I tend to agree with timbalfour when he says; 

"The plate you show in your pics,looks more like a grounding plate (for SSB/ham radio?). If you scrape away at it,you may find it's actually

sintered bronze."

I don't have anything like this on Tondelayo so I imagine if you don't have HF radio you probably don't need it.

It is definitely a zinc.  All of the thru-hulls were bonded to it.  Since I don't plan on bonding the thru-hulls to it this time around, I was just curious if having that extra zinc in the water was worth it, or if I should just glass in the holes.

"The plate you show in your pics,looks more like a grounding plate (for SSB/ham radio?). If you scrape away at it,you may find it's actually

sintered bronze."

I don't have anything like this on Tondelayo so I imagine if you don't have HF radio you probably don't need it.

I don't plan on bonding my thru-hulls.  Is there any remaining benefit to keeping the plate zinc on the side of the boat?

Erick said:

This is the only zinc I could find, and it seemed to be just for thru-hull bonding (plate zinc):

I am also curious about what zincs other DE owners have.  There was no sinc on the shaft (unless the prop nut was a zinc), which worried me.  My prop/shaft:

 

Hi Erick,

I imagine you have sorted your sacrificial anode by now but thought I'd add this photo of what yours might have looked like when first installed just in case anyone else was wondering.

I have now changed Tondy's to a little bit of a diferent set up (can't find a photo just now) whereby you can just undo a grubscrew at the rear and remove the old anode then put a new one on. I imagine I'll be able to do it in the water (as long as I don't drop the grub screw) although I did put a fair bit of "Locktite on it.

Dave

 If your boat is properly wired/grounded, this should be enough. the only other thing you should worry about is any bronze thu-hulls/seacocks which could be vulnerable if the wiring isn't correct. There is a lot of litterature on boat wiring - especially about the 'green wire' controversy. If you have a/c on the boat (and used at the dock), it is very important to get this right, as dock's wiring often leaves much to be desired. The grounds on the dock run a long way and are often too long/inadequate so that any problem will find its way to the shortest route (hopefully, the water).

In our warm water, especially on the dock, where there is probably a certain amount of 'stray' electricity (you have to be aware of nearby boats being inadequately wired) - we get throuhg two shaft zincs a year. We can replace them  under water here.

Marelon thru-hulls/seacocks alleviate some of the problem. I've replaced some of mine with these on several boats. On our Peterson44 I was suspicious because of obvious bad wiring that had been gerry-rigged over the years. I took a hammer to one of the old bronze seacocks and it disintegrated!! I changed them all - some 15 of them!

A long time ago in England, I bought a 28' ferrocement boat (which I subsequently covered some 20,000 miles in). She had been sitting in the mud (a tidal berth) for a year and the prop had acually dropped off, together with the exposed part of the shaft!! The problem with stainless is that you don't see what's going on (unlike mild steel and aluminium), I t often doesn't show on the surface. On our 'Ingrid', the shaft was bronze, as were the pintles/gudgeons and seacocks - so there was no problem.

The plate you show in your pics, looks more like a grounding plate (for SSB/ham radio?). If you scrape away at it, you may find it's actually

sintered bronze.

Tim - 'Pelli' DE32

It's coming up on spring and I am planning on careening Seabird to paint her bottom. I am a new enough owner that I havent see her underside. Can anyone tell me what size and type Zincs I will need?

 

Thanks

Travis

Good luck,

Chuck

I don't have any pictures of it that I'm aware of but on valkyr we have one of the small cone zincs that screws over the end of the prop shaft behind the prop. I need to change ours as it is pretty eaten up. I have thought about putting one around the propshaft as well.

Scott

I am also curious about what zincs other DE owners have.  There was no sinc on the shaft (unless the prop nut was a zinc), which worried me.  My prop/shaft:

Thanks

Travis