Need some quick Zinc/corrosion help and suggestions

nk235 · #1 01-24-2009

I know there is a wealth of information about electrolysis and zincs and bonding and I have been trying to read some of it but I am sort of pressed for time....

My 84' Morgan 323 is new to me and as I bought it last Spring. I am storing it in the water at my local dock. Today when I went to check on it I took a close look at the shaft and stuffing box. I can't remember exactly what they looked like during the summer as the boat is still so new to me but today it looked very green and pretty corroded and I am almost positive it didn't look that way when I kept it on my mooring during the spring summer and fall. I changed the shaft zinc in the end of August so it has been about 6 months.

One major difference of how I keep the boat is that in the offseason it is in a slip, connected to shore power with a temp regulated heater in the cabin connected to the boats electrical system. Anyway I am going down to the boat again tomorrow with someone who knows a lot about boats and maintenance and I think I will also be able to see the condition of the shaft zinc since it will be calm winds tomorrow. (today was pretty windy and the water was turbulent so I could not see the condition of the zinc as it was very blurry)

So my question is lets say the water is clear and I can see the shaft zinc tomorrow and if it is very eaten away what are my options? The marina it is at now has no lift, the boat is shrink wrapped and there is no way I am de-winterizing it and sailing it somewhere else anytime before mid April. Short of paying a fiver with a dry suit, is there anyway I could hang a zinc around the shaft with metal wire? Place a zinc somewhere else inside the boat that is accessible? I honestly think the issue is related to the Shore Power since I never saw this the season out on my mooring and I don't want it to ruin my boat because of stray current. Any suggestions or help would appreciated.
Thanks in advance.

lynger1 · #2 01-24-2009

One major difference of how I keep the boat is that in the off season it is in a slip, connected to shore power with a temp regulated heater in the cabin connected to the boats electrical system.

I have that problem long time ago
If you use shore power in winter on blocks with no earth
You need to earth boat with 60cm brass bar hit it in the ground below boat and earth shore power from boat to this

Other thing you can do is put clamp on prop-shaft with earth during storage
Hope this Will solve you're problem

nk235 · #3 01-24-2009

Quote:

Originally Posted by lynger1

One major difference of how I keep the boat is that in the off season it is in a slip, connected to shore power with a temp regulated heater in the cabin connected to the boats electrical system.

I have that problem long time ago
If you use shore power in winter on blocks with no earth
You need to earth boat with 60cm brass bar hit it in the ground below boat and earth shore power from boat to this

Other thing you can do is put clamp on prop-shaft with earth during storage
Hope this Will solve you're problem

Thanks for the suggestion but the boat is actually in the water in a slip - not on land on blocks.

lynger1 · #4 01-24-2009

Quote:

Originally Posted by nk235

Thanks for the suggestion but the boat is actually in the water in a slip - not on land on blocks.

Same apply earth to shore power suply
I asume you get 3 pin supply + and- and earth make a return fromm drive shaft to this

camaraderie · #5 01-24-2009

Green is not a big problem...but get some good light on the area and inspect closely for any sign of pink which is a big problem.
If the zinc has not been changed since last spring...you are overdue for an inspection but with cold water and NO pink...you can probably hold off a bit. If there IS electrolysis going on, you can hang a zinc fish on a wire from a grounded part of the boat to overboard to try minimize damage but that is no guarantee.
The only way to truly protect the shaft is with a shaft zinc...which means a diver if you are still concerned after a close inspection.

nk235 · #6 01-24-2009

Cam,
Thanks for the suggestion. I will try and take some pictures tomorrow morning and will post them so if you happen to check back maybe you can let me know what you think. Also the zinc has been changed at the end of the summer, late August 08' - not the spring but either way I should be able to se the status of it tomorrow assuming the water in the slip is nice a calm.
Thanks again

Fstbttms · #7 01-25-2009

It would have to be a fairly extreme situation for your zinc to have depleted and serious damage to your running gear occur within 5 months. Not that it couldn't happen, but it would be unusual. You are probably fine. I don't know what diver rates are like in your area, but here it would cost you in the vicinity of $50.00 for an inspection. If your diver is reasonable (like me

) that price would include the installation of a zinc or two (zincs would likely be extra). Couldn't hurt to carry two on your shaft instead of one, BTW.

nk235 · #8 01-25-2009

Fstbottoms - if you lived here I would take you up on that offer in a heartbeat. It is also 17 degrees F here today though so I would need to find a diver with a dry suit.

Ok so here is the update. I uploaded a picture of what the shaft looks so now that you can all see it firsthand, what do you think? Also I coudl see that the zinc on the shaft is very deteriorated and half missing so I know there is a problem some where.

I also found out that the through holes on the boat are not bonded, but they look to be in good shape. Just the shaft is what scares me. What I am doing for the time being is I turned off the shore power and disconnected the cord. I am going to polish the inside portion of the shaft with a stainless steel brush and bronze polish. I am then going to get one of those fish zinc things with a 15' long wire. I am going to wrap the end of the wire around the inside portion of the shaft which is shown in the picture and then run the wire out into the cockpit and over the side where the fish zinc will sit in the water. Do you think this will help?

Thanks again for everyones responses

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sailingdog · #9 01-25-2009

NK235—

That kind of surface corrosion is pretty normal for a bronze shaft, especially inside the boat. Exactly where are you seeing a zinc in this photo. Zincs are normally on the exterior portion of the shaft, as the need to be immersed in water to function properly. Occasionally, you'll see one on a shaft inside the boat, but that is generally as a safety measure, so the prop shaft can't fall out....but not to prevent corrosion.

camaraderie · #10 01-25-2009

NK...I don't see anything unusual there. No worries till spring based on that picture...but you might want to get some better hose clamps on that stuffing tube.