Bottom cleaning without rubbing away anti-foul

[simonpickard]

Hello all,

We got our bottom cleaned and added new anti-foul a few months back.
After some long passages we've got a bit of the dreaded green slime glowing in places which we need to clean off.

Was just wondering if anyone has any tips of how to get this off without damaging the new anti-foul?

After everything I've tired my bear hand seems to be the best method.

Any ideas?

Regards,
Simon

[roverhi]

If you have a hard bottom paint, scrub away! The biocide leaches out through the paint. The paint is so hard that any amount of scrubbing will have virtually no effect on its anti fouling properties.

Ablative paints, on the other hand, work by sloughing off along with any growth and constantly exposing fresh anti fouling. Otherwise. You want the paint to be abraided away to a certain extent. The key is not getting too aggressive with the scrubbing. Use a soft brush or cloth to clean the junk off. Stay away from the course abrasive pads like green and black ScotchBrite until the paint is gone and you really need it. Judicious use of a putty knife to get barnacles off may also be necessary if you are in area especially afflicted with the buggers. The key is to use the gentlest technique and tools that will get the job done. Just don't expect to see a red cloud as you clean the hull.

[MarkJ]

With new ablative paint I would not touch it. The green slime wont slow you down and will come off as the paint ablates.
Any barnicles are a different matter and if you get to them early the are not stufpck on hard and you can scrap them off by hitting their shells not the paint.

Your thoughts of your bare hand is good, except if theres a barnicle there, it'll slash your hand.

Other tip someone gave me was to give a very gently wipe (not a rub!) a day or tow before the full moon because many critters spawn on the full moon. I dont know how right this is.


Mark

[BandB]

Originally Posted by simonpickard

Hello all,

We got our bottom cleaned and added new anti-foul a few months back.
After some long passages we've got a bit of the dreaded green slime glowing in places which we need to clean off.

Was just wondering if anyone has any tips of how to get this off without damaging the new anti-foul?

After everything I've tired my bear hand seems to be the best method.

Any ideas?

Regards,
Simon

Follow the instructions of the paint used. Go to their website and they'll have very detailed and specific instructions, but these do vary with different anti-foul paints, even within hard or ablative groupings. If for some reason, the company doesn't have that information easily available then I'd email them with my specifics.

[Hud3]

I put an old sport sock over my hand and lightly rubbed the slime off. Very little of the ablative paint was disturbed.

[fstbttms]

Here's the trick- always clean your paint (be it hard, ablative or otherwise) before it gets even moderately foul so that it can be easily cleaned with the softest media possible. For professional hull cleaners, this is typically a piece of carpet or a white 3m Doodlebug pad. Don't listen to advice telling you to wail away at hard paint. It can be removed very easily with agressive scrubbing. Frequent gentle cleaning will dramatically extend the life of your anti fouling paint, as opposed to less frequent, more abrasive cleanings.

Check this out:

https://www.youtube.com/watch?v=qzawnxVPlL0

https://www.youtube.com/watch?v=kgPmXg1-o5g

[deblen]

A common garden pump sprayer filled with bleach/water mix(Clorox/Javex) will kill existing growth with no harm to paint or gelcoat.
It will not remove it,but the dead remains will slough off easier & will have less drag(shrivels it).Wear gloves & old clothes.
Or a weeks trip in fresh water river.

[finding41]

fstbttms has it. (Great videos by the way!)
I take my boats (All with ablative paint.) into shallow water and give a scrub with my soft car washing brush. It has an extendable handle and long soft bristles so I don't scratch at the paint. As I walk around and scrub I only ever see the green of the slime and grass in the water.
I pull my boats at the end of each season. (Canada...) When I do that I power wash them gently. Gently with the fan shape spray. I also use the same car wash brush for any stubborn spots.
It works well for me allowing me to get at least 3 seasons out of an ablative coating. (It may last longer but I've only done that for 3 seasons so far.)
I use AquaGuard acrylic. Use what everyone in your sailing area suggests.

[thinwater]

I started using Berber carpet squares based upon Fastbottoms comments. Held with rubber-faced gardening gloves they make fast work with minimal paint removal. Last several seasons too.

I also carry a plastic scraper (mostly used for cleaning the anchor when it comes up--won't scratch galv) just in case there is a spot of hard growth (for example if the bottom of the keel was missed). But ONLY for a few spots. The wooden handle makes it float.

[rwidman]

Originally Posted by deblen

A common garden pump sprayer filled with bleach/water mix(Clorox/Javex) will kill existing growth with no harm to paint or gelcoat.
It will not remove it,but the dead remains will slough off easier & will have less drag(shrivels it).Wear gloves & old clothes.
Or a weeks trip in fresh water river.

It seems to me that would be hard to do without hauling the boat out of the water.

[deblen]

Originally Posted by rwidman

It seems to me that would be hard to do without hauling the boat out of the water.

Yes-it would be.

[StuM]

Originally Posted by rwidman

It seems to me that would be hard to do without hauling the boat out of the water.

Just beach it for a few hours on a sand bank when the tides are right.
(Of course, it's easier with two hulls )

[David B]

For the future, I suggest you have a look at Coppercoat. It's a rock-hard two-pack epoxy resin with 2kgs of copper powder per litre in it. Generally works at least as well as antifouling paints, but the difference is when you do scrub it, you are only removing fouling. Typically lasts 10 years before needing a recoat. We have it on two yachts and would not consider anything else at this stage.

[fstbttms]

Originally Posted by David B

For the future, I suggest you have a look at Coppercoat. It's a rock-hard two-pack epoxy resin with 2kgs of copper powder per litre in it. Generally works at least as well as antifouling paints, but the difference is when you do scrub it, you are only removing fouling. Typically lasts 10 years before needing a recoat. We have it on two yachts and would not consider anything else at this stage.

As a hull cleaner, I have a different opinion of that product.

[David B]

Doesn't look like genuine Coppercoat to me. There are a few such products out there, but the Coppercoat one is the original, is used by a large number of major boat builders, and is Lloyds certified. The genuine article looks basically like brown copper after it is cured. After being hauled from the Med in 2013, there was nothing on our hull, other than a single barnacle up inside the water inlet for the engine. On the actual hull, it appeared clean - no furring, no weed, nothing. But then when I wiped my hand over it, there was just a slight yellow stain on my hand.
We will be back next month after a years absence, with our yacht just sitting in a nutrient-rich marina berth going nowhere over that time. I will be as interested as anyone to see what the hull looks like then. I am expecting to just take her out into the bay for a quick scrub, but we will see. If the sail-drive needs a re-coat of hard antifoul, then we will have to get her hauled and pressure-washed (much easier to replace the anodes anyway). If I think of it when over there, I will report back mid to late May.