Ultrasonic Antifouling Info

[Cheechako]

Originally Posted by David M

I am left wondering if it is so successful then why is it not in common use?

Based on the recent posts regarding how ineffective bottom paint is, I guess electronic systems ARE just as sucessful! BTW: I have a device I sell cheap that keeps elephants away.... I can prove it works because I use it and there are NO elephants in my yard!

[Aussiesuede]

Originally Posted by David M

I am left wondering if it is so successful then why is it not in common use?

The "solar" effect perhaps? Most homeowners know that installing solar panels will save them money on electricity over time, yet few are willing to entertain the initial installation expense, even though the panels will definitely pay for themselves in energy savings. People are creatures of habit and change doesn't always come easy.

The rotary engine, with it's fewer moving parts, is a more efficient powerplant - yet the 100 year old piston engine still prevails.

[fstbttms]

Originally Posted by realem

PS
My boat is in the water 24/7 12 months a year. It is florida water and it is warm and growth usually starts immediately. My units draw 400 miliamps and I leave it on all the time. No battery issues at all. Even my knot meter works now

Mike

Other than owning the product, are you affiliated with the manufacturer in any way?

[fstbttms]

Originally Posted by bluetriguy

...epoxy/copper was slimy only

So what's on your boat now?

Originally Posted by bluetriguy

(this copper treatment may be becoming illegal in Calif soon)

Not even remotely true.

[fstbttms]

Originally Posted by David M

I am left wondering if it is so successful then why is it not in common use?

Forget common use, if any of these things worked (cayenne pepper, copper powder simply mixed into epoxy or ultrasonic devices) major manufacturers would be selling them. You'd find Pettit Pepperpoxy paint on the shelf at West Marine. You'd see bottles of copper powder being sold by West Systems to go along with their epoxy. Walmart would have ultrasonic anti fouling kits in their boating department. But you don't find any of this. Why? Because they don't work.

[bobconnie]

Gee fastbot how do you know this for sure ?? have you tested this type of stuff ?? I haven't! but it sounds like some others have ! I guess it's alright to state an thought, but it sounds a little like sour grapes for ya to be so sure of something you have not personaly tested ! I know your in the bizz and have a lot more of an idea about what works for bottom paint in your area but, I think that maybe some of these folks Might just be telling the Truth !! Just my 2 cents !!

[fstbttms]

Originally Posted by bobconnie

Gee fastbot how do you know this for sure ?? have you tested this type of stuff ?? I haven't! but it sounds like some others have ! I guess it's alright to state an thought, but it sounds a little like sour grapes for ya to be so sure of something you have not personaly tested ! I know your in the bizz and have a lot more of an idea about what works for bottom paint in your area but, I think that maybe some of these folks Might just be telling the Truth !! Just my 2 cents !!

Not sour grapes. Just amazement that every time somebody comes into this forum touting the anti fouling magic bullet that they possess (but amazingly, nobody else seems to), a certain percentage of the users here are all ready to believe any wild claim anybody makes. Yes, I am in the biz. And I don't have to test each magic bullet myself. It's already been done! None of these things is new. Every single one of them has been around for decades. Boat owners are clearly very interested in improving on current anti fouling paint technology and if there was a better mouse trap to be had, it would be on the market, making money. The fact that not a single one of these ideas has gotten even the least bit of traction in the recreational boating industry is proof enough for me that they don't work.

But feel free to spend your 2 cents on snake oil. Be sure to let us know how that works out for you.

[stillbuilding]

Well with a big steel boat soon to be launched I am prepared to do a trial on steel panels in a commercial harbour in Hong Kong. I would welcome input on the trial design. Ie paint type, panel size, duration etc.

Anyone want to contribute ideas to this trial? And maybe a volunteer to do a comparison study in the US and elsewhere?

Let us do one good trial before i have to waste money on my boat antifouling.

Might be an interesting thread.

[fstbttms]

My concern would be the possibility that part of what makes an ultrasonic device (allegedly) work is hull shape and that testing on free-hanging panels might not give an accurate result.

[noelex 77]

There are some promising reports on the effectiveness of ultrasonic antifouling.
While back in Australia I purchased a jaycar ultrasonic antifouling kit. Only $250 for a single transducer. I figure at that price it's worth a try particularly as I would consider it worthwhile if it only extended the time between haul outs.
A single transducer is not enough for my boat so I intend to mount it near one end of the boat and if I notice a difference I can fit another transducer

[Katiusha]

Originally Posted by noelex 77

A single transducer is not enough for my boat so I intend to mount it near one end of the boat and if I notice a difference I can fit another transducer

If you do that, note that the guys from various ultrasonic companies at the boat shows suggested to start with a clean[ed] hull, prop, etc as it's harder [and impossible for large barnacles] to break the bond of critters with the hull than preventing it from happening in the first place.

... i.e. it's not a hull cleaning device, but a preventing new growth device. And if there is a bunch of growth on the hull already, it would dampen the effect [sometimes completely].

[noelex 77]

Originally Posted by Katiusha

If you do that, note that the guys from various ultrasonic companies at the boat shows suggested to start with a clean[ed] hull, ].

Thanks for the tip.
I think it may be a few months before I get around to building and fitting it, but I will give the whole hull a good clean as a starting point.

[pwhitburn]

I have fitted 2 of the units that you buy in kit form from Jayco in Australia. One has been operating for about 12 months installed over the prop (40 ft fibreglass yacht) and I built and installed the other forward of the keel about 6 months ago. Initially I was impressed and there is no doubt that 16 months after the last anti foul that the bottom is cleaner than before installation. However it does not keep the bottom clean and I still get some growth. Either the barnacles wear earmuffs in Sydney or the Jayco units are sub standard or they just don't do as advertised. I am not going to give up yet and will try them for another 12 months after the next anti fouling but I would think carefully before investing a lot on this system. The Jayco units were only $250.00 each so its not a big deal but if I had spent $2k + on units I would not be impressed.

[Hirum]

SAIL mag. did a test Testing Ultrasonic Antifouling | Sail Magazine
Anyone aware of any other independent testing?

[Singleprop]

Here is a study extract, not exactly sure what the verdict is:
""
Inhibition of barnacle cyprid settlement using low frequency and intensity ultrasound.
Guo S, Lee HP, Teo SL, Khoo BC.
Source
Department of Mechanical Engineering, National University of Singapore, Singapore, 117576. gsf830@hotmail.com
Abstract
Low frequency, low intensity ultrasound was demonstrated as an effective inhibitor of barnacle cyprid settlement. When the same substratum vibration amplitude (10.05 nm) and acoustic pressure (5 kPa) were applied, ultrasound at a frequency of 23 kHz significantly reduced cyprid settlement. The mechanism appeared to differ from the ultrasonic cavitation induced inhibition previously reported as no increased mortality was observed, and no change in the exploratory behaviour of cyprids was observed when they were exposed to this continuous ultrasonic irradiation regime. The application of ultrasound treatment in an intermittent mode of '5 min on and 20 min off' at 20-25 kHz and at the low intensity of 5 kPa produced the same effect as the continuous application of 23 kHz. This energy efficient approach to the use of low frequency, low intensity ultrasound may present a promising and efficient strategy regarding irradiation treatment for antifouling applications.
PMID: 22296259 [PubMed - indexed for MEDLINE]
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