Conductive lubrication for sliding anode on to shaft

TwoHooter

TwoHooter

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Our boat has a "prop nut" anode which fits snugly over the nut which secures the propeller and a short length of the shaft.
This particular anode is always a tight fit but the one I have in my hand now really does not want to go on.
I think that a little bit of lubricant would help.
Any ideas for conductive lubricants that won't affect the continuity between anode and shaft? I don't want to put a barrier on the shaft and rely only on the securing bolt for continuity.
Thanks.
20210928_162112.jpg
 
Try a bit of soap & water, that might work. Grease is not conductive, and any creases with metallic properties (molyslip, copperslip etc) are just introducing another metal into the mix.

My thoughts are to use something that will wash away easily, even hairspray (don't laugh - we used to use that for fitting MTB grips back in the day).
 
I'd look at it the other way, as if you wanted to isolate the two items; in this scenario it'd be practically impossible. In my ROV experience I've never encountered this as a problem and believe that you'll not be able find a lack of continuity between the two.
 
TwoHooter said:
Our boat has a "prop nut" anode which fits snugly over the nut which secures the propeller and a short length of the shaft.
This particular anode is always a tight fit but the one I have in my hand now really does not want to go on.
I think that a little bit of lubricant would help.
Any ideas for conductive lubricants that won't affect the continuity between anode and shaft? I don't want to put a barrier on the shaft and rely only on the securing bolt for continuity.
Thanks.
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I would use grease, if that is going to help you fit it, then fit the securing bolt and check the continuity between anode and shaft/prop with a multimeter, which I always do anyway for peace of mind. If less than 1 ohm resistance than all is good.

Www.solocoastalsailing.co.uk
 
Thanks all.
Yes I always check for continuity, every lift-out, right round the boat, every bit of metal, not just the anodes.
Heat is an obvious solution but I have to line up 3 grub screws which stop it turning, which might be difficult if it's hot. Also I wonder about getting it off when it needs to be changed. I suppose heat again.

EDIT it's so tight I doubt I need the grub screws!
 
What's wrong with using a file to make it a slightly less tight fit? That way you'll also be able to get the remnants off again
 
bedouin said:
I seem to remember from my schooldays that vaseline is a very good conductor.
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I just stuck my test meter probes into a pot of Vaseline. No conductivity. I get conductivity if the probes are touching while in the Vaseline but I don't know if the test current is passing through the stuff or the bare metal is making contact.
Ammonite said:
What's wrong with using a file to make it a slightly less tight fit? That way you'll also be able to get the remnants off again
Click to expand...
I assume you mean file the anode, not the shaft :) . The anode is not a collar like an ordinary shaft anode, it's a solid dome shape. There's nowhere to run a file through. I could put it in the lathe and skim a smidgin off but the lathe is 3 hours' drive away, we're a one car household, and the car is at home with my wife. 12 hours' driving for a job like this in the middle of a fuel crisis sounds a bit mad. If I had a small flap wheel I could use that, but I've only got one wheel on the boat and it's too big. I hate being without a car. I've got a Dremel but I'll never get an even abrasion round the circumference with that. I think it's going to have to be either heat or a drop of washing up liquid in some water. (I haven't got any hairspray).
 
You can get a small flap wheel or a drum sanding attachment for the dremel fairly easily and cheaply from most DIY stores. If it is only a slight interference fit then one of these will do the trick for you. If they won't take enough out, then the fit is too tight for grease to make the difference.
 
Can’t get in with some emery paper? Even a drill bit on an electric drill should be able to shave the sides, it’s quite soft metal
 
TwoHooter said:
Our boat has a "prop nut" anode which fits snugly over the nut which secures the propeller and a short length of the shaft.
This particular anode is always a tight fit but the one I have in my hand now really does not want to go on.
I think that a little bit of lubricant would help.
Any ideas for conductive lubricants that won't affect the continuity between anode and shaft? I don't want to put a barrier on the shaft and rely only on the securing bolt for continuity.
Thanks.
View attachment 123249
Click to expand...
Electrically conductive grease is sold under that description In Aus I bought from Jaycar this month approx $14 per tube. Try electrical wholesalers.
 
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