Water blasting barnacles below waterline while diving?

[LeoKa]

I do my hull cleaning with a hookah setup. It is not bad, but I get tired fast. Scraping by hand and trying to stay close to the hull, really eats up my energy. The boat is 50+ so plenty of surface down there. Normally takes me 5-6 hours to clean.
I know high pressured water can cut metal, etc. Is there a setup, or system, where one would have a compressor, a long enough hp hose, and an adjustable spray gun, to knock the barnacles off underwater? Of course, the pressure should not be too high, so the paint could stay on. The stores sell hp water compressors, but they might not be strong enough underwater, plus they come with long wand. A shorter spray gun would be easier to work with. Things can get tangled easily when you float around the hull.
The shape of my hull is not easy to work with, the rudder and keel have lots of hard to get spots, and the weed is not easy to scrape off.
We can all do a lift out and pressure wash the hull at a yard, but it is not economical on a monthly bases. In our area, barnacles grow back on happily in a month. I hate them, but that is not enough to get rid of them. Lol.
And yes, I did contact dive companies in my area, but they are not eager to work on my boat. Could it be the large, not easy curved shape, or the time it takes? I don’t know. I am stuck with this problem and I try to make it a bit easier. I plan to pull out the boat and do a proper paint job on the hull next summer, but until then, I need dive 2-3 times every month to keep the hull in shape.
All suggestions are welcome.

 

[O C Diver]

I have seen a pressure washer used in a video for underwater hull cleaning, but don't believe it was used on barnacles of any size. It was quite quick and effective.

If you choose to try one on your hull, I would plan to do it more frequently to eliminate the need to tackle larger barnacles.

A Google search might help you find the video.

Ted

 

[DavidM]

I suppose you are talking about an underwater power wash system, similar to such systems that are used on land to knock bottom growth of while the boat is hanging in a sling. You can buy a light duty power wash system at Home Depot, etc.

The problem you will face is that the water velocity drops rapidly underwater as soon as it leaves the nozzle even within a few inches. Maybe if you developed a sort of fan wand that would rub along the bottom and keep the spray pattern at a fixed distance from the hull as you remove bottom growth. You will have to adjust the spray pattern (wide vs narrow) and the distance from the hull to remove the bottom growth but not remove paint.

Amazon is amazing. Here is a 15" disc surface washer that might work- https://www.amazon.com/Briggs-Strat...d1c8c-2fd2-4f19-aa41-2df022bcb241-spons&psc=1

It connects to your power washer hose and has rotating nozzles that remove surface debris. Whether it will work underwater is a question. I suspect not as the rotating nozzles will be significantly slowed by underwater resistance. But who knows?

Here is another device, more in tune with my original thoughts. See- https://www.amazon.com/ZALALOVA-Pre...sprefix=underwater+power+wash,aps,1568&sr=8-8

It is a rolling carriage that holds 4 nozzles that are set at a fixed distance from the rolling surface. You might get this to work maybe by adding more nozzles and extending them closer to the surface so you won't lose too much water velocity.

David

 

[RT Firefly]

Greetings,
Mr. L. I would certainly try a pressure washer and I'm sure you can get a cheap wand that can be adapted to a short profile. The ONE concern I would have is reverse thrust. Exit of water under pressure will want to push you in the opposite direction unless you can anchor yourself, somehow (stand on the seabed?, grab rope?, waterproof skyhook?).

 

[LeoKa]

I have seen a pressure washer used in a video for underwater hull cleaning, but don't believe it was used on barnacles of any size. It was quite quick and effective.

If you choose to try one on your hull, I would plan to do it more frequently to eliminate the need to tackle larger barnacles.

A Google search might help you find the video.

Ted

I’ll search for the video.

I am already going down once a month, which is way more than I want to. Lol

 

[kchace]

I'll second RT's comment. If you're having trouble staying near the hull now, think of the thrust of a pressure washer pushing you away much more than hand pressure. You'd need a plan (something to hang on to?) to counteract that thrust.



Ken

 

[LeoKa]

Greetings,
Mr. L. I would certainly try a pressure washer and I'm sure you can get a cheap wand that can be adapted to a short profile. The ONE concern I would have is reverse thrust. Exit of water under pressure will want to push you in the opposite direction unless you can anchor yourself, somehow (stand on the seabed?, grab rope?, waterproof skyhook?).

I am using several ropes along the hull already. I’ve positioned them at different level and they help me tremendously. I rarely have to use the fins.

Yes, the wand has to be short. I am not sure if I want to build additional attachments. Simpler the better. Again, things get tangled down there. The hp wand might not work perfectly all the time, but would certainly help to get into little corners.

 

[LeoKa]

It is a rolling carriage that holds 4 nozzles that are set at a fixed distance from the rolling surface. You might get this to work maybe by adding more nozzles and extending them closer to the surface so you won't lose too much water velocity.

David

David

Your recommendations are valid, but the less things I need to carry with down there the better. The water pressure idea is just to assist me somewhat. I still need to use my scrappers for larger animals, but the surface is huge and with the spray I could move along faster. You’d be surprised how much the scrapping takes out of me. The constant moving of arm back and forth against the water is not easy after a while. I carry 4 different scrappers with me. I need to switch hands regularly to give some rest to a working arm.
With a nozzle, this could be eliminated or significantly reduced.
I do have a hp washer already. I just need to buy a longer hose and a short wand to test this idea out.

 

[Stabi]

Get a good toilet plunger, cut the handle down, attach a wrist loop, and when it is attached to the hull, you will be anchored / have a hand hold, to that spot. You can usually slide it along the hull as opposed to pulling it off and reattaching it. If you put a 45 ( plumbing PVC fitting) on the cut down handle, it will be easier to hold on.

 

[Stabi]

Or one of these,
https://remoramarine.com/remora-solo/

 

[LeoKa]

Or one of these,

https://remoramarine.com/remora-solo/

Looks pretty cool. Pricey, too. Might work perfectly on a nice even surface. My biggest challenge is the uneven surface, like my rudder and keel. This would not work there. I have cordless brush already, but it is only good for the areas close to the waterline.

 

[Keysdisease]

I've done it with a regular 3500 PSI gas powered pressure washer. You need to get right near the hull with the nozzle, and I could only clear like a 4"-5" swath with each pass. I anchored the boat fore and aft on sand in the right depth so I could get my feet into the bottom to help stay in place. Slow going but clean when done, great for the prop as scraping it's a real PITA

 

[LeoKa]

I've done it with a regular 3500 PSI gas powered pressure washer. You need to get right near the hull with the nozzle, and I could only clear like a 4"-5" swath with each pass. I anchored the boat fore and aft on sand in the right depth so I could get my feet into the bottom to help stay in place. Slow going but clean when done, great for the prop as scraping it's a real PITA

Nice to hear from your experience. It seems it was not a crazy idea after all. It is ok that only a narrow swath gets done, as long it goes ahead.
Having a good spot for standing would be nice, but the tide here is tricky. Sometimes 15-20 feet up and down.

 

[LeoKa]

High-Pressure Plastic Body Wash Gun, 5 gpm

https://www.mcmaster.com/3364K71

High-Pressure Spray Nozzle, 1/4 NPT Male, 5 gpm @ 1000 PSI, Flat Spray

https://www.mcmaster.com/3234K92

Pressure Washers, Buna-N Rubber, 1/4 x 1/4 NPT Fittings, 1/4" ID, 5/8" OD

https://www.mcmaster.com/53115K26


What do you think about this combination? Not cheap, but looks like a solid setup.

 

[Northern Spy]

What really matters is the angle of attack and nozzle pattern.

Spraying systems (spray.com) is a resource I used in industry that may give you some ideas.

 

[Solly]

Just throwing this out there.
How about something air powered ?? Sander, scraper ?? Maybe use a scotch brite pad instead of sandpaper. Right angle grinder.
No idea what might be available...

It would eliminate the reverse thrust. I'd think you would spend as much energy holding on as scrapping...

 

[Keysdisease]

5 gpm @ 1000 PSI, Flat Spray.

1000 psi won't do it. Take a trip to your local Boatyard and see what psi machine they use, betting its at least 3500, which is what i used.

They can be rented, maybe buy your own hose/wand and nozzles to use with a rental.

 

[backinblue]

I’ll search for the video.

I am already going down once a month, which is way more than I want to. Lol

"That's what she said" - Michael Scott

 

[Larry M]

One dive company that cleans boat bottoms in our marina use a gas powered pressure washier for props, rudders and shafts. It’s a better and quicker job than doing it manually. It is a little unsettling when your inside and hear the underwater noise though. They still scrape the bottoms.

 

[Bmarler]

What are you using for bottom paint? I’m in Puget sound too, and I don’t have trouble with barnacles like you seem to be having. Sure, the prop and shaft get them but not the hull. A good bottom job should keep them away, and scrubbing the bottom maybe three or four times a year will keep you in good shape.

 

[Tonic1]

I remember seeing this, or something similar years ago. It is a waterproof, 12v oscillating scraper. I have no idea about effectiveness, but price is reasonable at $129.

https://waveblade.co.uk/

 

[Bmarler]

One more thing regarding the dive/scrubbing. Someone mentioned a toilet plunger for helping keep you in position. The divers I use for bottom maintenance use those double suction cup handles. Just cheap ones from harbor freight. Push them onto the hull surface and use them to keep you from pushing yourself away from the hull as you’re scrubbing. Easier than setting all those lines under the boat.

 

[backinblue]

Agree with the suction cups, I've used one that is often used for lifting up floor panels because to has a release lever to unstick the cups.

 

[Cigatoo]

What are you using for bottom paint? I’m in Puget sound too, and I don’t have trouble with barnacles like you seem to be having. Sure, the prop and shaft get them but not the hull. A good bottom job should keep them away, and scrubbing the bottom maybe three or four times a year will keep you in good shape.

I agree with this. Here in the Northeast we have our share of barnacles. I have friends with steel hulled boats. They use a commercial anti fouling paint that works well. Lasts for a few years I would love to use it but would be scared to put it on fiberglass. Strong stuff. If you have interest I’ll get the name of the company. I am sure the commercial guys in your part of the world would have a line on good paint.

 

[GoneDiving]

1000 psi won't do it. Take a trip to your local Boatyard and see what psi machine they use, betting its at least 3500, which is what i used.

They can be rented, maybe buy your own hose/wand and nozzles to use with a rental.

What gun tip did you use? I'm thinking a 5" spray would be an adjustable fan like used for washing cars etc?? My cleaner also comes with a fixed orifice wobbler/turbo head. Much more aggressive but this would be reduced underwater.

Did you do any damage to the underlying paintwork? Above water, mine will easily strip painted steel down to bare metal.

Thanks.

https://www.bunnings.com.au/ryobi-pressure-washer-turbo-lance_p0376360

 

[LeoKa]

What really matters is the angle of attack and nozzle pattern.

Spraying systems (spray.com) is a resource I used in industry that may give you some ideas.

What a wealth of information site. Thanks.

 

[LeoKa]

What are you using for bottom paint? I’m in Puget sound too, and I don’t have trouble with barnacles like you seem to be having. Sure, the prop and shaft get them but not the hull. A good bottom job should keep them away, and scrubbing the bottom maybe three or four times a year will keep you in good shape.

Agreed. As I said earlier, a bottom job is coming up next year. It should sure help my situation. For now, monthly diving is what I can do.

 

[LeoKa]

1000 psi won't do it. Take a trip to your local Boatyard and see what psi machine they use, betting its at least 3500,

Did you use any particular nozzle/spray angle/water volume?

 

[LeoKa]

Just throwing this out there.
How about something air powered ?? Sander, scraper ?? Maybe use a scotch brite pad instead of sandpaper. Right angle grinder.
No idea what might be available...

It would eliminate the reverse thrust. I'd think you would spend as much energy holding on as scrapping...

Again, my biggest difficulty is to reach the little corners and angles.
Plus, hard growth cannot be brushed off. Scraper or high pressure water will do it.

 

[Keysdisease]

I'm in South Florida so we have significant hard and soft growth here.
I used a 15* standard tip. Anything wider for me just wasn't effective.
I have seen the wobbler heads on electric pressure washers, my neighbor has one, I don't know how effective it would be.
Depends on the paint, and you will always remove some paint along with growth. You're going to take off significant ablative paint and not so much of a hard paint. Its a fine line between taking off hard growth and paint.

What gun tip did you use? I'm thinking a 5" spray would be an adjustable fan like used for washing cars etc?? My cleaner also comes with a fixed orifice wobbler/turbo head. Much more aggressive but this would be reduced underwater.

Did you do any damage to the underlying paintwork? Above water, mine will easily strip painted steel down to bare metal.

Thanks.

https://www.bunnings.com.au/ryobi-pressure-washer-turbo-lance_p0376360