SailNet Community banner
1 - 20 of 34 Posts

·
Master Mariner
Joined
·
9,187 Posts
Discussion Starter · #1 ·
After finally getting the bottom done in Trinidad, we no longer have volcanoes (barnacles) springing up all over the bottom. However, a slime has developed and I'm a bit curious about it's negative or positive aspects. Most creatures that swim in the sea, have a slimy substance that coats them. I am aware that this is a biological shield and it was common knowledge in catch and release fishing that one should wipe as little off the fish as possible, for their healthy return to the sea. Somewhere in the back of my mind, I seem to remember that this slime also facilitated the fish's movement through the water.
So, my question; do you think we should scrub it off our hard antifouling or leave it? Do you think it will make any difference to our speed either way? It is only slime, not weed or coral.
 

·
Registered
Joined
·
2,709 Posts
I think that any speed gain by getting a smoother surface will be offset by the amount of antifouling that gets removed during the de-sliming process. I've got fresh Islands 66 this year and, for the first time ever, don't even have any slime yet - despite not moving much in St. Martin for weeks at a time. I'll be staying a week in Falmouth, Antigua which will be the real test for this bottom paint as that anchorage is terrible for growth.
 

·
Registered
Joined
·
140 Posts
Did you use Trinidad paint by Pettit or were you in Trinidad when the paint was applied?

Slime seems to cause anti fouling paint to become ineffective and hard growth to form quicker that it would without the slime growing first. Paint companies are constantly working to prevent slime.

I'd scrub the slime off and next time you paint consider using a slime resistant paint like Trinidad SR.
 

·
I don't discuss my member
Joined
·
2,670 Posts
After finally getting the bottom done in Trinidad, we no longer have volcanoes (barnacles) springing up all over the bottom. However, a slime has developed and I'm a bit curious about it's negative or positive aspects. Most creatures that swim in the sea, have a slimy substance that coats them. I am aware that this is a biological shield and it was common knowledge in catch and release fishing that one should wipe as little off the fish as possible, for their healthy return to the sea. Somewhere in the back of my mind, I seem to remember that this slime also facilitated the fish's movement through the water.
So, my question; do you think we should scrub it off our hard antifouling or leave it? Do you think it will make any difference to our speed either way? It is only slime, not weed or coral.

If you think sailing with a dirty bottom is somehow faster than sailing with a clean one, I've got a bridge in Brooklyn to sell you. :rolleyes:

As far as regular cleaning goes, doing it relatively frequently (and therefore gently) will actually help your paint remain effective for a longer time, as opposed to cleaning it less frequently, letting it become more heavily fouled and have to clean it more abrasively. Moreover, using the boat under power with a clean bottom reduces your carbon emissions and fuel consumption.
 

·
Master Mariner
Joined
·
9,187 Posts
Discussion Starter · #5 ·
If you think sailing with a dirty bottom is somehow faster than sailing with a clean one, I've got a bridge in Brooklyn to sell you. :rolleyes:

As far as regular cleaning goes, doing it relatively frequently (and therefore gently) will actually help your paint remain effective for a longer time, as opposed to cleaning it less frequently, letting it become more heavily fouled and have to clean it more abrasively. Moreover, using the boat under power with a clean bottom reduces your carbon emissions and fuel consumption.
Wow, really, I can buy a bridge from you? Gee, thanks.
Our bottom isn't "dirty", it's slimy, and that slime comes off as easily as wiping a hand over it, just like the slime on fish. It is clear and very slippery.
Moreover, since we powered less than 20 hours in the last year of roughly 2500 miles of interisland voyaging, we are not at all interested in a lecture on OUR carbon emissions.
 
  • Like
Reactions: christian.hess

·
Registered
Corsair 24
Joined
·
4,594 Posts
capta in my trips I have only scraped off hard growth and or any algae seaweed stuff mostly on the rudder that would affect steerage...

Im not a fan of scrubbing, ESPECIALLY when cruising...I think the cons are more than any pros in this scenario...

but that is my opinion and those that I know while out cruising before...

scrubbing no matter how you do it removes too much for my likes...
 

·
Master Mariner
Joined
·
9,187 Posts
Discussion Starter · #8 ·
Did you use Trinidad paint by Pettit or were you in Trinidad when the paint was applied?

Slime seems to cause anti fouling paint to become ineffective and hard growth to form quicker that it would without the slime growing first. Paint companies are constantly working to prevent slime.

I'd scrub the slime off and next time you paint consider using a slime resistant paint like Trinidad SR.
I used the paint suggested by the man that paints 500+ boats each year, professionally. I'd think he knows which paints work best in this area, but I will certainly mention your suggestion to him next year.
 

·
Registered
Joined
·
5,071 Posts
A clean bottom will be faster due to the creation of more stable 'boundary layer' flow quite near the surface ... an area of relatively low speed water very close to the hull which as a result, reduces 'friction'.

Second reason for the constant removal of slimes is that 'hard growth' can more easily begin to 'attach' -
1. the slime reduces/lessens the chemical leaching of biocide or metal ions in the coating .... and the new growth is somewhat 'insulated' from this chemical action by the 'massive colony' (calcyx, etc.) of microorganisms, etc. COVERING it ...
2. once hard growth actually begins it will cover (exponentially) more and more surface area of the bottom paint as time goes on thus reducing the anti-fouling activity on an 'area' basis.
 

·
I don't discuss my member
Joined
·
2,670 Posts
...the slime reduces/lessens the chemical leaching of biocide or metal ions in the coating
Almost, but not quite. The biocide leach rate is not reduced, it continues unabated as long as the hull is in the water until the biocide is depleted, regardless of how much growth is on the hull. What actually happens is the slime layer traps the leached biocide between it and the hull, allowing less of the biocide to be available to retard new fouling growth. Keeping the bottom clean helps eliminate this problem.
 

·
Registered
Joined
·
82 Posts
Funny isn't. Divers want you to scrub it and boatyards want you to paint it. This from a boat yard. If it's a slime & not hard growth Imagine this take your boat sailing compare boat speed with the speeds made in the past in the same wind & sea condition. If the boat is going slower than wipe the hull and see if speed changes. Definitely remove any hard growth. Also when you sea marine grass on bottoms and they are flowing in the current that's drag. Drag cost speed.
 

·
Registered
Joined
·
1,341 Posts
Almost, but not quite. The biocide leach rate is not reduced, it continues unabated as long as the hull is in the water until the biocide is depleted, regardless of how much growth is on the hull. What actually happens is the slime layer traps the leached biocide between it and the hull, allowing less of the biocide to be available to retard new fouling growth. Keeping the bottom clean helps eliminate this problem.
Fstbttms... where is the scientific data to back you up on this because what I've read is opposite your statements.

Actually having a thin layer of slime is good for performance and adherence to more fouling!
 

·
Registered
Joined
·
1,341 Posts
Elaborate please.
Other than anti foul paint manufacturers giving you the hype about their products perhaps science indicates an opposite opinion based on observed and measurable data?

You are the one that must produce data to back you up...

Here is one article out of the many including research at MIT and other universities and research facilities.

Hydrodynamic Drag Reduction Due to Fish Slimes - Springer

I have more reading if you care to devote some time to it.


Conclusion:

Data from full ship applications of Foul Release coatings in service shows that the ubiquitous presence of slime fouling appears to off-set the initial reduced drag. However this is not a large effect, and even with this slime present, Foul Release coatings give equivalent speed and fuel performance to TBT SPC antifoulings.
http://www.geocities.ws/maxim_candries/Candries_PCE.pdf

Nature does it best and we should only try to emulate her:

http://www.asknature.org/strategy/0cac943988f8be7d95a63f16ab455609#.UzcaDGJdV9l
 

·
Registered
Corsair 24
Joined
·
4,594 Posts
good job nick...I stopped arguing with people regarding certain every day things boatwise...

basically slime is not in any shape or form bad for any bottom other than looks, I refrain from brushing and or using any method other than a simple scraper...yes some scrapers are better than others but basically you can either pay attention to what paint manufacturers and SALESEMAN want you to do or do what you have learned or gained from experience

Id rather go by what experience and situations dictate me to do and thats that

peace

capta basically just keep barnacles, seaweed or other stuff at bay...slime is ok...

if you let ANY antifouling get REAL bad lile artifical reefs bad lile I had even then it will last a while after scraping...its just not pretty and needs more scraping than new antifouling

I just dont see the whole BAD scenario with slime
 
  • Like
Reactions: Bill-Rangatira

·
I don't discuss my member
Joined
·
2,670 Posts
Fish are not sailboats and the slime they produce is not marine fouling. Apples and oranges.

I'd venture to say that nobody reading this (certainly not the OP) is using foul release coatings, which work completely differently, and are as closely related to traditional copper-based anti fouling paints as a bicycle is to a Ferrari. Further, there is no foul release coating manufacturer that recommends allowing the coating to become covered in slime, because that would make the vessel faster or more efficient and I challenge you to prove me wrong on that point.


This is the best one of all. Your link apparently advocates an anti fouling product that mimicks a fish's slime. The product (Eco-Clad) claims to have been "...created to include nutrients that would attract the right kind of biofilms." So not just any kind of biofilm or slime is desirable to make fish and boats go fast, only ones that hundreds of millions of years of evolution or one really smart chemical company can produce. It is not the same slime that grows on your boat hull between cleanings. If that kind of slime were able to improve a boat's performance, we wouldn't need Eco-Clad, would we? :rolleyes:

But wait! Maybe this engineered slime idea doesn't really work after all-

After further review on the performance of Eco-Clad as a bottom paint, we are NOT offering this product to our customer base. Eco Clad is engineered to support a natural beneficial biofilm (slime) on the coated area. However, we have heard several complaints about the products’ poor performance when it comes to keeping growth off the boat. The company has done a great job of marketing Eco Clad everywhere, and claims better fuel economy and faster speeds. This might be true, but performs only for a few months at best. After that you will see substantial marine growth and even worse fuel ecomony and speed along with the added costs of a new bottom job.

Our opinion and recommendation is to stay away from Eco-Clad unless you plan on keeping your boat in fresh water. Your are much better off using a traditional high quality bottom paint.


Eco-Clad bottom paint review

But here's the bottom line for me- If having a slimed-over hull were faster, more efficient than having a clean hull coated in anything else (or nothing), those boaters that are most concerned with boat speed (sailboat and powerboat racers) would be letting their bottoms get foul with slime. Larry Ellison didn't spend a few hundred million dollars to defend the America's Cup last year without considering what would make his boats move through the water as absolutely fast as possible and his boats never touched the water for more than a few hours at a stretch. If some guy on the SailNet forum could prove that slime is good, don't you think other, smarter, more experienced sailors would have discovered this? They haven't, because clearly letting your hull get dirty is slow and inefficient, not the other way 'round.
 

·
Registered
Joined
·
1,341 Posts
Fish are not sailboats and the slime they produce is not marine fouling. Apples and oranges.
Fish and other marine animals create slime and surface texture to limit drag! It's nature and science whether you care to believe it or not!

Here is America's cup to this answer, this is a rough/smooth skin of shark technology at work:

A key piece of NASA technology assisted in the win. Stars and Stripes design coordinator John Marshall disclosed the boat's "secret weapon" as the hull's underside, coated with a "riblet" skin that helped the craft slide through the sea more smoothly.

NATURE'S VERSION OF A RIBLET
Early in the game of riblet research, Langley found confirmation of grooving's effectiveness in a clue from nature: it was learned that fast swimming sharks have riblet-like projections on their skins. Called dermal denticles, they are made of the same material as shark's teeth and typically have four or five grooves on what appears to the naked eye to be such a smooth surface.
NASA - NASA Riblets for Stars & Stripes



This is the best one of all. Your link apparently advocates an anti fouling product that mimicks a fish's slime. The product (Eco-Clad) claims to have been "...created to include nutrients that would attract the right kind of biofilms." So not just any kind of biofilm or slime is desirable to make fish and boats go fast, only ones that hundreds of millions of years of evolution or one really smart chemical company can produce. It is not the same slime that grows on your boat hull between cleanings. If that kind of slime were able to improve a boat's performance, we wouldn't need Eco-Clad, would we? :rolleyes:

But wait! Maybe this engineered slime idea doesn't really work after all-

After further review on the performance of Eco-Clad as a bottom paint, we are NOT offering this product to our customer base. Eco Clad is engineered to support a natural beneficial biofilm (slime) on the coated area. However, we have heard several complaints about the products’ poor performance when it comes to keeping growth off the boat. The company has done a great job of marketing Eco Clad everywhere, and claims better fuel economy and faster speeds. This might be true, but performs only for a few months at best. After that you will see substantial marine growth and even worse fuel ecomony and speed along with the added costs of a new bottom job.

Our opinion and recommendation is to stay away from Eco-Clad unless you plan on keeping your boat in fresh water. Your are much better off using a traditional high quality bottom paint.


Eco-Clad bottom paint review

But here's the bottom line for me- If having a slimed-over hull were faster, more efficient than having a clean hull coated in anything else (or nothing), those boaters that are most concerned with boat speed (sailboat and powerboat racers) would be letting their bottoms get foul with slime. Larry Ellison didn't spend a few hundred million dollars to defend the America's Cup last year without considering what would make his boats move through the water as absolutely fast as possible and his boats never touched the water for more than a few hours at a stretch. If some guy on the SailNet forum could prove that slime is good, don't you think other, smarter, more experienced sailors would have discovered this? They haven't, because clearly letting your hull get dirty is slow and inefficient, not the other way 'round.
Again you quote a manufacturer to base your opinion because you cannot back up your assertions!

Again I give you America's Cup answer since 'I'm just a guy posting on Sailnet'
all the while you're a guy making money cleaning hull bottoms for a living... what upset that? :rolleyes::rolleyes:

Here is more proof:

Smoother Sailing With A Rough Surface? Ridged Hull Could ?Reduce Drag? And Save Energy On Ships

http://www.pocock.com/wp-content/uploads/2013/08/pocock-floating-on-air.pdf

I have no financial stake in any of this... just don't want people to be fooled by this slime hypocrisy. :laugher :laugher
 

·
Registered
Joined
·
1,446 Posts
Now that is just too hard to take. You wax and launch for each race and some guy with a green slime and blistered hull beats you every time!
Capta, how about a test? Just scrub one side and see what happens. Apparently there authorizes on both side of the issue. When did that ever happen before?
John
 

·
I don't discuss my member
Joined
·
2,670 Posts
Fish and other marine animals create slime ...to limit drag!
Of course they do. I never argued that. The point is the slime fish create is not the same as biofouling found on boats. Not the same, doesn't work the same. Your own link points that out. What is it about that that you don't understand?

Here is America's cup to this answer, this is a rough/smooth skin of shark technology at work:
:confused: What does this have to do with slime?

Again you quote a manufacturer to base your opinion because you cannot back up your assertions!
I didn't quote a manufacturer. I quoted a retailer of the product that you linked to. A retailer so dissastisfied with the engineered slime on boat hulls that they stopped selling the product. The Eco-Clad web site (www.ecoclad.com) also appears to be nonexistant. Not a good sign.

It's my belief that dirty, slimy hulls are slower and less efficient than clean ones and you simply don't have a valid argument proving me wrong.
 
1 - 20 of 34 Posts
Top