Split pin advice

[pault1]

Can anyone advise on which type of split pin to use to hold my prop on.

Stainless shaft, bronze prop.

The one I used last season has corroded away.



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[dickh]

Stainless Steel is usually used - it should not corrode away. Was it stainless or zinc plated steel? Zinc plated steel would corrode very quickly. Use an anode on the prop shaft as well.

<hr width=100% size=1>dickh
I'd rather be sailing... /forums/images/icons/smile.gif

 

[DeeGee]

With galvanic corrosion there are three important things to remember above all others. First is that the material which is higher up the galvanic scale (go Googling to find one of the umpteen out there) gets minimal corrosion, the lower gets serious corrosion. Second, the bigger the difference in the galvanic potential (position in that table), the more the corrosion. Third, the anode (ie the lower in the table) corrosion is inversely proportional to its area - i.e. a big area spreads the corrosion thin.

Now, your particular case. If you stick a s/s pin in a s/s shaft then it will just add to the s/s elements, and not suffer significant corrosion, unless it is a type of s/s lower down the scale from your prop s/s material. With a bit of luck they will both be 316 or A4, and it will be the bronze which gets de-zinc'd. Of course, if you have a nice big anode, then it will be the anode which gets corroded and your nice prop, shaft and split pin will all be nicely clean under the barnacles when you haul out next time.


<hr width=100% size=1>Black Sugar - the sweetest of all

 

[vyv_cox]

Nice answer.

One other thing, touched upon in DeeGee's reply. There is stainless and then there is stainless. It may well be possible to buy split pins in a 400 series steel, it is certainly possible to buy many other fastenings in it. 400 series steels are not great in seawater. Best way for you to test is with a magnet. 300 series are not attracted, 400 series are.

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[30boat]

If you can't find proper 316 stainless split pins you can always use 316 Tig welding rods.These are stamped so no doubts there.They come several thicknesses.

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