Putting bags around the prop

[Nostrodamus]

By the end of the season last year our prop got pretty fouled up with sea crud and was not a pretty site when we took it out.

We are getting towards the end of the season again and another year in the warmer waters of the med and I can now feel that the prop is getting out of balance from more growth.

Over winter I hope to put something around it like a few bags to stop further growth.

I have a saildrive which is a meter or so below the sea level so cleaning it is really difficult just by diving.

Any suggestions on what to put on it next year to prevent some of the fouling if possible.

Anyone else get problems like this and have you found a solution?

 

[BrianH]

By the end of the season last year our prop got pretty fouled up with sea crud and was not a pretty site when we took it out.
We are getting towards the end of the season again and another year in the warmer waters of the med and I can now feel that the prop is getting out of balance from more growth.
Over winter I hope to put something around it like a few bags to stop further growth.
I have a saildrive which is a meter or so below the sea level so cleaning it is really difficult just by diving.
Any suggestions on what to put on it next year to prevent some of the fouling if possible.
Anyone else get problems like this and have you found a solution?

The answer to the above two questions is: Yes and No.

Here in the Adriatic the problem is bad and in the northern Italian lagoons very bad and has got worse with the reduction of biocide toxicity in leisure boat, anti-fouling paint.

Some owners in my marina put plastic bags around their props but they are all mobos with easily accessible props. The rest of us haul out once every year and dive to scrape during the summer. Last year I had to dive twice in the marina to clear the prop before I could get enough drive to get out of the mooring box.

The chief culprits are the typical conical barnacle and tubeworm, the latter of which massively infest the hull in clumps, one or two find a fleck of paint that has gone and others form on their shells until a large colony results.

I shall be interested to see how this thread develops and what others propose.

Edit:
A boat neighbour swears by Velox Plus and claims it works in our marina - I'll probably try it next spring when I haul out and anti-foul - might as well, nothing else has worked to date.

 

[prv]

I have a saildrive which is a meter or so below the sea level so cleaning it is really difficult just by diving.

Have you given it a go?

A few weeks ago I was anchored off a Solent beach and decided to go for a swim. Then, since I'd just bought a fancy waterproof camera (for use in wet cockpits really, rather than underwater), I decided to try to get a pic of my super-dooper new Spade anchor buried in the sand, and broke out the emergency mask and snorkel to be able to see it. Then, coming back to the boat, I realised I could see the outline through the murk of the saildrive below it, and decided to dive down and have a look at the prop:

Having seen that, I decided to go and get an old chisel from on board, and spent about half an hour diving down, scraping a bit, and coming back up. I removed practically all the barnacles and tubeworm, and got all the wide flat areas (not the fiddly bits in the joints) back to shiny brass.

The point is, I am (to put it bluntly) fat and unfit, and working in murky UK waters. Surely in the warm clear Med it should be easy?

Pete

 

[BrianH]

Surely in the warm clear Med it should be easy?

I agree. In fact, it is quite an agreeable couple of hours in an anchorage for me. I keep a paint scraper with a lanyard that fits my wrist and with snorkel and face mask get my propeller totally clear of crud on a regular basis. It's just having to do it in the marina because the propeller churns the water and effects no drive to get out to sea that it becomes unpleasant. A quick visit to the showers is immediately necessary afterwards.

In my marina a local amateur scuba diver makes a bit on the side from those who prefer to pay rather than get down under.

 

[Nostrodamus]

I have tried it and the warmer water and clear see make it eaier to see. I also find it difficult keeping under long enough to do anything and I keep hitting the hull. I suppose a divers weighted belt would help but all I can imagine is me sat on the bottom with the weights not being able to get up.
If possible I would like to avoid this partially or all together by putting something on the prop at haul out which would stop or at least reduce the growth.

 

[Tony Cross]

I agree. In fact, it is quite an agreeable couple of hours in an anchorage for me. I keep a paint scraper with a lanyard that fits my wrist and with snorkel and face mask get my propeller totally clear of crud on a regular basis. It's just having to do it in the marina because the propeller churns the water and effects no drive to get out to sea that it becomes unpleasant. A quick visit to the showers is immediately necessary afterwards.

In my marina a local amateur scuba diver makes a bit on the side from those who prefer to pay rather than get down under.

Me too, except I use a wallpaper scraper, it removes most of the lumpy stuff.

 

[Mrnotming]

I've done this in Malta, water temp 19C. I used an ex-helicopter survival suit (Macsalvors Cornwall).I used a tether and a weight belt with one weight,quick release type. But after spending almost an hour in the water I became hypothermic and had to quit.It took me as long afterwards to regain my normal operating temperature,and I did not feel very well during this time.
Next time I'd use a heavy neophrene wet suit instead to extend my working time.Now the boat is dry-sailed with immersion max 3 months.Had International EU this year with trilux on the saildrive and prop.Fair amount of slime after the period mid May to late August.No bad encrustations.

 

[John100156]

The answer to the above two questions is: Yes and No.

Here in the Adriatic the problem is bad and in the northern Italian lagoons very bad and has got worse with the reduction of biocide toxicity in leisure boat, anti-fouling paint.

Some owners in my marina put plastic bags around their props but they are all mobos with easily accessible props. The rest of us haul out once every year and dive to scrape during the summer. Last year I had to dive twice in the marina to clear the prop before I could get enough drive to get out of the mooring box.

The chief culprits are the typical conical barnacle and tubeworm, the latter of which massively infest the hull in clumps, one or two find a fleck of paint that has gone and others form on their shells until a large colony results.

I shall be interested to see how this thread develops and what others propose.

Edit:
A boat neighbour swears by Velox Plus and claims it works in our marina - I'll probably try it next spring when I haul out and anti-foul - might as well, nothing else has worked to date.

Tried Velox when I had my T34 and so did Hurricane - no major improvement where we are located in the Med. Not sure if it was Velox Plus. Mind you that's on MoBo's. Couple of chaps bag their props which definitely works, but a PITA so I just resort to 2 or 3 lifts per annum!

 

[dougg]

When we overwintered in Ragusa, I wish id put a bag or 2 on the prop, it was completely covered in barnacles etc and was very hard to clean off in the water.
Last year in Crete there was virtually no growth on the prop which I cleaned up, well polished up, very easily in the water with some course wet and dry.
Nos. I believe your heading to Sicily? so I would definitely bag it.

 

[prv]

I used an ex-helicopter survival suit (Macsalvors Cornwall). But after spending almost an hour in the water I became hypothermic and had to quit.It took me as long afterwards to regain my normal operating temperature,and I did not feel very well during this time.
Next time I'd use a heavy neophrene wet suit instead

What did you wear under the helicopter suit? I assume this was basically equivalent to a membrane drysuit, and with suitable underclothing should be warmer than any wetsuit. You never see divers wearing anything other than a drysuit in cold water nowadays (commercial guys with a hot-water hose from the surface excepted!) and 19ºc hardly counts as cold! However, the suit itself is not intended to keep you warm, it's there to keep what you wear under it dry. The proper thing is a special polyester and thinsulate fleecy suit (generally with a showerproof outer surface to ward off minor leaks and seepage) but you could no doubt improvise with a couple of pairs of tracksuit bottoms and some woolly jumpers and fleeces.

Pete

 

[Gerry]

Yes we did this in Panama whilst in Shelter Bay Marina for a few months. Just a black plastic bag secured with a cable tie. Easy to rip off if you need to start the e4ngine in an emergency-won't foul the prop.Dived down, free diving to put it on, a depth of about three feet.
It kept the fouling off extremely well and we would certainly do it again....

 

[chinita]

Have you given it a go?

A few weeks ago I was anchored off a Solent beach and decided to go for a swim. Then, since I'd just bought a fancy waterproof camera (for use in wet cockpits really, rather than underwater), I decided to try to get a pic of my super-dooper new Spade anchor buried in the sand, and broke out the emergency mask and snorkel to be able to see it. Then, coming back to the boat, I realised I could see the outline through the murk of the saildrive below it, and decided to dive down and have a look at the prop:

Having seen that, I decided to go and get an old chisel from on board, and spent about half an hour diving down, scraping a bit, and coming back up. I removed practically all the barnacles and tubeworm, and got all the wide flat areas (not the fiddly bits in the joints) back to shiny brass.

The point is, I am (to put it bluntly) fat and unfit, and working in murky UK waters. Surely in the warm clear Med it should be easy?

Pete

Yes, yes.....very interesting.

Now, can we see a pic of the Spade please.

 

[William_H]

A bag around the prop does 2 things against the barnacles. Firstly it excludes light which stops weed growing and secondly it tends to concentrate the emissions from any existing antifouling paint. I have tried a whole bag around the boat. Worked well in warm waters but just too much trouble to attach and remove.
I imagine a bag made of old tarp plastic with a line up each side to the gunwhale to hold it up over the leg. I would add another line to go aft from the foot of the bag so that hopefully it can be removed in a hurry without getting in the water.
re diving on the hull it is all about water temp. Warm water makes it a pleasur eto dive but makes the weed grow fast. I can go about 6 to 8 weeks after new A/f before I want to scrub it. After another 4 months of that much of the a/f paint is gone so no build up at least. I usually just dive with tee shirt and mask/ snorkel. Often in summer almost every day so not a real chore. (32 degrees south)
A weight belt is usefull especially if you wear a wet suit or without if you carry fat. The latch for the weight belt should be easy to release. However you should just carry enough lead to enable diving but still be able to swim on surface reasonably easily. ie for me no wet suit one weight with light wet suit 3 weights.each about 1kg. With thick diving we suit 4 weights.
I try to avoid wearing wet suit becuase it is so difficult to get on and off. Am I getting fat? good luck olewill

 

[Greenheart]

Not so long ago, the subject of "green" antifouling raised the point that saltwater organisms don't thrive at all in fresh water.

My impractical thought had been to have a tough, openable and sealable, waterproof bag which fits tightly round the hull. I think somebody marketed the idea in the nineties, but such was the impracticality, it hasn't caught on...

...but while its inventor had thought in terms of using small quantities of biocide, dripped into the water around the boat within the bag to kill the crusties, some clever person pointed out that if you just poured fresh water into the bag, all the saltwater creatures would expire.

Granted, the trouble of parking your boat inside its own wetsuit each time you berth, may not appeal...BUT...

...during weeks/months in one berth, how hard would it be to put a tough polythene bag around the prop, sealed tightly round the shaft, and featuring a one-way valve and a pipe to the pushpit...where a funnel lets you pour a litre or two of fresh water down, to deprive the crusties of food? If after a week the bag may have let salt water seep in, pour in another dose of fresh from above.

No need for any chemical nasties. If it works.

 

[Ariadne]

I have a black plastic bag around my prop (saildrive), and I guess all is well inside it? I'll be removing it next week after 3 months in Chaguaramas so we'll see if it works. The rest of the hull looks like Green Peace could slap a preservation order on it at any time soon; I found a hatchling turtle feeding of it earlier on today!!!!

During the season I/we scrub/scrape the hull weekly to keep any growth off it. I use a 2Kg weight to keep me where I want to be and I can easily work right down to the keel (2.1m) so keeping the prop clean at just over 1m is no problem.

In fairness guys, you should all really be fit enough to spend a minute at a time that depth in Med without problems. As for spending an hour in some sort of un insulated heli-suit; are you mad! Go buy a nice 3mm one piece long wet suit, a set of fins and a weight belt and save yourself a load of trouble.

 

[macd]

I saw a yacht in Lisbon a few years ago with a bag encapsulating the entire underwater area of the boat. Unfortunately the owner wasn't around to ask how effective it was, but I'd always assumed it relied on rain water draining from the decks into the bag for any effectiveness (through-hull drains would obviously help). To help kick-start the process, you could run the engine until it's emptied the bag of seawater, then run freshwater into it from a hose. I imagine that the difference in densities would tend to press the bag against the hull, so the volume needed to effectively 'fill' it wouldn't be great.

 

[BrianH]

Me too, except I use a wallpaper scraper, it removes most of the lumpy stuff.

Actually, that's what mine is too. Having used it as a loose paint remover I wrongly think of it as such. Steel triangular blade (must be kept sharp and rust free) with the tapered end set into a wooden handle that has lost all vestige of its original paint; an essential instrument in my toolbox.

 

[rogerthebodger]

I usually just dive with tee shirt and mask/ snorkel. Often in summer almost every day so not a real chore. (32 degrees south)
olewill

Olewill That must be a site no speedo is that at North Swanbourne.

Not quite 32 degrees south actually Durban is 30 degrees but close) so give us a wave across the Indian ocean.

I also do the same but I find that using a stiff pool brush on a pole I can reach a lot of my hull so I can go 2 years between full scrub and anti foul.

 

[antaris]

FYI I am now 6 months in warm Greek waters and that Velox thing seems to work fine. There is one spot on the axle where it fell off and tubeworm is already developed. The rest of the prop/axle system is all still white.

One important hint is to Paint Velox well before re-immersing in the water (let it dry for at least 24 hrs). I applied the last coat just before re-entering water and everybody told me that parts would fall of... (See previous paragraph!).

Expensive, I paid something in the region of 25 euros for the little tin... well... if it works

 

[Nostrodamus]

so this winter I will try the bag in and tag it approach.... tag it so I don't forget it is there.
Might even put some snake oil on.