Effect of Prop Antifouling on Prop Anode Wear?

[Dockhead]

Originally Posted by UNCIVILIZED

I have no reason to BS you on this. It's something that I've done, many times over. As have a lot of other guys I know. Because sometimes it's just mandated by the job, & or circumstances.
I was Navy for many years, & sometimes the things you do/have to do are "interesting". Albeit I've been in 40 deg. water since then, too. For extended periods. And plenty of people can attest to as much. Although there seems little point in going into detail, given the response to my statements already.

I don't have the slightest doubt in what Uncivilized say, but as A64 says -- it's not for ordinary people who aren't in top physical condition and haven't had the rigorous training of the Navy.


People dive here for sure, but they do it in dry suits, they are well trained for it, and they are very, very careful. In all my years here I have never seen a single person swimming in the sea in the winter time -- not once.

When Pete dove my prop a couple of years ago, he was wearing a dry suit although it was already almost May and the air was warm.


It's not at all like in Florida where you just dive in with a snorkel and frolic under your boat as you like.

[deblen]

Originally Posted by UNCIVILIZED

I have no reason to BS you on this. It's something that I've done, many times over. As have a lot of other guys I know. Because sometimes it's just mandated by the job, & or circumstances.
I was Navy for many years, & sometimes the things you do/have to do are "interesting". Albeit I've been in 40 deg. water since then, too. For extended periods. And plenty of people can attest to as much. Although there seems little point in going into detail, given the response to my statements already.

I scuba dove (recreation) in my younger years with wetsuit-no drysuits affordable then.
I also swam,as a youth,in these waters. "Swimming" consisted of diving off a wharf & swimming like hell for the ladder-nobody lingered long in 40F water!
If I was confronted with a life or death situation-yes I would enter the water-but definitely not to change a zinc.
You are tougher than me!!

Cheers/ Len

[a64pilot]

I believe an average person, diving into 5 or so C water may well drown, the gasp reflex of hitting water that cold will have them inhale water, or so I have always been told.

I have never been as cold as many of you guys, but playing Army in Bosnia in 1995 and one year in Korea has taught me that I equate cold to pain, and I never want to be cold again.

You people that jump voluntarily into cold water, are nuts

[deblen]

Originally Posted by a64pilot

I believe an average person, diving into 5 or so C water may well drown, the gasp reflex of hitting water that cold will have them inhale water, or so I have always been told.

I have never been as cold as many of you guys, but playing Army in Bosnia in 1995 and one year in Korea has taught me that I equate cold to pain, and I never want to be cold again.

You people that jump voluntarily into cold water, are nuts

Falling unexpectedly into cold water triggers the "gasp" reflex in most cases.
Your CNS goes into auto survival mode very close to a fight or flight panic attack. Your extremities become basically useless & uncontrollable & your mind goes fuzzy. This effect lasts for a minimum of 30sec & is the cause of most cold water drownings-proven by studies.
If you plan to jump into cold water,this reaction is minimized/negated,because your mind is prepared.
Yes-there are many who have swam the E. channel & other similar waters,but,as said,they have conditioned themselves well beforehand.It can be done with proper training & conditioning(Navy,etc) but is not recommended for the avg. person. Even if you survive the initial shock,heat loss is so fast in 40F water,that your core temp. drops to the fuzzy mind level in less than an hour at best.
No offense to Uncivilized or anyone else.
I just don't want the warm water folks to think they can just jump in like they do in tropical waters.
I have seen too many deaths in my life around this fishing area that were a result of shock and/or hypothermia before the boat could retrieve the person-good swimmers too-in a matter of minutes.
Some of them died on deck or on shore after retrieval-due to hypothermia.
Cold water is no joke-stay safe

[UNCIVILIZED]

Originally Posted by a64pilot

Some really tough people can actually become acclimatized to water temps that will kill us wimps.
There is this one long distance swimmer female I'm thinking about, I think she regularly swims for hours in water temps that would kill most people in minutes?
I think her circulatory system has actually changed from an average person and maybe some other actual physical differences?

I cut this from Wikipedia

Cox is perhaps best known for swimming 2h 5 mins in the Bering Strait on 7 August 1987,[3] from the island of Little Diomede in Alaska to Big Diomede, then part of the Soviet Union, where the water temperature averaged around 43 to 44 °F (6 to 7 °C).

Well, I haven't been in water like that quite as long. Just past half of that mark, in the same temps.
Yeah, it's cold, albeit not like when you go in when there's ice... and some of the "trick" is in not minding. But along with that, one can learn to turn up their internal rheostat up a few notches. As well as a few other things which your body tells you to do in order to adjust to it. If you're listening to it/can listen to it.
Still, you know how it feels when you eat ice cream too fast. Well, it doesn't stop your WHOLE head from feeling like that. Ouch!

No special training, although a GF who'd taught yoga for 25yrs was amazed at some of what I could do. With cold, & learning much of what it took her years to pick up, in only minutes or hours.
Nor was I in great shape at the time, & I was 35. And had been out of the USN for quite a while.

PS: No, it's not exactly something that I'd recommend to most. And yes, I know of a few people who can teach it as a skill. But you also have to be the "right" student.

[Snowpetrel]

Since were boasting about cold water... I Spent an hour or two diving in antarctica to bolt the lower rudder bearing back on once. I wore a cheap kayaking drysuit and a fair few layers of polerfleece under it. Luckily i borrowed some dive gear and a wetsuit hoodie from another yacht.

Had a big pot of hot water on the aft deck to thaw out my hands.

Worked fine, once I added enough weights to my legs to stop them floating up.

I snorkled on it to check the bolts were still tight before we headed back to ushiua. No hoodie. Serious icecream headache. Nasty.

Had a nice midnight sun new years eve party as well. A wee bit of skinny dipping in the icy water was in order... cold but ok for a minute or two if you got you head out quickly. Maybe the alcohol helped?

[Rustic Charm]

Originally Posted by GILow

Ouch! Not a nice price.

We are paying around AU$150 for the application by our yard master. I could probably reduce the price if I went DIY but I trust the yard master to do a better job than I ever will.

Sent from my iPad using Cruisers Sailing Forum

I dont think you will lesson the price because if you dyi you would have to buy a whole system. Propspeed is around $400 i believe its just a rediculous price for a small prop.

[clownfishsydney]

As far as I know you cannot buy Propspeed in Australia unless you are a person who anti-fouls boats as a profession. In any case, as pointed out, the cost of buying the minimum amount is much more than paying someone to do it for you.

[Dockhead]

Incidentally, my massive bronze P bracket probably has more area than my prop does.

Maybe this a case of bronze vs stainless shaft? Maybe that's what's eating up my hull and shaft anodes? Maybe I should paint it?

I was looking at it today longingly (I'm on the hard at Cowes) thinking what a great ground plate it would make for the SSB.

[Rustic Charm]

Originally Posted by Dockhead

Incidentally, my massive bronze P bracket probably has more area than my prop does.

Maybe this a case of bronze vs stainless shaft? Maybe that's what's eating up my hull and shaft anodes? Maybe I should paint it?

I was looking at it today longingly (I'm on the hard at Cowes) thinking what a great ground plate it would make for the SSB.

Have you had your boat prifessionally tested for leaking currant? You seem to be dismissing this as the cause, and yet to me it woukd be the first thing to discount.

[savoir]

I feel like I'm changing the subject but it seems to me that the zinc issue might be caused by too much stray electricity earthing out through the prop shaft.

[fstbttms]

Originally Posted by Dockhead

Incidentally, my massive bronze P bracket probably has more area than my prop does.

Maybe this a case of bronze vs stainless shaft? Maybe that's what's eating up my hull and shaft anodes?

The shaft is isolated from the strut (or P-bracket, as you Brits call it) by the cutless bearing. There is no electrical contact between the two.

[Rustic Charm]

Originally Posted by fstbttms

The shaft is isolated from the strut (or P-bracket, as you brits call it) by the cutless bearing. There is no electrical contact between the two.

Well, i was wondering what a P Bracket was, now i know

[Dockhead]

Originally Posted by Rustic Charm

Have you had your boat professionally tested for leaking currant? You seem to be dismissing this as the cause, and yet to me it would be the first thing to discount.

I've dismissed it because the anode wear is very consistent whether the boat is connected to shore power or not, batteries isolated or not, isolation transformer or not, fresh water or salt, etc.

[Dockhead]

Originally Posted by fstbttms

The shaft is isolated from the strut (or P-bracket, as you Brits call it) by the cutless bearing. There is no electrical contact between the two.

Right. Duh . . .

Edit -- no, wait a minute -- it IS electrically connected to the shaft. They are bonded together. Both connected to the hull anode; the shaft via a kind of brush contact.