shaft Coupler Bolts?
Replies
11
Views
934
boomerang
boomerang
man7sell
Replacement steering wheel
Replies
18
Views
1K
man7sell
man7sell

Latest posts

Back
Top Bottom