How Often Should My Boat's Hull Be Cleaned?

[Fstbttms]

"How often should my boat's hull be cleaned?"

This is a question hull divers are often asked. It is a common misconception that frequent hull cleaning reduces the length of time your anti fouling paint remains viable. But by employing an experienced, knowledgeable hull cleaner using Best Management Practices, quite the opposite is true.

The key to making your anti fouling paint last a long time is to never let it get so dirty that it cannot be cleaned with the softest cleaning media (and by that we mean carpet or a white pad.) A typical hull cleaning frequency here in the San Francisco Bay Area is every three months. This schedule virtually ensures that within the first year, your diver will have to clean the boat with something more abrasive. And that means scrubbing paint off unnecessarily which, of course, shortens your paint's lifespan. A typical bottom job cleaned on a quarterly schedule will last about two years.

You paid a lot of money for your bottom job and you want it last as long as possible. Here in the San Francisco Bay Area, a 2-month cleaning frequency is recommended. This ensures that your diver can use the softest pad when cleaning your hull, often for the entire life of the paint. A less frequent regimen means a more abrasive pad will have to be used, which not only shortens the lifespan of your anti fouling paint but releases more copper into the water than otherwise would be. Further, with the 2-month cleaning cycle, your hull is clean more of the time, thereby improving performance both under power and sail and reducing your fuel consumption and carbon emissions. By gently cleaning your hull just 6 times per year (as opposed to 4 times) your bottom paint can last three years or more, potentially saving you thousands of dollars in haulout/bottom painting costs.

Here's the math for 10 years of ownership of a 40' sailboat:

3-month hull cleaning schedule (painted every 2 years)

$2700 bottom job X 5 = $13,500
$90.00 hull cleaning (4 times/year X 10) = $3600
Total expenditure (10 years) = $17,100

2-month hull cleaning schedule (painted every 3 years)

$2700 bottom job X 3 = $8100
$90.00 hull cleaning (6 times/year X 10) = $5400
Total expenditure (10 years) = $13,500

Total savings = $3600

That's quite a savings. Not to mention your fuel cost savings from operating the boat with a clean bottom more of the time. And consider also that the cost of the bottom job is only going to increase in the future.

The fact is that relatively frequent, gentle cleanings are better for the boat, better for the environment and better for your wallet than less frequent, more abrasive cleanings. Ask your hull cleaner if he is a member of the California Professional Divers Association. CPDA divers are trained and certified in the use of industry standard In-water Hull Cleaning Best Management Practices, making them the best trained, best educated hull cleaners in California.

[Perithead]

Interesting post, I liked the math work there. I wonder if it is really accurate saying that a less abrasive pad lengthens a bottom jobs life that much?

[Fstbttms]

Originally Posted by Perithead

I wonder if it is really accurate saying that a less abrasive pad lengthens a bottom jobs life that much?

100% accurate, here in the Bay Area. Dependent of course, upon the quality of the anti fouling paint being used and how well it was applied. But it only makes sense that cleaning with something soft and less abrasive would remove less paint than cleaning with something coarse and more abrasive. And the only way to ensure being able to use something soft is to not let the hull get even moderately foul in the first place.

Here is a pic of three months growth on a Trinidad bottom in good condition.



A white pad or carpet isn't going to remove that.

[overbored]

seems it does to me. my diver cleans it every month with carpet and the bottom paint lasts 3 years easy. I will paint this spring at just under 4 years.

[aeventyr60]

If you take your boat out more often you won't need to clean the bottom so much....

[jarcher]

That's interesting... I have a few questions.

My boat has Baltoplate on the bottom, which is a hard paint.

I have my hull cleaned weekly during racing season. When they pulled my boat out, it had not been cleaned in about a month. They power washed it, but that left some dried slime where the straps were. Now that the boat is on the hard, what's the safest way to clean that dried slime off?

Where do you guys buy those white scotch pads? I have looked but been unable to find them.

I am going to have to do some touch up on my bottom paint in the spring. Its worn thin in some spots, so I am hoping the barrier coat is still okay.

[JimsCAL]

I'm surprised that in SF you could even get away with a 3-month bottom cleaning schedule. Here in the Northeast, after 3 months the bottom would be a mess. Monthly cleanings are a minimum - more frequently if you race. Must be the warmer water.

[kd3pc]

Originally Posted by Fstbttms

"How often should my boat's hull be cleaned?"

This is a question hull divers are often asked. It is a common misconception that frequent hull cleaning reduces the length of time your anti fouling paint remains viable. But by employing an experienced, knowledgeable hull cleaner using Best Management Practices, quite the opposite is true.

.....

That's quite a savings. Not to mention your fuel cost savings from operating the boat with a clean bottom more of the time. And consider also that the cost of the bottom job is only going to increase in the future.

The fact is that relatively frequent, gentle cleanings are better for the boat, better for the environment and better for your wallet than less frequent, more abrasive cleanings. Ask your hull cleaner if he is a member of the California Professional Divers Association. CPDA divers are trained and certified in the use of industry standard In-water Hull Cleaning Best Management Practices, making them the best trained, best educated hull cleaners in California.

things a little slow out that way? At least make your marketing generic enough to work on the right coast.

The most suggested cleaner in our area, is not even a certified diver...I guess you get what you pay for.

And like any good business person, your numbers make the process look great. Are they accurate? Perhaps or perhaps not...

[jameswilson29]

Here's my 10 years of ownership on my P28:

5 gallons of bottom paint = 5 x $115 = $575

5 gallons of stripper = 5 x $100 = $500

Haulout (block, launch) and power wash every 2 yrs = 5 x $500 = $2,500

Paint scraper, grinder, sandpaper, brushes and tarps = $300

(Maybe a used wet suit and carpet, if motivated = $200)

Total = $3,875, or less than $400 a year, a savings of $9,000 to $13,000.

[Fstbttms]

Originally Posted by jarcher

When they pulled my boat out, it had not been cleaned in about a month. They power washed it, but that left some dried slime where the straps were. Now that the boat is on the hard, what's the safest way to clean that dried slime off?

No idea. I'm sure someone here can offer a suggestion though.

Originally Posted by jarcher

Where do you guys buy those white scotch pads? I have looked but been unable to find them.

They are 3m "Doodlebug" pads. I get them at the local chandlery where I buy zincs. I have also bought them at a janitorial supply store. West Marine carries a knock-off version. Inferior product, IMHO.