Prop zinc sleeves/screws

[MV Dana Louise]

Hello Fellow CatCruisers -

I just returned from relaunching MV Dana Louise at Harbortwon Marine in Fort Pierce [unscathed from two hurricane eyes less a new Bimini].

Here, however are a few tips on prop[ zincs. We previously lost one underway and investigation showed that the machince screws originally installed were so short that there were only a few threads 'engaged'.
When I ordered new zincs from West Marine I also ordered one bronze sleeve to have a spare. When I compared the new sleeve to the originals I found about twice as many interior threads available in the bronze to accept the prop zinc screws as on the originals.

Net, 1] check for lost zincs and 2] when you are hauled I suggest checking betweeen the bronzes and the screws to see just what you have. The conservative move is to have a spare 'full set' of bronze sleeve and new zincs and to make sure the machine screws are fully threading. I would add some 5200 for good measure. Be carefull however to not overtighten - ss into bronze and you know what will break!

I hope this saves at least one owner from a lost zinc - spinning off.

Brian

[Gadzooks!]

Brian:

When Gadzooks reached Vancouver on the freighter (my first opportunity to see the hulls out of the water), I found both prop zincs had gone missing somewhere between Whitby and Port Everglades. Both sleeves were still there - I'm assuming that the little cage-like thingamajig the zinc attaches to is the "sleeve".

Sounds like Whitby should give some attention to this.

[MV Dana Louise]

Hello, After a long absence but still enjoying our MV greatly. By now I assume most everyone has done the 'reverse machine screw fix' to stop losing prop zincs - it certainly is a good change. There are however always new lessons to learn - sometimes the hardway. I managed to rip off a zinc and the back half of the bronze collar by wrapping a line on both props - don't ask. Anyhow that machine screw facing aft from the bronze collar does provide a vulnerable lever to tear off part of the bronze. Have an extra. And note that the opening for the insertion of the cotter pin does not extend far enough on all of the bronze collars available so some require some drilling or filing the bronze to line up with the prop shaft hole. Hope you miss this experience. Brian and Nancy Strong

[cruisingbluewater]

If you buy zincs online, I suggest www.boatzincs.com. They are much less than West Marine.

Stuart

[Bargain Bill]

Excuse my ignorance, but I've replaced the prop zincs 2x on my MV34 #029. I use the "bullet" zincs that are held to the shaft end by an allen head bolt. The first time, I had to drill the holes larger because the old bolts stripped the threads. Other than that we have had no problems in 600 hrs of cruising. I did not see a brass fitting of any kind. What am I missing?

[duetto]

my guess is that everyone is talking about the bronze prop nut which has a "slotted witch's hat" at its rear end. this came threaded to accept "conehead" propshaft zinc using an allen bolt. some of us fitted an allen bolt from inside the witch's hat and then a stop nut. this has prevented us from losing anymore zincs.

[MV Dana Louise]

Bill and Fran. The stripped thread problem
Is one of the reasons to reverse
The machine screw so the vulnerable
Bronze thread no longer takes the load.
Sounds like you are ok for now anyhow.
Brian