harrytom 653 Posted October 26, 2018 Share Posted October 26, 2018 Any current from enginecould travel down shaft.seal has water in it which will be touch bronze fitting.zinc on shaft wears away. Can just be a simple case of salt crystals drying on fitting.amazing how salt gets in from air even though no physical water. Yet to see any bronze fittings on a vessel that has not tarnished over the years and has no white on it. Salt water is amazing stuff and when dry how/where it makes contact. Quote Link to post Share on other sites
harrytom 653 Posted October 26, 2018 Share Posted October 26, 2018 My first yacht was surveyed and the second / tap fitting never got picked up as a problem.bronze skin fitting with a ss tap with a copper tail. Engine water intake corroded and butterfly thing inside gave way and copper tail fell off due to corrosion.vessel sank on mooring.insurabce sent parts away for analysing. Result due to combination if dissimilar caused failure Quote Link to post Share on other sites
Crazyhorse 47 Posted October 26, 2018 Author Share Posted October 26, 2018 Yep, that would happen as the components are all in contact with each other. The trouble for us is the fizzing gland is not touching anything but the kauri shaft log. The PSS is rubber mounted, cutlass is vesconite so non conductive. It will be interesting next year when we pull the lot out! Post a few pics too. I'm sure Noel is right that the wood has seawater leaching in around where the gland is and is reacting creating caustic soda? Quote Link to post Share on other sites
Island Time 1,252 Posted October 26, 2018 Share Posted October 26, 2018 Again, fastener corrosion. Common in wooden boats. All you need is damp wood - which is conductive. It’s in the link I posted above. 1 Quote Link to post Share on other sites
Crazyhorse 47 Posted October 27, 2018 Author Share Posted October 27, 2018 Again, fastener corrosion. Common in wooden boats. All you need is damp wood - which is conductive. It’s in the link I posted above. Links involve mostly electrical conduction (potential). This is a chemical reaction that probably isn't helped by stray currents but bonding etc isn't going to achieve anything. The sodium chloride, bronze, oxygen and high sap content of kauri timber creating NaOH. Looks like lots of vinegar squirting coming up. I have removed that non connected big zinc from the shaft log, a nice big gap now needing filling, as its of no use anyway. Another old coger in the yard here Matt said its a common problem, he had the same and lasted years on a kauri boat. Use white vinegar, period. Only problem now is having a penchant for fish'n'chips all the time Now!! Quote Link to post Share on other sites
Island Time 1,252 Posted October 27, 2018 Share Posted October 27, 2018 Fastener corrosion isn’t electrical, as in the article above. The fact that damp timber conducts, and can be part of a “circuit”, is not necessarily relevant in this case. Quote Link to post Share on other sites
Crazyhorse 47 Posted February 8, 2019 Author Share Posted February 8, 2019 Latest up date. The gland is no longer fizzing, stopped squirting it with white vinegar some time ago . Now it's slowing oozing a brown thick liquid! Seems to seeping out from the timber around it. What's going on!!? Quote Link to post Share on other sites
waikiore 410 Posted February 10, 2019 Share Posted February 10, 2019 Old spilt Rum slowly coming out in this hot weather? Quote Link to post Share on other sites
Crazyhorse 47 Posted February 10, 2019 Author Share Posted February 10, 2019 Old spilt Rum slowly coming out in this hot weather? Haha..tends to gather further forward of the engine but like your thinking!! Quote Link to post Share on other sites
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