Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 09-10-2012, 08:21   #1
Registered User
 
stillbuilding's Avatar

Join Date: Jan 2008
Location: Hong Kong
Boat: Custom Freya 20m
Posts: 961
High pressure wash underwater

Would it be possible and effective to use a high pressure water cleaner underwater to clean the hull? Would save the costs involved in a haul out obviously.
__________________

__________________
stillbuilding is online now   Reply With Quote
Old 09-10-2012, 08:43   #2
Senior Cruiser
 
Sailmonkey's Avatar

Cruisers Forum Supporter

Join Date: Sep 2009
Location: Houston
Boat: '76 Allied Seawind II, 32'
Posts: 5,778
Re: High pressure wash underwater

commercial divers do this all the time to ships/boats. they use a double ended wand so they don't get blown away from the hull.
__________________

__________________
Sailmonkey is online now   Reply With Quote
Old 09-10-2012, 18:41   #3
Senior Cruiser
 
bstreep's Avatar

Cruisers Forum Supporter

Join Date: Oct 2007
Location: San Antonio, TX/Port Aransas, TX
Boat: 1990 Macintosh 47, "Merlin"
Posts: 2,274
Re: High pressure wash underwater

I've heard of folks trying this, but being blown to the bottom. Someone around here does this using a hammock, that their assistant (topside) moves.
__________________
Bill Streep
San Antonio/Port Aransas, TX
bstreep is offline   Reply With Quote
Old 09-10-2012, 20:20   #4
Writing Full-Time Since 2014
 
thinwater's Avatar

Join Date: Nov 2008
Location: Deale, MD
Boat: PDQ Altair, 32/34
Posts: 4,338
Re: High pressure wash underwater

That's about as anti-green as you can get, many times more polluting than scrubbing. Have you not seen the paint that comes off when doing this on land? While it may be the only way for some industrial applications, recreational practice seems quite foolish. In fact, power washing the topsides of a boat is generally risky too (leaks).

I'd rather talk about something else.
__________________
Gear Testing--Engineering--Sailing

Writing full-time since 2014.
Bookstore:http://sail-delmarva.blogspot.com/20...ook-store.html
thinwater is offline   Reply With Quote
Old 09-10-2012, 20:43   #5
Registered User
 
Jentine's Avatar

Join Date: May 2004
Location: Cruising on the hook
Boat: Beneteau 393, "Blackthorn"
Posts: 744
Images: 5
Re: High pressure wash underwater

Power washing underwater removes much less material than out of the water. The resistance of the water the stream passes through reduces the resultant pressure. It is much less effective than one would assume.
Jim
__________________
Jim

We are what we repeatedly do.
Excellence, therefore, is not an act but a habit."
--Aristotle
Jentine is offline   Reply With Quote
Old 09-10-2012, 20:53   #6
Registered User
 
stillbuilding's Avatar

Join Date: Jan 2008
Location: Hong Kong
Boat: Custom Freya 20m
Posts: 961
Quote:
Originally Posted by thinwater
That's about as anti-green as you can get, many times more polluting than scrubbing. Have you not seen the paint that comes off when doing this on land? While it may be the only way for some industrial applications, recreational practice seems quite foolish. In fact, power washing the topsides of a boat is generally risky too (leaks).

I'd rather talk about something else.
I was wondering re use on Copper epoxy bottom rather than paint.
YMMV
__________________
stillbuilding is online now   Reply With Quote
Old 09-10-2012, 20:55   #7
Registered User
 
stillbuilding's Avatar

Join Date: Jan 2008
Location: Hong Kong
Boat: Custom Freya 20m
Posts: 961
Quote:
Originally Posted by Jentine
Power washing underwater removes much less material than out of the water. The resistance of the water the stream passes through reduces the resultant pressure. It is much less effective than one would assume.
Jim
I would guess so. Higher pressure maybe?
__________________
stillbuilding is online now   Reply With Quote
Old 09-10-2012, 21:01   #8
Marine Service Provider
 
fstbttms's Avatar

Cruisers Forum Supporter

Join Date: Oct 2006
Location: Under a boat, in a marina, in the San Francisco Bay
Posts: 3,594
Re: High pressure wash underwater

Actual "pressure washers" should never be used on a painted surface underwater. Because the ambient water pressure surrounding the pressure stream robs it of most of its power, the washer nozzle (where pressure is extremely high) must be kept very close to the painted surface. Pressures are so high in this scenario that the washer will blast your anti fouling paint off the hull and can actually cut into a fiberglass hull quite easily.

Hull cleaners will sometimes use the "Caviblaster" to clean hulls (typically extremely foul hulls.) It resembles a pressure washer but uses a zero-thrust wand and works on a different principle. It will not remove paint.



Cavidyne LLC
__________________
fstbttms is offline   Reply With Quote
Old 09-10-2012, 21:09   #9
Resin Head
 
minaret's Avatar

Cruisers Forum Supporter

Join Date: Aug 2007
Location: Seattle WA
Boat: Nauticat
Posts: 7,199
Images: 52
Re: High pressure wash underwater

Quote:
Originally Posted by fstbttms View Post
Actual "pressure washers" should never be used on a painted surface underwater. Because the ambient water pressure surrounding the pressure stream robs it of most of its power, the washer nozzle (where pressure is extremely high) must be kept very close to the painted surface. Pressures are so high in this scenario that the washer will blast your anti fouling paint off the hull and can actually cut into a fiberglass hull quite easily.

Hull cleaners will sometimes use the "Caviblaster" to clean hulls (typically extremely foul hulls.) It resembles a pressure washer but uses a zero-thrust wand and works on a different principle. It will not remove paint.



Cavidyne LLC


fstbttms, what do you think of the Wave Blade for those of us who are headed where there are no divers like you?



Waveblade – Hull Maintenance Made Easy
__________________
minaret is offline   Reply With Quote
Old 09-10-2012, 21:23   #10
Marine Service Provider
 
fstbttms's Avatar

Cruisers Forum Supporter

Join Date: Oct 2006
Location: Under a boat, in a marina, in the San Francisco Bay
Posts: 3,594
Re: High pressure wash underwater

Quote:
Originally Posted by minaret View Post
fstbttms, what do you think of the Wave Blade for those of us who are headed where there are no divers like you?
A waste of money, IMHO. First off, you should never let your hull reach a state where it is so encrusted with barnacles that you would consider purchasing such a tool. And if by chance you did allow your hull to become so encrusted, a $5 taping knife will cut through them faster. It might take a little more elbow grease, but you don't have to worry about losing a $5 taping knife.
__________________
fstbttms is offline   Reply With Quote
Old 09-10-2012, 22:53   #11
Resin Head
 
minaret's Avatar

Cruisers Forum Supporter

Join Date: Aug 2007
Location: Seattle WA
Boat: Nauticat
Posts: 7,199
Images: 52
Re: High pressure wash underwater

Quote:
Originally Posted by fstbttms View Post
A waste of money, IMHO. First off, you should never let your hull reach a state where it is so encrusted with barnacles that you would consider purchasing such a tool. And if by chance you did allow your hull to become so encrusted, a $5 taping knife will cut through them faster. It might take a little more elbow grease, but you don't have to worry about losing a $5 taping knife.

I was thinking more of the running gear, the hull stays pretty clean with a light scrub as long as the paint is maintained. I like the half round blade for shafts and the blade for props. But it sounds like what you are saying is that it's easy work with just a scraper and the power assist is not needed?
__________________
minaret is offline   Reply With Quote
Old 09-10-2012, 23:16   #12
Marine Service Provider
 
fstbttms's Avatar

Cruisers Forum Supporter

Join Date: Oct 2006
Location: Under a boat, in a marina, in the San Francisco Bay
Posts: 3,594
Re: High pressure wash underwater

Quote:
Originally Posted by minaret View Post
But it sounds like what you are saying is that it's easy work with just a scraper and the power assist is not needed?
If the running gear is not excessively fouled, you would have no need for a power tool. Even if it was excessively fouled, unless you are doing multiple boats with excessively fouled running gear, a power tool is not necessary. And even then, a power tool is not necessary. IMHO, of course.

A wire brush and a Five-in-One tool is really all you need.

__________________

__________________
fstbttms is offline   Reply With Quote
Reply

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off




Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 09:16.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.