Ultrasonic antifouling - any comments

They have been in Australia for years. One of the local yachts here has a unit, the one you see advertised in the local mags except he bought his from England. He saved about a thousand dollars. He is a local plumber with a nice looking Jarkan 31 with a saildrive and folding prop. He was a bit disappointed to find the transducer unit was housed in a stock plumbing unit and the control box is just a stock electrical junction box. Jewellers use sonic cleaning tanks to clean customers jewellery I would check the power consumption of these units and see how close they are to 0.6 amps. I had a look when he slipped last and there may have been a slight reduction in crap for a couple of feet around the folding prop.

In my previous career I spent 14 years of my 20 in the navy as aircrew operating airborne electronics, radar and sonar. Prior to that I was a sonar operator so I have a fair idea. Mate of mine still works for the navy in the aircraft electronics maintenance side. He has a boat on a mooring here as well and I asked him why he had not built a unit for himself. He said that to be effective it would be power hungry and require dozens of transducers.
Then of course how would it effect the rest of the marine life?

PB boating magazine carried out a comparison test a few months ago which sparked a bit of debate on their forums. Did not answer any questions for me.

G'day Roger,
Its unlikely that these were 12v units. They may have been 12v when the voltage reached the water from a step down unit supplying 240v or even 415v. The units we are discussing only have a current draw of a fraction of an amp and are a constant drain on the house battery for yachts on moorings. The "ultrasonic" energy transmitted through the hull into the water is minute.

Do the piles at Kwinana all have ultrasonic units now?

We had a yacht in our marina, trialing this system for about a year.
He had a representative from the company visit a few times.
Its no longer on the boat.
Make your own assumptions from this situation.
I personally think it might be like those things a famous racing car
driver brought out to save fuel.... I dont see them anymore either.
IMO.

They are a bit like the bracelet thingis that have a hologram on to harness the bodies natural frequency.
Maybe there is something to it as I have seen people use the hologram effect of a CD strung along a boat in an attempt to reduce biofouling from seabirds.

But the sonic antifoul device is a total crock.

One of my jobs in WA in the 70s was replacing sacrificial anodes on the jetty piles. Some of these were connected to 12v DC at a very low rate, and the marine weed growth on these piles was almost zero compared with anodes that were not powered. There were no mussels or barnacles present either, yet, the unpowered piles adjacent
were covered in mussels. I pressume that this would work on a boat hull or pontoons with a similar effect. Maybe could be run from a solar panel or small wind generator???
RogerG

FRANT
Can' help what you think! Or don't think!~! I know what I worked on and what Western Mining paid me for. How would you know what systems presently exist or have existed? As I posted earlier, there were several experiments going on when you were still a child! One such was the "Elinca" system which has been steadily evolving for the past 60 years and is still being used today. It consists of an Aluminium anode and a copper anode which are fed with a low voltage DC current and usually using the pylon or vessel body as the cathode but anything that is handy could be used as the cathode. This system and similar are used on many oil rigs and jetty systems throughout the world.
If you have any constructive comments then I would welcome them but please keep you negatives to yourself or share them with the likes of Tony Abbott and stop being so rude.
Rogerg

This mob even offer "IF IN 120 DAYS OF USE THERE IS ANY BARNACLE GROWTH WILL GIVE YOU YOUR MONEY BACK"
http://www.globalmarinegroup.com.au/2b-sure

Or this one
www.hotfrog.com.au/Companies/A1-Marine-Matters/2-B-Sure-Antifouling-System-94219

On second thoughts don't bother because FRANT reckons that 12volt/solar ones don't exist.
Cheers
RogerG

Unless there is a physical coupling between dissimilar metals, galvanic action should not take place. The power used is only very low compare with ICCP systems which Frant was going on about. There is only just enough current to disperse the copper ions around the outside of the hull. Marine life does not like this environment so does not "Stick around" It would be likely that the Steber34 had been freshly anti-fouled and that your boat was copping lumps of copper salts that were sloughing off and making physical contact with the Star's hull thus creating a galvanic action. These units would disperse around 2 parts per billion which would discourage marine species
at slack water intervals but would be ineffective under rougher conditions when it would not be needed anyway.
There have been a few variations on this theme over the years and I am trying to find out if our South African friends have come up with anything. I know that they make good shark repellers, I used one for years.
RogerG

Frant
As for being RUDE remember that YOU started it and I alway give as good as I get!
As for your "Expertise" You seem to have a fixation with ICCP high potential applications when I am clearly talking about MGPS low potential applications If you are the expert that you claim to be then there would not be this confusionin your mind.
The applications that I worked on in 1974-76 were NOTHING to do with anti-corrosion
and the jetty piles used as controls and experiment were used because of their limited access to the public. YOUR factory did not supply anything to us! If indeed you had your own factory at age 18 as well as a degree in engineering. If so, good luck to you!
Before you question my credibility further I suggest that you study the subject and find out exactly what it is that you are talking about. After all,you stated that 12v DC systems don't exist when they clearly do.
RogerG

By the way Roger do you have a commercial affiliation with these antifouling products? Its just that I noticed that the FAQ information has some technical mistakes that could be corrected so that the answers are a little more convincing. If you have an association then I would be happy to pass on this information.

My apologies Roger but to suggest that I am on something is again rude on your part. I have reread my posts and I am struggling to find where I have misquoted you. Is it indeed possible to misquote somebody by "quoting" them verbatum? But you have certainly made claims that I have said things that I have not said. If you disagree could you please enlighten me as to exactly where I have misquoted you and where I have said the things you attribute to me? And I am definately not questioning your credibility...that is yet to be established.

Roger Seems that you edited your post after I quoted it. You in an earlier post said "One of my jobs in WA in the 70s was replacing sacrificial anodes on the jetty piles." Sorry but sacrificial anodes are solely the domain of a corrosion protection system. It was this statement that introduced the element of "anti-corrosion" to the discussion. You did not mention anything about anti fouling devices or experiments which did not involve the sacrificial anode system. And I reiterate "There is no correctly installed sacrificial system anywhere that has 12V DC connected at a very low rate." The devices you refer to are not a sacrificial system. Indeed I did refer to the existence of commercial anti fouling systems for sea chest and pipework applications. The systems that you have brought up are not to my knowledge widely used in commercial applications and IMO would raise concerns about the increased risk of stray current corrosion. I have not commented on the efficacy of these systems from a fouling perspective, I would simply warn of the dangers of causing corrosion...and that is my area of expertise.

WRONG AGAIN!!!!!!!!
I did not edit anything after you quoted it!
Nowhere did I mention that I connected anything to anything.
Nowhere did I mention anything about variable voltage power supplies!
Nowhere did I mention anti-corrosion in my work. This was your arrogant assumtion.
This topic was on anti_fouling. You introduced the anti-corrosion aspect because this is all that your limited mind can conceive!

You just don't get it do you? Read the description of the item refered to in the links that I left. The anodes require replacing periodically because they are sacrificial. They get used up!!!!
The anodes that I worked on were part of an ongoing experiment. They were nothing to do with anti-corrosion. This is your assumption.
You got it wrong from the start. Just because somebody mentions something that you are totaly ignorant about does not mean that it does not exist
As for being rude. Enjoy your Coopers Pale homebrew that you are not on.
By the way, did you manage to get all the labels off?
RogerG

It happened only in your warped mind! I noticed that you could not spell "again" in your last post or was it spot the deliberate mistake?
I joined this forum to offer my positive input to anybody interested. However you alway get negatively minded moron lurking to offer his small minded abuse. This will be my last post to this site due to one idiot!
RogerG