Rudder Stock

[Guest]

ZEEPRET is a Pioneer 9 aged 42. I have just removed the ruddeer for examination and am puzzled by the material. There is a little pitting but otherwise no corrosion. It is highly magnetic and appears crystalline - because of the small amount of corrosion I would appreciate any comments on what material could have been used - the alternatives appear to be cast or forged steel.

I would also be interested to hear from any other owners of these remarkable boats.

 

[brianhumber]

From your desription could well be classic electrolytic action. When I was at sea in MN saw many pump shafts, valve stems bolts etc with pitting. It varies in severity depending on the type of electrosis and where the 'battery cell' develops on the surface of the material.
If yours is 42 with just little pitting seems your shaft is good.
Can very bad, I have known pump shafts that are 'hollow' and the shaft is turning as normal in the pump gland but the shaft in way of the impellor has disappeared. Was on a ship once that tried to cure this by making EVERY nut and bolt connection electrically isolated by means of fibre washers etc. Doing all this was not popular with the ER staff and did not work anyway.