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Propeller anti-fouling?
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) |
Propeller anti-fouling?
On Mon, 18 Jan 2010 18:38:26 +0700, Bruce In Bangkok
wrote: 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". Haven't tried it because I don't have a boat. But you made me think that if you knew your boat would be idle a long time, wrapping the prop it in a old piece of poly tarp might work. Maybe even a thick black garbage bag. Should be easier to put that on and crack/cut it away than spend 2 days scraping. Barnacles need some light to grow, right? We sometimes want a patch of lawn for garden and the easiest way to kill the grass is to lay something on it that blocks the light. --Vic |
Propeller anti-fouling?
"Vic Smith" wrote in message ... On Mon, 18 Jan 2010 18:38:26 +0700, Bruce In Bangkok wrote: 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". Haven't tried it because I don't have a boat. But you made me think that if you knew your boat would be idle a long time, wrapping the prop it in a old piece of poly tarp might work. Maybe even a thick black garbage bag. Should be easier to put that on and crack/cut it away than spend 2 days scraping. Barnacles need some light to grow, right? We sometimes want a patch of lawn for garden and the easiest way to kill the grass is to lay something on it that blocks the light. --Vic You're right, that does work Vic. The owner just has to remember to take it off before getting underway! Hope you're well and staying warm. |
Propeller anti-fouling?
"Bruce In Bangkok" wrote in message ... 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) Any paints I've tried get burned off. A friend has gotten his prop plated with copper and swears by it. |
Propeller anti-fouling?
"Bruce In Bangkok" wrote in message ... 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) I'd go with Vic's suggestion for extended periods or areas with warm water like Thailand ;-) Might hang a tag on the engine intake seacock to remind you to remove the covering before getting, or attemping to get, underway. |
Propeller anti-fouling?
Is it possible that there is too much electrolisis loss? And these barnicals
are attracted to that? Using anodes or disconnecting battery or another form of cathodic protection. Have a look at some other boats in the slips to see if theirs has the same problems. If they don't then you may have a electrolisis issue as the prop is the most obvious spot of focus for this as it is the thinest/best part under the water for transfer of electrons. "mmc" wrote in message g.com... "Vic Smith" wrote in message ... On Mon, 18 Jan 2010 18:38:26 +0700, Bruce In Bangkok wrote: 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". Haven't tried it because I don't have a boat. But you made me think that if you knew your boat would be idle a long time, wrapping the prop it in a old piece of poly tarp might work. Maybe even a thick black garbage bag. Should be easier to put that on and crack/cut it away than spend 2 days scraping. Barnacles need some light to grow, right? We sometimes want a patch of lawn for garden and the easiest way to kill the grass is to lay something on it that blocks the light. --Vic You're right, that does work Vic. The owner just has to remember to take it off before getting underway! Hope you're well and staying warm. |
Propeller anti-fouling?
"Bruce In Bangkok" wrote in message .. 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. |
Propeller anti-fouling?
Check the ingredients of that antifoul paint. If its ingredients include
somethings like zinc or cadnium or nickle or magnesium or something with a negative potential, then they are simply trying to solve their anodic galvanic reaction which might be attracting the animals. Easier to solve with a rectifiar or battery issues. "Edgar" wrote in message ... "Bruce In Bangkok" wrote in message .. 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. |
Propeller anti-fouling?
On Jan 18, 10:39*am, " Tuuk" wrote:
Check the ingredients of that antifoul paint. If its ingredients include somethings like zinc or cadnium or nickle or magnesium or something with a negative potential, then they are simply trying to solve their anodic galvanic reaction which might be attracting the animals. Easier to solve with a rectifiar or battery issues. "Edgar" wrote in message ... "Bruce In Bangkok" wrote in message .. 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. I have tried everything and finally decided to use a plastic "Perfectpitch" prop. They provide a special puller so you can easily take the prop off to clean it. |
Propeller anti-fouling?
On Mon, 18 Jan 2010 07:21:16 -0600, Vic Smith
wrote: On Mon, 18 Jan 2010 18:38:26 +0700, Bruce In Bangkok wrote: 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". Haven't tried it because I don't have a boat. But you made me think that if you knew your boat would be idle a long time, wrapping the prop it in a old piece of poly tarp might work. Maybe even a thick black garbage bag. Should be easier to put that on and crack/cut it away than spend 2 days scraping. Barnacles need some light to grow, right? We sometimes want a patch of lawn for garden and the easiest way to kill the grass is to lay something on it that blocks the light. --Vic Yes, putting a black garbage bag over the prop does cut down on growth drastically... however. As it was really happenstance that the boat wasn't taken out so no plans had been made for storing the boat and secondly, most people start the engine every week or so even if the boat is not being used. Inadvertently most of those who have taken the precaution to bag the prop seem to test the transmission when running the engine which sort of negates the whole project. (the bag rips). Cheers, Bruce (bruceinbangkokatgmaildotcom) |
Propeller anti-fouling?
On Mon, 18 Jan 2010 09:55:14 -0500, " Tuuk" wrote:
Is it possible that there is too much electrolisis loss? And these barnicals are attracted to that? Using anodes or disconnecting battery or another form of cathodic protection. Have a look at some other boats in the slips to see if theirs has the same problems. If they don't then you may have a electrolisis issue as the prop is the most obvious spot of focus for this as it is the thinest/best part under the water for transfer of electrons. Cathodic protection is exactly the same as it has been for the past 15 years or so. The propeller and shaft are insulated from the rest of the boat and an anode is placed between the prop and the stern bearing. "mmc" wrote in message ng.com... "Vic Smith" wrote in message ... On Mon, 18 Jan 2010 18:38:26 +0700, Bruce In Bangkok wrote: 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". Haven't tried it because I don't have a boat. But you made me think that if you knew your boat would be idle a long time, wrapping the prop it in a old piece of poly tarp might work. Maybe even a thick black garbage bag. Should be easier to put that on and crack/cut it away than spend 2 days scraping. Barnacles need some light to grow, right? We sometimes want a patch of lawn for garden and the easiest way to kill the grass is to lay something on it that blocks the light. --Vic You're right, that does work Vic. The owner just has to remember to take it off before getting underway! Hope you're well and staying warm. Cheers, Bruce (bruceinbangkokatgmaildotcom) |
Propeller anti-fouling?
On Mon, 18 Jan 2010 09:48:00 -0500, "mmc" wrote:
"Bruce In Bangkok" wrote in message .. . 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) Any paints I've tried get burned off. A friend has gotten his prop plated with copper and swears by it. Interesting. There is a plating shop near here that might be able to do that. I shall ask. Cheers, Bruce (bruceinbangkokatgmaildotcom) |
Propeller anti-fouling?
On Mon, 18 Jan 2010 09:51:00 -0500, "mmc" wrote:
"Bruce In Bangkok" wrote in message .. . 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) I'd go with Vic's suggestion for extended periods or areas with warm water like Thailand ;-) Might hang a tag on the engine intake seacock to remind you to remove the covering before getting, or attemping to get, underway. Been there, done that and it works a treat if you are going to leave the boat for some time. In this case I was living on the boat and working on a second boat. The enthusiasm for finishing the second boat precluded sailing the first boat. Cheers, Bruce (bruceinbangkokatgmaildotcom) |
Propeller anti-fouling?
On Mon, 18 Jan 2010 10:39:05 -0500, " Tuuk" wrote:
Check the ingredients of that antifoul paint. If its ingredients include somethings like zinc or cadnium or nickle or magnesium or something with a negative potential, then they are simply trying to solve their anodic galvanic reaction which might be attracting the animals. Easier to solve with a rectifiar or battery issues. No exotic additives. From all I can find out the paint is basically a very hard anti-fouling applied over some sort of (perhaps) epoxy based primer. The one magazine article I read stated that the paint lasted an entire season on a trawler yacht but I'd really like to see it in action before spending the money. Cheers, Bruce (bruceinbangkokatgmaildotcom) |
Propeller anti-fouling?
On Mon, 18 Jan 2010 16:28:05 +0100, "Edgar"
wrote: "Bruce In Bangkok" wrote in message .. 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) |
Propeller anti-fouling?
This works well:
http://www.sgnis.org/publicat/ab97_43.htm Connect a bi-phasic livestock fence shocker to your propeller shaft and you will experience no electrolysis. Noj |
Propeller anti-fouling?
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 . . 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. |
Propeller anti-fouling?
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Propeller anti-fouling?
On Mon, 18 Jan 2010 21:18:39 -0700, "Noj Zang"
wrote: This works well: http://www.sgnis.org/publicat/ab97_43.htm Connect a bi-phasic livestock fence shocker to your propeller shaft and you will experience no electrolysis. Noj It is not electrolysis I'm fighting, it is shellfish. Cheers, Bruce (bruceinbangkokatgmaildotcom) |
Propeller anti-fouling?
"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?
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?
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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) |
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. Transducers convert electricity to sound, in this case. Which is what your meant. Transponders pick up an signal and send out a reply. They have them in comsats. IFF uses transponders. Casady |
Propeller anti-fouling?
On Mon, 18 Jan 2010 07:21:16 -0600, Vic Smith
wrote: On Mon, 18 Jan 2010 18:38:26 +0700, Bruce In Bangkok wrote: 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". Haven't tried it because I don't have a boat. But you made me think that if you knew your boat would be idle a long time, wrapping the prop it in a old piece of poly tarp might work. Maybe even a thick black garbage bag. Should be easier to put that on and crack/cut it away than spend 2 days scraping. Barnacles need some light to grow, right? We sometimes want a patch of lawn for garden and the easiest way to kill the grass is to lay something on it that blocks the light. Barnacles are animals, not green plants, and they don't need light. They need food and oxygen and the bag would cut off both. |
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