Reply
 
Thread Tools Search this Thread Display Modes
 
Old 02-12-2022, 03:25 PM   #1
Member
 
City: Bigfork
Vessel Name: Perseverance
Vessel Model: Jefferson 53
Join Date: Dec 2021
Posts: 16
Zincs

I am new to Trawler forum. We have purchased a Jefferson 53 And I have recently had a diver install 16 new zincs. And some of my friends have indicated that thatís a lot zincs. My boat broker suggested that I use or consider aluminum instead of zincs. Our boat is in saltwater and we plan to keep it there indefinitely. I have ordered a new set of sinks from boatsinks.com and I find that the price is 1/2 of what the diver charged me. Also the diver would like me to set up a maintenance program with him. The diver charged me $300 to install the zincs and do a partial cleaning of the boat. That seem like a reasonable charge for the diver. Any thoughts on the above regarding divers and zincs would be appreciated.
monti is offline   Reply With Quote
Old 02-12-2022, 03:46 PM   #2
TF Site Team
 
Comodave's Avatar
 
City: Au Gres, MI
Vessel Name: Black Dog
Vessel Model: Formula 41PC
Join Date: Jul 2015
Posts: 16,399
I used to buy my own zincs and have the diver install them. He would change a small fee to install them. But it was better than paying his price for the zincs. He has to make a living and stocking the zincs does cost. I donít remember what he charged for the install but it worked out cheaper.
__________________
Boat Nut:
If you are one there is no explanation necessary.
If you arenít one, there is no explanation possible.
Comodave is online now   Reply With Quote
Old 02-12-2022, 05:18 PM   #3
Valued Technical Contributor
 
DavidM's Avatar
 
City: Litchfield, Ct
Join Date: Aug 2012
Posts: 6,333
When I kept my boat in the water and had the bottom cleaned every other month, I would keep 1 or 2 of each zinc type on the transom. When the diver came to clean, he would change the bad zincs at no extra charge using the ones I provided.

As I recall, he changed the prop shaft zincs mostly, never the trim tab zincs and maybe every year or so for the transom zincs. For this single engine boat, I had one prop shaft zinc, two trim tab ones and two transom zincs for a total of five. Sixteen sounds crazy.

David
DavidM is online now   Reply With Quote
Old 02-12-2022, 05:45 PM   #4
Art
Guru
 
Art's Avatar
 
City: SF Bay Area
Vessel Model: Tollycraft 34' Tri Cabin
Join Date: Feb 2011
Posts: 12,068
Yo Monti - Welcome!

I guess your boat is kept in 100% saltwater??

IMO... too many zinc is better than too little. Please tell us where you find places for "16" new zincs... does seem like an awful lot.
Art is offline   Reply With Quote
Old 02-12-2022, 06:01 PM   #5
Guru
 
Simi 60's Avatar
 
City: Queensland
Vessel Model: Milkraft 60 converted timber prawn trawler
Join Date: Jul 2016
Posts: 4,374
To many annodes can cause more problems than they solve, especially on timber.
__________________
Everything on a boat is broken, you just don't know it yet
Full time cruising is repairing boats in exotic locations
Simi 60 is offline   Reply With Quote
Old 02-12-2022, 06:17 PM   #6
TF Site Team
 
slowgoesit's Avatar
 
City: Puget Sound
Vessel Name: Muirgen
Vessel Model: 50' Beebe Passagemaker
Join Date: May 2019
Posts: 1,981
Our boat is 3' shorter, only one engine, and has a grand total of three (3) zincs. One on the rudder, one on the swim step support, and one on the transom. Prop is CPP, so no place to hang zinc, but shaft is bonded to rest of boat bonding system.

I to am curious where the diver found places to attach 16 zincs?!? If twin screw, I can see maybe MAYBE eight . . . but SIXTEEN?!?
__________________
Vessel Name: Muirgen
Vessel Model: 50' Beebe Passagemaker
slowgoesit is offline   Reply With Quote
Old 02-12-2022, 07:37 PM   #7
Member
 
City: Bigfork
Vessel Name: Perseverance
Vessel Model: Jefferson 53
Join Date: Dec 2021
Posts: 16
Jefferson 53 has 14 zincs. 4 in the rudders, 2 on the transom, 4 on the two shafts, 2 on the trim tabs and 2 on the bow thruster.
My diver was mistaken…still that is a lot of zincs!
monti is offline   Reply With Quote
Old 02-12-2022, 07:49 PM   #8
Guru
 
O C Diver's Avatar
 
City: Fort Myers, FL... Summers in the Great Lakes
Vessel Name: Slow Hand
Vessel Model: Cherubini Independence 45
Join Date: Dec 2010
Posts: 11,096
That sounds about right. Don't forget the anodes in the engine(s) and generator heat exchangers and transmission coolers if so equipped. Zinc is best for saltwater; aluminum for brackish but good for saltwater and freshwater; magnesium is best for freshwater.

Support your local bottom cleaner. Timely cleanings and anode replacements will pay for themselves in bottom paint longevity and repairs from missing anodes.

Ted
__________________
Blog: mvslowhand.com
I'm tired of fast moves, I've got a slow groove, on my mind.....
I want to spend some time, Not come and go in a heated rush.....
"Slow Hand" by The Pointer Sisters
O C Diver is offline   Reply With Quote
Old 02-12-2022, 07:55 PM   #9
Member
 
City: Bigfork
Vessel Name: Perseverance
Vessel Model: Jefferson 53
Join Date: Dec 2021
Posts: 16
I assume divers use add on’s to the price of their services. I have no problem with that if it’s part of the industry’s practice. Still learning…
monti is offline   Reply With Quote
Old 02-12-2022, 08:07 PM   #10
Guru
 
O C Diver's Avatar
 
City: Fort Myers, FL... Summers in the Great Lakes
Vessel Name: Slow Hand
Vessel Model: Cherubini Independence 45
Join Date: Dec 2010
Posts: 11,096
In the relative scheme of things, anodes are a minimal cost. If you're not hauling annually, let the diver supply them. I never want to be thought of as a PIA customer when I need the diver ASAP.

My preference and what many consider the best zincs are Camp.

Ted
__________________
Blog: mvslowhand.com
I'm tired of fast moves, I've got a slow groove, on my mind.....
I want to spend some time, Not come and go in a heated rush.....
"Slow Hand" by The Pointer Sisters
O C Diver is offline   Reply With Quote
Old 02-12-2022, 08:22 PM   #11
Guru
 
ancora's Avatar
 
Join Date: Dec 2007
Posts: 3,952
I would consider an Evergard or similar system to eliminate all of those zincs and have just two "plate zincs" on the transom. I have had the Evergard system on my trawler for 22 years and can't complain.
ancora is offline   Reply With Quote
Old 02-12-2022, 08:36 PM   #12
Art
Guru
 
Art's Avatar
 
City: SF Bay Area
Vessel Model: Tollycraft 34' Tri Cabin
Join Date: Feb 2011
Posts: 12,068
Quote:
Originally Posted by Simi 60 View Post
To many annodes can cause more problems than they solve, especially on timber.
Yup - On timber! Far as I know... not on fiberglass.
Art is offline   Reply With Quote
Old 02-13-2022, 10:14 AM   #13
Guru
 
City: Olympia
Vessel Name: Rendezvous
Vessel Model: Blue water 40
Join Date: Aug 2021
Posts: 594
a proper survey of the underwater metals using a meter and a half cell is the best way to see if you're in the zone as far as anodes are concerned.
it is definitely possible to over or under protect any boat that has power systems.
i typically let the diver supply the zincs. the exception would be anything out of the ordinary. the thruster zinc is drilled specifically for it's mountings, so i supply that one. i keep every zinc the boat uses in my spares in case he doesn't have them on hand as well.
Bmarler is online now   Reply With Quote
Old 02-13-2022, 10:45 AM   #14
Art
Guru
 
Art's Avatar
 
City: SF Bay Area
Vessel Model: Tollycraft 34' Tri Cabin
Join Date: Feb 2011
Posts: 12,068
Quote:
Originally Posted by Art View Post
Yo Monti - Welcome!

I guess your boat is kept in 100% saltwater??

IMO... too many zinc is better than too little. Please tell us where you find places for "16" new zincs... does seem like an awful lot.
Still do not understand 16 zinc locations on a boat your size... can you list them for me/us?

I have 9 under hull anodes in following locations... some say 4 too many; i.e., only need one each shaft and none on stainless trim tabs. But, like I mentioned in my quote above. "IMO... too many zinc is better than too little."

- Two on each shaft
- one on each rudder
- one on each trim tab
- A "drivers dream" center on transom
Art is offline   Reply With Quote
Old 02-13-2022, 11:48 AM   #15
Guru
 
Irish Rambler's Avatar
 
City: NARBONNE
Vessel Name: 'Snow Mouse.'
Vessel Model: BROOM FLYBRIDGE 42.
Join Date: Apr 2014
Posts: 1,704
The Mediterranean is one of the saltiest seas but we only use one lead on the shaft and 2 on the rudder, all the seacocks are bonded and we only lift out once every 5 years.
Aluminium will disappear very quickly in salt water and normally only used in fresh.
Irish Rambler is offline   Reply With Quote
Old 02-13-2022, 12:37 PM   #16
Guru
 
BandB's Avatar
 
City: Fort Lauderdale. Florida, USA
Join Date: Jan 2014
Posts: 21,451
Keep in mind, this was a first time change. Most of those will seldom need replacement. Sounds like your diver was reasonable and thorough.

As to the price of anodes, they also vary in quality, but the problem is your diver is likely paying more locally than boatzincs sells them for. He's likely then only getting about a 20% discount from a high retail price. So, he is not profiting as much as you may believe.

We prefer to keep our own anodes in inventory, not to save money, but to always be sure we've got the exact one we want, full OEM. Then we're willing to pay generously for inspection and replacement. You likely paid less for replacing them since your diver got a profit on selling them to you.

I would let the convenience and quality be the determining factors and not worry about what are ultimately minor cost differences. Having a quality diver is extremely valuable.

And then even with the best of divers, I would have a camera of some sort (Go Pro works fine) and regularly examine before and after. Not secretively, but even with him if you're there at the same time, just taking care in the bot bottom, and keeping an eye on bottom paint and underwater gear.

Now we get lots of bottom cleaning and none of ours involves any scraping. If they have to scrape, you're not doing it often enough. Scrapers are not even allowed on site. Only soft materials. Our yard is amazed at the time we get from our bottom paint.
BandB is offline   Reply With Quote
Old 02-13-2022, 10:44 PM   #17
Guru
 
kthoennes's Avatar
 
City: Sioux Falls, South Dakota
Vessel Name: Xanadu
Vessel Model: Mainship 37 Motor Yacht
Join Date: Oct 2013
Posts: 2,032
I have five. Two prop shafts, one transom, one on each rudder. 14 sure sounds like a lot to me, and I've always been taught more is not always better.
kthoennes is offline   Reply With Quote
Old 02-14-2022, 12:32 AM   #18
Art
Guru
 
Art's Avatar
 
City: SF Bay Area
Vessel Model: Tollycraft 34' Tri Cabin
Join Date: Feb 2011
Posts: 12,068
Quote:
Originally Posted by kthoennes View Post
I have five. Two prop shafts, one transom, one on each rudder. 14 sure sounds like a lot to me, and I've always been taught more is not always better.
OP - Says... "I have recently had a diver install 16 new zincs."

Let's conjecture

2 on each of 2 shafts = 4 [actually, only one on each shaft if okay]
1 on each of 2 rudders = 6 total
1 each on each trim tab = 8 total [actually, stainless tabs need none]
1 on each of a bow and stern thruster = 10 total

Sooo - where are the other 6 anodes placed?? Did the diver count correctly regarding anodes replaced - just wondering??!!
Art is offline   Reply With Quote
Old 02-14-2022, 07:49 AM   #19
Senior Member
 
City: St. Petersburg
Join Date: Oct 2007
Posts: 333
Sacrificial anodes

I am an experienced and certified corrosion technician. There are three types of material used for sacrificial anodes in the marine industry: zinc, aluminum and magnesium.

The traditional zinc anode can only be used in salt water; aluminum anodes can be used in salt or brackish water and magnesium anodes can only be used in fresh water.

On the West Coast of Florida, I recommend that my clients switch from zinc to aluminum anodes for the following reasons:
1. Pound for pound they produce 50% more amp-hours than zinc. Therefore; an equally sized aluminum anode will last about 50% longer.
2. Aluminum anodes produce about 0.050mVDC more potential measured against a standard reference anode. Since the potentials we deal with in the galvanic series are very small, any increase in protective potential is usually good.
3. Zinc anodes include cadmium in the manufacturing process. Cd is a heavy metal that stays present as the anode corrodes, sinks to the bottom, and then works its way up the food chain. Heavy metals are not good for humans to ingest.
4. Aluminum anodes cost about the same or are slightly less expensive than zinc anodes of the same size and are available at my local West Marine.

The above are general comments. Fiberglass, aluminum, steel and wood boats all have cathodic protection requirements unique to the basic hull material. Aluminum underwater components, e.g.; sail drives, Volvo IPS drives and Zeus pod drives all have unique cathodic protection requirements.

Finally, the diver that performs your hull husbandry is the first line of defense against corrosion issues and is the early warning system for the onset of the sometimes extremely destructive stray current corrosion. Heed the advice of a competent diver.
__________________
Charlie Johnson
ABYC Master Technician
CharlieJ is offline   Reply With Quote
Old 02-14-2022, 06:00 PM   #20
Art
Guru
 
Art's Avatar
 
City: SF Bay Area
Vessel Model: Tollycraft 34' Tri Cabin
Join Date: Feb 2011
Posts: 12,068
Charlie... good to hear from an expert.

Can you tell me... is it basically ok to use zinc in "non hot" areas of freshwater as long as you monthly [or there abouts in your service schedule] fully scrape clean all the gathering oxidation that forms on zinc's surface in fresh water?

In other words, as long as zinc's surface is kept clean doesn't zinc still perform as an anode in freshwater?

Thanks in advance for your reply. - Art
Art is offline   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


» Trawler Port Captains
Port Captains are TF volunteers who can serve as local guides or assist with local arrangements and information. Search below to locate Port Captains near your destination. To learn more about this program read here: TF Port Captain Program





All times are GMT -5. The time now is 09:48 AM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2022, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2006 - 2012