Bottom Cleaning

[Tom Farley]

Hello All,

It Seems to me that Bottom Cleaning might be the only reason to Haul out every couple of years unless there is some other damage to steering etc.

Has anyone ever tried underwater pressure washing with what I call a mud pump . Basically a gas powered 2" Suction Pump that can be choked down to a 1 " high volume /pressure spray jet. Hanging on to the boat under water is still a question. Hand HEld Suction Cups. ?

It could also be used as a bilge pump in case of flooding. Deck cleaning , Water Fights , Random Celebrations .

Just THinking

I remain

Tom In the Berkshires.

[atavist]

I've wondered about this as well... maybe not using an underwater pressure wash but how about attaching a water hose to your snorkel which then runs up onto the boat and then just getting down there with a stiff brush and scrubbing the hull whenever in clear waters.

[Gallivanters]

Tom,

NASA trains their astronauts underwater to simulate working in zero gravity. And to easily understand the dynamics of the device you propose - simply hold onto the end of a garden hose while submerged in a swimming pool and try to control the direction of your low pressure spray jet. You may quickly find yourself hog-tied with the hose so be sure to have several friends and a paramedic standing by to rescue you before you open the nozzle!

In a previous lifetime I found myself 50 ft underwater wrestling a 15,000 PSI "Hydro Blaster" tasked with removing marine growth from production rigs in the offshore oilfield near Santa Barbara... back when I was young, handsome and bulletproof.

Those were the days!

The hydro blaster was basically a giant pressure washer on steroids with the one major difference being that the water discharge came to a "T" fitting which acted to counter-balance the output and effectively stabalize the diver's business end of the unit. It was a beastly tool that could cut through two ft. of marine growth (and your leg off) in a single pass!

The reason for such high pressure was because the tool was designed for underwater use... which is, like, eight times more dense than air. Much of the energy was absorbed right after leaving the nozzle.

Therefore, I do not believe your mud pump will have much practical effect at removing marine growth from a boat bottom. Sorry. However it could certainly be used in some of the other applications you mention.

Just being able to stay on target while cleaning a boat in the water can really wear you out and takes a lot more effort than one would expect. Kinda like working in outer space, I immagine. Some chandleries carry suction-cup handle tools just for this job. They're a bit expensive in my opinion and wear out quickly.

On our boat, we usually carry an old fashioned rubber toilet plunger which works quite well at holding me on the job while allowing me to apply enough pressure to clean the hull with my free hand. They're cheap and available throughout the world, plus they float if you drop 'em AND they make a great washing machine when used in a plastic bucket on deck!

Lastly - I find that scraps cut from old carpet work best for cleaning soft slime from around our hull. It's robust enough to stand up to the job yet soft enough to be easy on the paint.

Atavist - if you are wondering about the possibility of simply breathing below the surface through a long snorkel... I suggest you also try this in a swimming pool with the same crew standing by. ou will find that your lungs simply cannot overcome the water pressure being exerted upon them to "pull" air much more than two feet below the surface.

However, a good dinghy pump can sometimes provide enough air volume and pressure to overcome the water pressure to supply a source of air to a diver to a depth of six ft. (or more) provided you trust the person on the pump and have been trained to do an emergency free ascent - EXHALING THE ENTIRE WAY TO THE SURFACE. I've done it myself but I will not suggest, recommend or condone anyone attempting to do so in this forum.

To Life!

Kirk

[Swagman]

IMHO there re few yachts who don't need to be slipped annually to check and replace anodes - and thats an appropriate time to check and repaint if fouling is bad.

We pick up some slime during a years cruise - and find its an easy thing to stay on top of simple by free diving.

And free diving is the only way guys unless you've got the right scuba kit and training.

To try and work underwater, even in minimal depths but using home contrived breathing apparatus - is positively dangerous and should never ever be considered.

Never.

Cheers

JOHN

[MMNETSEA]

Originally Posted by Swagman

IMHO there re few yachts who don't need to be slipped annually to check and replace anodes - and thats an appropriate time to check and repaint if fouling is bad.

We pick up some slime during a years cruise - and find its an easy thing to stay on top of simple by free diving.

And free diving is the only way guys unless you've got the right scuba kit and training.

To try and work underwater, even in minimal depths but using home contrived breathing apparatus - is positively dangerous and should never ever be considered.

Never.

Cheers

JOHN

-------------------------------

To add another caution to John's very good advice - is the danger although small, of inhaling toxic waste containing minerals , chemicals , bacteria and bacterial toxins whilst surfacing from the cleaning process. The safest bet is to clean the hull out of the water out of the water, or have it done using proper diving equipment.

[Muroc]

I once paid a professional diver $50 (AUD) to spend 30 minutes with a soft bristled broom to clean off the worst of my buildup - but at the end of the day this was only a temporary measure and just delayed the inevitable need to slip the boat, scrub it and re-apply anti-foul (it did give me an extra 6 months though which just saw me through to the beginning of the race season, so I started with the advantage of a freshly anti-fouled boat ).

[JeanneP]

Our cruising on sv Watermelon was all in the tropics. We hauled the boat about every three years.

In order to survive that long we put lots of ablating antifoul on when we did haul. Then periodically Peter would wash the scum off the hull. The prop needed more attention that the hull. With that long between haulouts we also had to change the zincs while in the water. Some places the zincs lasted a shorter time than other areas and sometimes one would fall of for ?whatever reason, so it's prudent to check the zincs periodically.

Peter and I had both taken SCUBA lessons before we started cruising, but did not want to carry tanks on the boat. For the first few years we were out we had a commercially built gasoline powere hookah that we used, but we weren't that happy with the space needed to store it safely, its weight, and the work involved in setting it up, not to mention the gasoline we had to carry and use for it. So for cleaning the hull, for quite some time I would pump air to him using our dinghy pump, the air running through a regular SCUBA air regulator to prevent too much pressure into his lungs. That works quite well, but it's a lot of work.

Peter decided to make his own 12V hookah using a truck tire inflator pump, accumulator bottles (the pump was high pressure, low volume), and the regulator. This worked exceptionally well. The pump is a diaphragm pump, so there is no risk of oil contaminating the air. Although cleaning the hull does not entail significant depths so risks are minimal, there is some danger, and nobody should be messing around with compressed air without being qualified. SCUBA lessons are cheap insurance.

When we used the gas hookah, it was clear that the SCUBA training and diving experience was important. On one dive I was at the full extent of the air hose, about 40 feet, when I lost air. Since this is something that one practices in SCUBA lessons, I did not panic and I exhaled as I slowly surfaced to prevent an air embolism. I don't care how well-informed a person is, only practice and repetitive experience makes diving reasonably safe. However, with that training and experience, I don't believe that a hookah, even a home-made one, is more unsafe than most other gear on a sailboat.