Barnacle fouling on Prop

[Hiker_00]

Something has changed this year with my prop. This is year three so there's not a lot to base this on but I've never had this growth on my shaft and propeller. Normally the zincs are gone or barely there. That's not the case this season and all these barnacles are unusual but this was an unusual season too.

This is on a 75 Sabre 28 moored and sailed in Penobscot Bay Maine. We did not use the boat much in June and July due to nasty weather. Commissioning included disassembling the external A4 attachments and clean/paint. Engine ran fine and no signs of electrical imbalances but I didn't look either.

In case you wonder, there's little play in the unknown aged cutlass bearing.

Any ideas?

Thanks
Tim
Rockport, Maine

[jayw]

June & July had terrible weather for sailing here in Plymouth, MA, too.
I think that the lack of use during the time that barnacle nauplii (free-swimming larval stage) were abundant and looking for some substrat to attache to and grow on accounts for the difference. I would guess that in most years, you probably use the propeller enough to dislodge the barnacle babies before they get a firm hold.

[CalebD]

This was an unusual year on the lower Hudson River as well. All the rains we had in June seemed to lower the salinity of the river (tidal estuary). I think that because of the lower salinity we had only smaller barnacles on our prop when we cleaned the hull in September, more slime then usual and lower salinity may have helped erode the zinc less as well.
Does a river empty into the bay you are moored in?

[Hiker_00]

No streams of merit but it really rained a lot in Rockland Maine in early summer. I was afraid I screwed something up. I'll ask around my harbor friends.

Tim

[Tommmmd]

Barnacles..

I walked by (I think)_ a prop in the yard that was so heavily encrusted I could not imagine the engine having much effect. I'm in the Sakonnet in Portsmouth RI. I paint my running gear rather that fight heavy growth so only get a little where it flakes off.. Painting has been the subject of many other posts.

Tom Drechsler
Nora Mae

[romantic comedy]

A little barnacle problem

I wish we could sympathize with your barnacle problem. Actually I just reread the original post and I do have a related comment-see bottom of post.

This is our prop after a summer in the waters of southwest Florida...
...after the wire wheel
Good News Honey! , I think this zinc will last another season.

My husband decided to pull the shaft on our Tartan 34 and clean the prop himself. Last time we had the diver clean it and top (motoring) speed was 4 knots.
So when the diver came last week, instead of cleaning the prop we had him pull the shaft. My husband then cleaned the prop with a wire wheel on the bench grinder. By the time the diver finished the rest of the hull the shaft was ready to go back in.
After these photos were taken (and the prop and shaft installed) top speed was 7+ knots using measured with an iphone and a GPS.
captain's note: atomic four power and indigo 3 blade on T34C. Divers are needed sometimes but I can clean the bottom from a dingy with a brush and or scraper. The prop is the thing that I cant get (yet). But spending $60 for a 20 minute cleaning job and then only getting poor performance is crazy. Another issue I have with divers is they charge by LOA. So I have a LOA of 34+ and a waterline of 25 foot with a 10' 2 beam. pick a new 34 foot boat and the bottom is probably twice the size. But that is sailing! It is getting so expensive. You can see a reflection of the boats bow in the photo.

I removed the coupling and removed and repacked the stuffing box. the water streams in but not that much. I put the stuffing box (the nut part) back on before the shaft was pulled. I followed the shaft with a 1" dowel that I put a little taper and bit of tape on. About 1 cup of water came in when the shaft was pulled. The shaft went in just as easy.
I want to start a discussion of ways to keep barnacles off the prop. I want to make a bag that I can put over the prop while it is at the dock. I never get barnacles in the centerboard case so I think this bag idea might work-but that is for another thread.

COMMENT: Hiker 00 You said that the zincs were mostly gone in the past years? right? And this year the zincs are not bad. So I am thinking that there may have been some current flow that may have kept the barnacles away in the past. I think products exist that set up some sort of current flow to keep the barnacles off (I dont know of the efficacy) -maybe you have a similar situation.
Also, I think that Indigo says not to use zinc on the prop and you will not have barnacles. I am not sure about that but maybe.
I just went to the Indigo electric site (atomic4.com) and he does say that no zinc will keep barnacles off the prop due to the galvanic situation between the SS shaft and the prop (an alloy of copper). There is a bit more-he talks about his prop being made of a silicon bronze and if run without zinc it would last approx 10 years. (but no barnacles) A " typical " prop would be ruined much sooner-according to Indigo.
I bought my Indigo prop november of 2001 and ran the ICW to fl and have had it in the water ever since with one 2 month haul out. I use a zinc. I get barnacles.

[CalebD]

Moron Zincs

The reason I mentioned all the rainfall we had up here in the north east is that on fresh water lakes they do not use zincs but rather a less 'noble' metal like magnesium instead. If the salinity was reduced by rainfall then the zincs on your shaft zincs may not have been as susceptible to erosion then in past seasons.
Fortunately for me the waters of the Hudson River are brackish and I have been able to re-use shaft collar zincs for about 2 - 3 years or so before replacing and my 2 blade prop never looked as bad as the picture above from a boat in FL waters where the water can be very high in salinity.
Romantic Comedy poses an interesting question about the use of zincs though. If there were no zinc(s) on your shaft then the stray electrical current they are meant to dissapate from your prop then it would be likely that barnacles would receive the stray current instead of the zinc. The only problem with this is that most props (& shafts) would be eaten away by electrolysis as well as the barnacles. In a sense, perhaps the zincs make your prop more comfortable for barnacles by disappating the stray electrical current they would receive if no zinc(s) were present.
Economically it is cheaper to replace zincs and not the prop and shaft every few years. That is why we use 'sacrificial zincs' to keep our boats drive shaft from breaking down. Barnacles be damned.
My $.02.

[keelcooler]

Under water metals need a protective coating to reduce fouling. Thirty years ago yard managers would mix pepper when painting antifouling on props. Twenty years ago they were applying STP oil, teflon or wax. Ten years ago Trilux or zinc coat. Today Speedprop is used by most yards. Next year who knows, egg whites and felt markers may make a comeback.

[rheaton]

This year I used some zinc-based anti-fouling spray paint on my prop and shaft. This was recommended to be by another person in our yard. Think the product was made by pettit. I was very happy with the results. I too have my boat in the Hudson. Perhaps it was some cyclical thing. I will use this again next year and report the results.

Take care, Russ

[CaptainMike]

Propeller Growth

I live in the Pacific NW and up here I found that the growth on my propeller can be really fast from May thru August. I have used Petit which I liked. It worked well on my rudder and trim tabs. I found that it came off my propeller after only a few weeks and I still had growth on my propeller. I started covering my prop with a PropPak underwater propeller cover which blocked the growth from reaching my propeller. It worked great and paid a diver 15 dollars to reinstall it. I also know some boaters who used PropSpeed. This product is expensive but seemed to keep most of the growth at bay.

If a boater does not use sacrificial anodes on their shaft/prop they would not have to worry about solid growth fouling their running gear. The big problem with that is your prop and shaft would get eaten away and you would face costly repairs. Nothing grows on the zincs because they are dissolving. Seeing growth on your prop and shaft may prove that your zincs are working properly.

Enjoy boating
Captain Mike

[wlevin]

Prop paint

We use a hard (non-ablative) bottom paint on our prop every year and it works very well. (That means perhaps one or two small barnacles near the hub at fall haul out.) It seems so easy and cheap that it makes me wonder why so few people do this. What are we missing here?
Bill and Jeanne
T34C #453
Otter

[positron]

My prop was about midway between Hiker's and RomanticComedy's last Fall. I had painted it with with a brush-on zinc enamel product (Interlux?). I used Petit HydroCoat on the bottom and it didn't work all that great either. I talked to the Petit rep at the Annapolis boat show and he said last year was particularly bad for slime buildup. The slime lets the barnacles get a foothold. This is especially the case if the boat doesn't get run for a few weeks in the late Spring, which was my case. He suggested weekly brushing. I suggested that I might keep looking for a paint that works...