Bottom cleaning with a pressure washer

[Bigfish]

What's the ideal pressure? How about under water??

[DavidM]

I believe that the boat yards use high volume, 2-3,000 psi pressure washers. They are surprisingly effective at getting off even hard barnacles.


It think effectiveness would be significantly reduced under water.


David

[Sabre602]

Hanging there in the slings you'll see that they keep the nozzle several feet away from the hull. My concern about using it underwater would be that you'd have to hold it very close to the hull to be effective. This would greatly increase the risk of damage to the boat.

[Boat]

Distance from the nozzle to the barnacle is critical. Power decreases exponentially with the distance. IIRC it's the square or the cube, you get the idea. With the nozzle a foot away you might as well use a garden hose, slight exaggeration.

I resisted buying a pressure washer until several friends assured me it was worth it. I never regretted buying one.


A wet blaster is a useful addition.

[Simi 60]

Depends on how good the blaster is.
Cheap ones can't blow the skin off of custard
More expensive ones can damage concrete.

[Boat]

I think most blasters are never set up correctly. The orifice size needs to be matched to the capacity of the compressor.

Pressure washers and blasters can be very destructive. Don't want someone learning from mistakes on your job.


I like custard and tapioca too. It would be very easy for me to weigh 300lbs. This is an issue for me with a live-aboard lifestyle. Not sure if I can get enough activity. I need the equivalent of walking pastures, more really.

[psneeld]

To really be handy like the ones at marinas, 3-4000 psi and over 3 gal per minute is usually the starting point where I have been/worked.

At the bottom end of those specs, barnacles often need coaxing with very close, long blasts.

Much less than the above specs can be frustrating unless you like power washing all day.

[Bigfish]

Thanks.. I was wondering if it could be done while the boats in the water if you used a nozzle that squirted out the front and the back at the same time so you don't go flying off like a water wiggle...

[AKDoug]

I have used a Hotsy the last couple of years, it uses much lower pressure and is a lot easier on the paint. They raise the water temperature and run at lower pressure. It does a much superior job at removing what accumulates up here, but then again I pull out every year and barnacles don't like moving boats. I found a high pressure unit removed paint...

[FF]

We have used the small 120v ,$100. plug in units for a few years to remove the green slime that forms on stored boats over a summer here in FL.

No damage was seen, tho we back off near window frames .

Should not hurt the bottom a bit , but if you have good ablative paint , much can stay in place to keep working.

[psneeld]

Originally Posted by AKDoug

I have used a Hotsy the last couple of years, it uses much lower pressure and is a lot easier on the paint. They raise the water temperature and run at lower pressure. It does a much superior job at removing what accumulates up here, but then again I pull out every year and barnacles don't like moving boats. I found a high pressure unit removed paint...

You want it to remove paint much of the time.....

If the paint is loose, then you dont have to sand or scrape it off....

If ablative or self polishing and you are blasting off growth...you probably need to get down a layer or two anyway.

If not much growth and good paint...just stand further away. You can always move back but without the pressure and volume for heavy growth...you are just wasting time....if it takes the crap off at all.

At marinas that charge by the foot to power wash...that isnt cost effective.

[Pgitug]

As my mama used to say “The easy way is seldom the best way.”
Use a Hookah and a good flexible scraper.

https://rover.ebay.com/rover/0/0/0?m...2F263892490147

[greysailor]

'
X2 on the Hookah!
Since I've put on a few pounds of "natural floatation"[emoji16]...I rigged a BCD with quick-dump weights to my Hookah line. Makes to easy to stay in position when changing shaft zincs.