Propeller anti-fouling?
 

You better announce to the dock master you are putting this type of
electrolisis on your boat.

This could initiate electrolisis and anodic reaction to most other boats
around you and dock and dock hardware and cause them to be the "sacrifical"
part in this corrisive situation.

If you add electrolisis, then all the anodes surrounding your boat will
attract those superfluous emissions and prematurely erode all the anodes.


Also, be careful with painting props for obvious reasons. Half way through
next motoring season when a shaft bearing fails due to introduced
unballanced wear on them, you can be assured that its cause is directly
related to your painting a balanced part therefore making it unbalanced and
causing vibrations and failing bearings or seals. Keep the prop ballanced.






"Noj Zang" wrote in message
...

"Bruce In Bangkok" wrote in message
...

It is not electrolysis I'm fighting, it is shellfish.


Let's try again. The link says:

The application of pulsed electric fields to water containing micro- or
macro-organisms has been proven to be a means of controlling the
population of these organism, or to stun them over a certain electric
field dependent time interval. The fact that the efficiency of this
control mechanism increases with decreasing pulse duration opens the
possibility to utilize microsecond pulse power technology for biofouling
prevention in cooling water systems. The advantages over other techniques
used for biofouling prevention such as its independence from chemicals,
the fact that it is possible to stun, rather than kill unwanted biofouling
species, that it does not generate shock waves which could affect the
structure of the cooling system, and that it can be installed like a
filter in front of an existing cooling system, without requiring any
changes in the cooling system, make the pulsed electric field technology
(PEFT) a strong contender to existing biofouling prevention methods. A
recent field study, where tidal water from the Elizabeth River in Norfolk,
VA, was treated by means of the pulsed electric field method, demonstrated
complete prevention of biofouling in pipes when the river water at the
intake of the pipes was exposed to electric field of 6.5 kV/cm with 770
nanosecond pulse duration. The efficiency was 1,400 gallons of treated
water per kWh, an increase in efficiency by more than a factor of three
compared to results presented at the 1996 Zebra Mussel Conference.
Experiments with even lower electric fields and correspondingly lower
energy consumption are under way. modeling results indicate that
efficiencies of more than 50,00 gallons/ kWh may be reached in fresh water
cooling systems.



The livestock fence shocker delivers said pulsed electric field of
required intensity. If the electric pulse is monophasic it delivers net
charge into the water, creating electrolysis. If the electric pulse is
biphasic (ie: capacitively coupled) it will deliver no net charge into the
water, avoiding electrolysis.

I, know, I know. It's not livestock that are giving your propellor
problems and the article only mentions zebra mussels in 1996.

But then you are the guy who wrapped electrical connections in tape for
frequently flooded aircraft runways and buried them in the ground, despite
the law saying those connections should be above ground in a hermetic box.
How many died because of that?

With barnacle growth the size of a medium shopping trolley fouling your
drive train at least you have the electrolysis problem solved as there are
no exposed metals to electrolyze.

I have studied this in depth at university in Bangalore.



Noj

Propeller anti-fouling?
 

Hi, Bruce, et. al.,

It's been in the water too long, now, so it's gone, but PropSpeed lasts a
couple of years. Go to their website for an education, but the simple
process is that it's too slippery for the critters to hold on to and they
sling off.

An etching primer applied to an 80 grit scuffed clean surface first, then
the other stuff on top of it. Basically yellow looking.

My prop stayed clean for the first couple of years in the water. When we
next haul, I'll use it again. Very satisfied.

L8R

Skip

--
Morgan 461 #2
SV Flying Pig KI4MPC
See our galleries at www.justpickone.org/skip/gallery !
Follow us at http://groups.yahoo.com/group/TheFlyingPigLog
and/or http://groups.google.com/group/flyingpiglog

"You are never given a wish without also being given the power to
make it come true. You may have to work for it however."
(and)
"There is no such thing as a problem without a gift for you in
its hand
(Richard Bach)

Propeller anti-fouling?
 

On Tue, 19 Jan 2010 19:36:34 +0700, Bruce In Bangkok
wrote:

On Tue, 19 Jan 2010 05:52:52 -0500, wrote:

On Tue, 19 Jan 2010 07:32:32 +0700, Bruce In Bangkok
wrote:

On Mon, 18 Jan 2010 16:28:05 +0100, "Edgar"
wrote:


"Bruce In Bangkok" wrote in message
m..

Has anyone tried any of the anti-fouling schemes intended for
propellers, and if so what was your experience?

The question comes about because I just had to dive on my prop and
clean it. When I got down there I discovered a mass of "clams" as big
as a bushel basket. Took two days to scrape them all off.

True, for one reason or another, the boat hasn't moved in the better
part of a year but still I don't believe I have ever seen as much
growth. Must be either global warming or high CO2 content :-)

In any event, it does make one think "there must be a better way".

Cheers,

Bruce
(bruceinbangkokatgmaildotcom)

Ordinary ablative antifouling might be better than nothing if you hardly use
the boat but it washes off in no time at all if you run the engine. I use
some expensive stuff in a spray can that Volvo produce for their underwater
units. This seems basically to be the same sort of antifouling but harder,
so it does not wash off so quickly. Also it makes a somewhat slick surface
so that barnacles find it harder to stay on while the prop is running.
I have a theory, not yet put to the test, that the very slick paint that has
been produced to make a wall graffiti-proof would be the way to go because
barnacles could not stick to it at all once the prop started to rotate.. The
reason I have not yet tested this idea is because the smallest quantity that
I have found for sale is about 10 gallons.


You are correct that normal anti-fouling paint doesn't stay on the
prop however several paint companies are making a paint specifically
for propellers. The recommended procedure is to (1) sandblast or grind
the propeller to a specific surface finish; (2) clean the propeller
chemically clean; (3) apply a specific primer and finally (4) apply a
specific anti-fouling paint. The whole procedure is involved and the
paint is expensive and apparently deviating from the specified
procedure results in failure. Thus my questions.

Cheers,

Bruce
(bruceinbangkokatgmaildotcom)

Normal anti-fouling should not be applied to a propeller. Normal
anti-fouling paint contains copper and your prop will get eaten.

I have no idea what the "propeller paint" is but it is certainly
recommended for propellers so I assume that it is compatible with
bronze.


I agree.

Propeller anti-fouling?
 

Wait a minute guys. I don't think we should just blow this guy off. There is logic to what he says. Although his language is not
clear, I think I understand what Noj is saying. When I first read about this technology, I was also very concerned with
electrolysis, but with after thought, he stated that he capacitively couples the charge. This electrostatic discharge is
effectively AC with negligible polar current draw. If you folks remember there was an episode on the "Mythbusters" where they
tried to corrode through a prison steel barred widow using electrolysis. At the end of the episode, there was negligible induced
corrosion with AC applied, yet a great deal of corrosion was induced with a simple battery. I do not believe this system will
induce a problem. It is certainly worth a test. Bruce, you're on.
Steve

" Tuuk" wrote in message ...
You better announce to the dock master you are putting this type of electrolisis on your boat.

This could initiate electrolisis and anodic reaction to most other boats around you and dock and dock hardware and cause them to
be the "sacrifical" part in this corrisive situation.

If you add electrolisis, then all the anodes surrounding your boat will attract those superfluous emissions and prematurely
erode all the anodes.


Also, be careful with painting props for obvious reasons. Half way through next motoring season when a shaft bearing fails due
to introduced unballanced wear on them, you can be assured that its cause is directly related to your painting a balanced part
therefore making it unbalanced and causing vibrations and failing bearings or seals. Keep the prop ballanced.






"Noj Zang" wrote in message ...

"Bruce In Bangkok" wrote in message ...

It is not electrolysis I'm fighting, it is shellfish.


Let's try again. The link says:

The application of pulsed electric fields to water containing micro- or macro-organisms has been proven to be a means of
controlling the population of these organism, or to stun them over a certain electric field dependent time interval. The fact
that the efficiency of this control mechanism increases with decreasing pulse duration opens the possibility to utilize
microsecond pulse power technology for biofouling prevention in cooling water systems. The advantages over other techniques
used for biofouling prevention such as its independence from chemicals, the fact that it is possible to stun, rather than kill
unwanted biofouling species, that it does not generate shock waves which could affect the structure of the cooling system, and
that it can be installed like a filter in front of an existing cooling system, without requiring any changes in the cooling
system, make the pulsed electric field technology (PEFT) a strong contender to existing biofouling prevention methods. A recent
field study, where tidal water from the Elizabeth River in Norfolk, VA, was treated by means of the pulsed electric field
method, demonstrated complete prevention of biofouling in pipes when the river water at the intake of the pipes was exposed to
electric field of 6.5 kV/cm with 770 nanosecond pulse duration. The efficiency was 1,400 gallons of treated water per kWh, an
increase in efficiency by more than a factor of three compared to results presented at the 1996 Zebra Mussel Conference.
Experiments with even lower electric fields and correspondingly lower energy consumption are under way. modeling results
indicate that efficiencies of more than 50,00 gallons/ kWh may be reached in fresh water cooling systems.



The livestock fence shocker delivers said pulsed electric field of required intensity. If the electric pulse is monophasic it
delivers net charge into the water, creating electrolysis. If the electric pulse is biphasic (ie: capacitively coupled) it will
deliver no net charge into the water, avoiding electrolysis.

I, know, I know. It's not livestock that are giving your propellor problems and the article only mentions zebra mussels in
1996.

But then you are the guy who wrapped electrical connections in tape for frequently flooded aircraft runways and buried them in
the ground, despite the law saying those connections should be above ground in a hermetic box. How many died because of that?

With barnacle growth the size of a medium shopping trolley fouling your drive train at least you have the electrolysis problem
solved as there are no exposed metals to electrolyze.

I have studied this in depth at university in Bangalore.



Noj

Propeller anti-fouling?
 

On Tue, 19 Jan 2010 07:55:55 -0700, "Noj Zang"
wrote:


"Bruce In Bangkok" wrote in message
.. .

It is not electrolysis I'm fighting, it is shellfish.


Let's try again. The link says:

The application of pulsed electric fields to water containing micro- or
macro-organisms has been proven to be a means of controlling the population
of these organism, or to stun them over a certain electric field dependent
time interval. The fact that the efficiency of this control mechanism
increases with decreasing pulse duration opens the possibility to utilize
microsecond pulse power technology for biofouling prevention in cooling
water systems. The advantages over other techniques used for biofouling
prevention such as its independence from chemicals, the fact that it is
possible to stun, rather than kill unwanted biofouling species, that it does
not generate shock waves which could affect the structure of the cooling
system, and that it can be installed like a filter in front of an existing
cooling system, without requiring any changes in the cooling system, make
the pulsed electric field technology (PEFT) a strong contender to existing
biofouling prevention methods. A recent field study, where tidal water from
the Elizabeth River in Norfolk, VA, was treated by means of the pulsed
electric field method, demonstrated complete prevention of biofouling in
pipes when the river water at the intake of the pipes was exposed to
electric field of 6.5 kV/cm with 770 nanosecond pulse duration. The
efficiency was 1,400 gallons of treated water per kWh, an increase in
efficiency by more than a factor of three compared to results presented at
the 1996 Zebra Mussel Conference. Experiments with even lower electric
fields and correspondingly lower energy consumption are under way. modeling
results indicate that efficiencies of more than 50,00 gallons/ kWh may be
reached in fresh water cooling systems.

The livestock fence shocker delivers said pulsed electric field of required
intensity. If the electric pulse is monophasic it delivers net charge into
the water, creating electrolysis. If the electric pulse is biphasic (ie:
capacitively coupled) it will deliver no net charge into the water, avoiding
electrolysis.

I, know, I know. It's not livestock that are giving your propellor problems
and the article only mentions zebra mussels in 1996.

But then you are the guy who wrapped electrical connections in tape for
frequently flooded aircraft runways and buried them in the ground, despite
the law saying those connections should be above ground in a hermetic box.
How many died because of that?

I suggest that you query the U.S. Air force about regulations applying
to the installation and maintenance of air field lighting systems on
US Military Installations as all work was carried out in accordance
with their specifications. I might also point out that the USAF
maintains a force of inspectors who daily inspect the work
accomplished by contractors so I can only assume that the taped
splices were acceptable to Air Force.

With barnacle growth the size of a medium shopping trolley fouling your
drive train at least you have the electrolysis problem solved as there are
no exposed metals to electrolyze.

I have studied this in depth at university in Bangalore.



Noj


Regarding the electronic barnacle deterrent. Yes, I've seen the web
site on the Internet but what I haven't seen is a yacht with the
system installed. In fact I have never even met an individual who was
thinking about installing the system.

Now, given that every boater who keeps his boat in the water is
interested in shellfish growing/not growing on his hull it pretty much
tells me that either the system doesn't work, or that the system is
not cost effective.

Care to give me a list of boat owners who I can contact to ask them
what they think of the system?

Cheers,

Bruce
(bruceinbangkokatgmaildotcom)

Propeller anti-fouling?
 

On Tue, 19 Jan 2010 10:21:31 -0500, " Tuuk" wrote:

You better announce to the dock master you are putting this type of
electrolisis on your boat.

This could initiate electrolisis and anodic reaction to most other boats
around you and dock and dock hardware and cause them to be the "sacrifical"
part in this corrisive situation.

If you add electrolisis, then all the anodes surrounding your boat will
attract those superfluous emissions and prematurely erode all the anodes.


Also, be careful with painting props for obvious reasons. Half way through
next motoring season when a shaft bearing fails due to introduced
unballanced wear on them, you can be assured that its cause is directly
related to your painting a balanced part therefore making it unbalanced and
causing vibrations and failing bearings or seals. Keep the prop ballanced.


I couldn't agree with you more, however... I'll be willing to bet that
if you pulled the props from every boat in this marina and stuck them
on a balancing machine you'd be lucky to find more then two or two
that were balanced, as they came out of the water, i.e., in the
condition that they are normally used. Stuff grows on propellers all
the time and few if any get every tiny bit off when they dive down and
scrape the propeller.

Cheers,

Bruce
(bruceinbangkokatgmaildotcom)

Propeller anti-fouling?
 

On Sat, 23 Jan 2010 14:07:18 +0100, "Steve Lusardi"
wrote:

Wait a minute guys. I don't think we should just blow this guy off. There is logic to what he says. Although his language is not
clear, I think I understand what Noj is saying. When I first read about this technology, I was also very concerned with
electrolysis, but with after thought, he stated that he capacitively couples the charge. This electrostatic discharge is
effectively AC with negligible polar current draw. If you folks remember there was an episode on the "Mythbusters" where they
tried to corrode through a prison steel barred widow using electrolysis. At the end of the episode, there was negligible induced
corrosion with AC applied, yet a great deal of corrosion was induced with a simple battery. I do not believe this system will
induce a problem. It is certainly worth a test. Bruce, you're on.
Steve

I responded to the guy in a different post but I agree with you that
it is worth exploring and may well be a solution. Some time ago I had
a look at least one web site that advertised a system, as he
describes, as I remember the website used a lot of flash descriptions
and slick descriptions of how it worked... not the sort of explanation
that would encourage anyone who know a bit about electronics. In
addition their prices seemed to be very much the sort of prices one
associated with space capsules.

As I remember one bonded what appeared to be transducers at various
spots throughout the boat and then pulsed them at a fairly low
frequency.

Although it wasn't the site I originally visited, you can get some
details from
http://www.patentstorm.us/patents/5143011/fulltext.html
which is from a patent issued in 1992 so it certainly isn't anything
new.

My comment to the O.P. was that I have never seen or heard of such an
installation on a yacht, nor have I even met an individual who was
interested in looking into the idea. Which maybe just means that
Yachties are dummies.... although I doubt it.

I would really like to talk with someone who had actually tried the
system.

There was also an article entitled "
Go, Navy! U.S. Ships to Try Eco-Safe Anti-Barnacle Tactics
Written by Tina Casey
Published on August 8th, 2009

Which does not mention the electronic method which makes one wonder
about the validity of the claims for the "sound system".

Cheers,

Bruce
(bruceinbangkokatgmaildotcom)

Propeller anti-fouling?
 

On Tue, 19 Jan 2010 17:02:19 -0500, "Flying Pig"
wrote:

Hi, Bruce, et. al.,

It's been in the water too long, now, so it's gone, but PropSpeed lasts a
couple of years. Go to their website for an education, but the simple
process is that it's too slippery for the critters to hold on to and they
sling off.

An etching primer applied to an 80 grit scuffed clean surface first, then
the other stuff on top of it. Basically yellow looking.

My prop stayed clean for the first couple of years in the water. When we
next haul, I'll use it again. Very satisfied.

L8R

Skip

Thanks for the endorsement from someone who has actually used a
product :-)

I believe that International Paints and some of the other paint
companies are also making a product...... I believe a hard
anti-fouling paint, but am not sure.


Cheers,

Bruce
(bruceinbangkokatgmaildotcom)

Propeller anti-fouling?
 

"Bruce In Bangkok" wrote in message
.
snipped
..
Which does not mention the electronic method which makes one wonder
about the validity of the claims for the "sound system".

I seem to recall that this system was based on observations which showed
that the transponders of echo sounders remain free from fouling.

Propeller anti-fouling?
 

On Sun, 24 Jan 2010 14:41:09 +0100, "Edgar"
wrote:


"Bruce In Bangkok" wrote in message
.
snipped
.
Which does not mention the electronic method which makes one wonder
about the validity of the claims for the "sound system".

I seem to recall that this system was based on observations which showed
that the transponders of echo sounders remain free from fouling.

And it may well work, or work in certain instances.

However I think that my point is still valid, that I have never met
anyone who was using the system and if, in fact, the system is
something wonderful it would seem likely that it would be in use.

Cheers,

Bruce
(bruceinbangkokatgmaildotcom)