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ghostlymoron
22-04-12, 19:01
Sorry if this topic has already been aired to death but I just can't use the forum search facility.
Anyway. I have no experience of this set up but have seen boat with it which seems to fit my spec in every other respect.
Are they safe? Unlikely to fail in a spectacular way.
Thanks

Seajet
22-04-12, 20:08
I had a Carter 30 with a Volvo saildrive.

I've read on these forums that saildrives are mainly for the convenience of the boatbuilder, and reckon that's probably true.

I've never heard of the big seal letting go on anyone, but it is a worry and cost every 10 years or so.

I found the core plugs on my Volvo rusting through, but that was probably just an anode issue with the boat before I got her, frankly too late !

The boss holding the folding prop' cracked, when I had access to all the various welding & sorting dept's of BAe Kingston - a lot of expertise & high tech' kit - I was told it was such **** nasty zinc metal nothing could be done with it so had to buy new; 480 in 1990...

If I was ever looking at a boat with an inboard again I'd prefer a traditional shaft drive ( though that's not without snags ) but if I set my heart on a wonderful boat I wouldn't let a saildrive put me off.

maby
22-04-12, 20:09
I've never heard them described as unsafe and I've never heard of "spectacular" failures. Don't have one personally - not usually fitted on boats in the 33 foot range. I think the claim is that they are less subject to prop walk and they permit better use of space since there is no prop shaft occupying space under the aft cabin. They certainly are more complex than a simple shaft drive and maintenance is higher.

Comrade Red
22-04-12, 20:14
I've got an elderly saildrive.

No problems.

No glands to pack.

No drive shafts to vibrate and go out of alignment.

No weeps.

Don't fret if the boat ticks all other boxes.

tom52
22-04-12, 20:53
Quieter. Can only change oil out the water. Big rubber seal needs changing every seven years (in theory) and its a biggish/expensive job.
Prop tends to be more central so no prop walk, so a long way from rudder so no prop wash.

chinita
22-04-12, 21:01
You will be ok if it is an LM. They have saildrives - but within a watertight engine compartment under the cockpit sole.

All may not be lost if the seal fails (apart from the engine - that is :eek:).

sailorman
22-04-12, 21:02
I've got an elderly saildrive.

No problems.

No glands to pack.

No drive shafts to vibrate and go out of alignment.

No weeps.

Don't fret if the boat ticks all other boxes.

last repacked the stern gland 11 yrs ago
no alignment probs
no drips
no aluminium leg
no big seal to leak or remove the gearbox / leg to replace it

Comrade Red
22-04-12, 21:17
....
no big seal to leak

On that last point, does anyone know of anyone who has had their main saildrive rubber seal leak or fail?

maby
22-04-12, 21:25
On that last point, does anyone know of anyone who has had their main saildrive rubber seal leak or fail?

I've known a few leak - they have a finite life expectancy. So do seals on shaft drives - the difference is that a shaft drive seal is typically a lot cheaper and easier to replace.

The bottom line is that saildrives are a fact of life on modern larger boats - from the owner's point of view, they have a few advantages over shaft drive - though nothing major. They are a bit more complicated and expensive on maintenance - but not ruinously so. If the boat that you want has saildrive, that is not a reason to not buy it, but budget a bit more for maintenance.

mdonnelly
22-04-12, 21:40
Quieter. Can only change oil out the water. Big rubber seal needs changing every seven years (in theory) and its a biggish/expensive job.
Prop tends to be more central so no prop walk, so a long way from rudder so no prop wash.

I have a saildrive on a 33 foot boat. When i engage reverse there is a marked movement to starboard. Is this prop walk? Find it quite useful.

Tranona
22-04-12, 23:06
Sorry if this topic has already been aired to death but I just can't use the forum search facility.
Anyway. I have no experience of this set up but have seen boat with it which seems to fit my spec in every other respect.
Are they safe? Unlikely to fail in a spectacular way.
Thanks

Yes, it has been done to death. Saildrives have been in use for over 30 years and arguably now dominate the new boat market, with more builders progressively moving towards them. This is partly because of the increase in size of boats, but mainly because of the benefits they offer. It is a fallacy that they are significantly cheaper or necessarily easier to install for the builder, but they do offer benefits of better space utilisation.

The major benefits for users are generally smoother and quieter installations, thrust parallel to water line and reduced prop walk. No stern tube to seal so no drips, so more compatible with today's bilgeless boats.

Things to watch out for are seals in the bottom of the leg, anode wear and problems if the wrong paint is used on the leg housing. The seal does in theory need regular replacement, but they do not systematically fail. Most people who have replaced seals report the old one was just fine. Latest designs have much larger anodes and the drive oil can be changed from inside, both of which are improvements. Biggest potential downside is the high cost of replacing the drive if it fails (rare) but when you actually cost it not that much more than gearbox and stern gear replacement of a shaft drive.

More important things to worry about when buying a boat than the drive system - except that with many desirable boats you don't have a choice!

Dipper
23-04-12, 07:39
When I bought my first diaphragm from the Volvo agent he said he had never heard of one fail apart from a brand new one that the owner had lubricated so it slipped in place easily. It also slipped out easily! They are relatively easy to replace by a competent DIYer but expensive (c170 for the 120S kit). The only difficulty I have had with mine is very limited access to the back of the engine.

All the round the world racing yachts seem to have saildrives and they survive the Southern Ocean. I've heard of more problems with shafts falling out of boats.

maby
23-04-12, 08:17
I have a saildrive on a 33 foot boat. When i engage reverse there is a marked movement to starboard. Is this prop walk? Find it quite useful.

Yes, that's prop walk. Strangely, the sailing community seems completely polarised on the issue - if your boat has it, it is useful, if your boart doesn't, it's a liability. Our boat has virtually no prop walk and I'm very pleased that it doesn't.

tom52
23-04-12, 11:07
Yes, that's prop walk. Strangely, the sailing community seems completely polarised on the issue - if your boat has it, it is useful, if your boart doesn't, it's a liability. Our boat has virtually no prop walk and I'm very pleased that it doesn't.

I have saildrive and I miss prop walk.

I suppose if your saildrive is near the stern then you can have saildrive and prop walk.

maby
23-04-12, 11:14
The recent discussion on prop walk here turned into another marathon! I know the theory and even used it on our previous boat which had a viscious kick in reverse. Our current boat has virtually none and I far prefer it like this - OK, there are tight turns I cannot make any more so I avoid circumstances where I need to make them. On the plus side, when I need to stop quickly, I know I can do so without having to fend off from the boat next to me... I got fed up with ending up parked at right angles across the lock after having to come in with a moderate tail wind! :)

Halo
23-04-12, 14:03
Recently moved from shaft to saildrive. No regrets other than more maintanance as discussed by others and need for prop to have an anti vibtration feature.
Handling is great, it seems smoother than a long whirling shaft and I am confident that I can run the engine with more revs without doing damage to the flexible anti vibration coupling.
Boat layout could not be as good with shaft - I expatct this is main reason they are selected by boat builders
Having gone this way I would not let the presence or absence of a sail drive layout sway a boat purchase one way or the other.

EugeneR
23-04-12, 14:41
They are a bit more complicated and expensive on maintenance - but not ruinously so. If the boat that you want has saildrive, that is not a reason to not buy it, but budget a bit more for maintenance.

Just for interest, how much is "a bit more" per year, typically?

maby
23-04-12, 14:55
Just for interest, how much is "a bit more" per year, typically?

Never actually owned one myself - just sailed friends boats with saildrive - so I'll defer to someone that has actually had to pay the bills. As I understand it, you are looking at an extra thing to oil-change each service plus a gasket change every five to ten years. It's the gasket change that can get expensive depending on the model of boat - in some cases it requires significant dismantling.

galadriel
23-04-12, 15:17
I changed my saildrive seal last year, it was 17 years old and looked as good as the new one that replaced it. I changed the seal on a friends boat in Feb, took a day and a half. They are no big deal, dont let club bar stories scare you.

maby
23-04-12, 15:19
I changed my saildrive seal last year, it was 17 years old and looked as good as the new one that replaced it. I changed the seal on a friends boat in Feb, took a day and a half. They are no big deal, dont let club bar stories scare you.

That does assume that you do it yourself - a day and a half labour in a half-decent boatyard is a significant cost!

fireball
23-04-12, 15:23
That does assume that you do it yourself - a day and a half labour in a half-decent boatyard is a significant cost!

I assure you that at least 1/2 of that day was sat in the local restaurant deciding which way round the prop goes on .... I have the emails to prove it* ;)












* if requiring proof please give me 2 days to make them up ... er I mean find them ... :D

Monique
23-04-12, 16:25
Yes, that's prop walk. Strangely, the sailing community seems completely polarised on the issue - if your boat has it, it is useful, if your boart doesn't, it's a liability. Our boat has virtually no prop walk and I'm very pleased that it doesn't.

As you mention, prop walk polarises the sailing community.

Mine has moderate starboard walk but gets stronger with a large throttle burst. Love to use this feature to moor precisely as I gently walk off the stern to a waiting bollard...:D

Easticks28
23-04-12, 16:27
I've got an elderly saildrive.

No problems.

No glands to pack.

No drive shafts to vibrate and go out of alignment.

No weeps.

Don't fret if the boat ticks all other boxes.

+1, and I would add that mine is on the original seal - now 27 years old :eek:

Tranona
23-04-12, 18:06
Just for interest, how much is "a bit more" per year, typically?

Annual maintenance, little difference. Does not need an oil change every year and anode is variable - sometimes every year but my first one lasted 5 years in the Med. Possible seal change in the lower leg around 200 if part of a service. Diaphragm change is around 800 professional, 250 including oil change DIY. So average around 120 a year if you replace the diaphragm as recommended.

Comrade Red
23-04-12, 18:33
Just for interest, how much is "a bit more" per year, typically?

Some years the outer rubber flange (not required for sealing at all) comes unstuck for a few inches so I use either some sikaflex or contact adhesive (whatever is to hand) to stick it back on when I'm doing the anti-fouling.

Each year I check the oil thru the oil dipstick on the sail drive unit, then suck a bit out with a suction pump to check it. Never had it even slightly discoloured so I leave it in and don't fret about changing it, which (with the 110s) can only really be done when the boat is out.

I check around the metal ring inside that compresses the main (inner) sealing gasket and wipe off any oil / diesel that is on it (it took me 15mins this year and I scratched my hand).

And that's it.

While the change interval for the inner seal is officially 7 years, I have never heard of even a weep from a seal as a first hand account, and I know from my local (much respected Volvo specialist) marine engineer that he has never seen one that he would be worried about. Tales of 12+ years are common, and then people usually change "just in case".

For sure changing it would be a right PITA on my boat, requiring it to be out on the hard and the engine to be lifted, but there is space for that so it isn't the end of the world.

And of course it wouldn't really be a whole day and a half of yard labour as someone posted, because the yard would know what they are doing, have the tools, and you would probably be doing some other work at the same time, like changing skin fittings or anti-fouling.

There is a strange snobbery about drive shafts, usually from those who look down their noses at AWB's/ Ben / Jen / Bav (or anything mass market) that hasn't been around the globe 20,000 times sailed by a hair-shirt boater who has spurned electricity and lives a parsimonious existence, steered purely by a wind vane made from an old biscuit tin ;)

noelex
23-04-12, 19:02
Sail drives are cheaper, less headaches and problems for the boat manufacturer, but dearer, more headaches and problems for the owner.

Rowana
23-04-12, 19:15
Why take a drive shaft that is turning in the right direction and turn it through 90degrees, poke it through the bottom of the boat, then turn it through another 90degrees back to the original direction? Seems a daft idea to me.

You probably gather that I'm not a fan of saildrives!

Seatrout
23-04-12, 19:30
What is a 'P' bracket? They seem to be unreliable items given the frequency of my fellow club members cursing them. Saildrive-tastic!

Tranona
23-04-12, 19:39
Sail drives are cheaper, less headaches and problems for the boat manufacturer, but dearer, more headaches and problems for the owner.

Both statements unsupported by evidence - just your opinion!

Tranona
23-04-12, 19:44
What is a 'P' bracket? They seem to be unreliable items given the frequency of my fellow club members cursing them. Saildrive-tastic!

P bracket is one of the devices used to support a shaft that comes out of the boat at an angle. Became popular when bottoms of boats were flattened so there was nothing in the structure to support the shaft. Can be a problem - difficult to line up and sometimes not well attached to the structure. Hence now boats are getting older problems arise with bearing wear, vibration and bracket coming loose.

Almost out of "fashion" now in sailing auxilliaries replaced by superior saildrives or in some designs moulded in shaft logs.

galadriel
23-04-12, 20:34
What has not had a mention here is the cost that is associated with shaft drive maintenance. The P bracket bearing will need to be changed at least as often, if not more often as the seal on a sail drive, I suspect. You have to factor in if you cannot do the job yourself the cost of removing the prop, then the prop shaft, pressing out the bearing then getting the shaft lined up with gearbox again.

I do not know, but would guess that job would need to be done more regularly than changing the seal on a saildrive. Can anyone tell us?

doug748
23-04-12, 20:53
As noelx has said, Saildrives are expensive to replace or mend, plus you have less scope to extemporise your repair in the average raggiedy arse boatyard.

There is little to jib about in a newish boat but it would be an extra worry in an old one. However it is not a deal stuffer.

Saildrives are nice and quiet unlike my propshaft.

PS

For Galadriel, cutless bearings seem to be changed between 3 years (me) 15 years and never depending who you speak to.

maby
23-04-12, 20:57
What has not had a mention here is the cost that is associated with shaft drive maintenance. The P bracket bearing will need to be changed at least as often, if not more often as the seal on a sail drive, I suspect. You have to factor in if you cannot do the job yourself the cost of removing the prop, then the prop shaft, pressing out the bearing then getting the shaft lined up with gearbox again.

I do not know, but would guess that job would need to be done more regularly than changing the seal on a saildrive. Can anyone tell us?

Not sure how true this is - depends very much on how much use you make of the engine on a shaft drive boat. Unlike the shaft drive, the seal on a saildrive is going to degrade and need replacement even if the engine is never started. That's not to say that this is a deal breaker - the saildrive seal is relatively expensive to replace, but will last a fair few years.

galadriel
23-04-12, 22:16
I'm not sure how many years it takes for a saildrive seal to degrade. Like I said in my earlier post, mine was 17 years old when I changed it and was as good as the new one which replaced it.

doug748 reckons on between 3 - 15 years for cutlass bearing life (thanks doug, I could not remember what they were called!!). Having the yard change the saildrive seal is going to be expensive, I wont argue that, but if you have to employ them to change the cutlass bearing several times within the life of a saildrive seal, I suspect the arithmetic would be quite close in terms of overall cost.

I should point out, I have had two boats with saildrives and had no problems at all, I had one boat with a shaft and could not get rid of the vibration or drip from the packing.

Tranona
23-04-12, 23:09
As noelx has said, Saildrives are expensive to replace or mend, plus you have less scope to extemporise your repair in the average raggiedy arse boatyard.



Think that sums it up well, having gone through the expense of a complete new drive. However, this is a rare occurence and in my case not unconnected with 3500 hours and 7 seasons as a charter boat. Once it has failed, not economic to rebuild, not because it is technically difficult, but because failure, which is usually the clutch pack seizing or water getting in the bottom end, wrecks just about all the moving parts.

On the other hand the regular failings of some shaft drive installations can usually be fixed by changing one or two bits - cutless, shaft, engine mounts, couplings, shaft seals, which individually are not expensive and are easier DIY.

However, you could say similar things about older cars where many components could be replaced or repaired individually - but not possible on newer cars. My parents Ford Pop needed servicing every 1000 miles (17 shillings and sixpence) - but a decoke every 10000 miles, new clutch every 20000, new exhaust every 2 years etc, whereas my latest CMax diesel has run over 60000 miles with only oil changes, new pads and tyres and a battery after 7 years.

Newer style boats do not lend themselves to conventional shaft drives because of their flat underbodys. Saildrives keep the weight near the centre of the boat and do not require a heavy bulkhead/floor across the stern sections to take the P bracket, nor a vulnerable hole for the shaft to go through the bottom of the boat. Jeanneau are the last volume builder using P brackets and most of their newer models are using saildrives. Similar with Beneteaus who traditionally used a moulded shaft log but are now moving to saildrives - which are now available for up to 75hp engines.

njsail
24-04-12, 10:50
I was a little tentative when before I purchased our Bavaria 40 Ocean with a sail drive. After getting used to the difference in handeling (the prop is right behind the keel -- not right in front of the rudder) the smooth quiet ride was easy to get used to. There is no cavitation and little prop walk (which I do miss a little). The prop walk isn't as big an issue since the bavaria has a fin keel and turns very quickly compared to my prior full keel boat that at time could have used a team of horses to manuever into a tight dock in a cross wind.

I just changed out the sail drive gasket this year (12 years). Here are a couple pics. I have a volvo saildrive. The gasket was in great shape and only showed slight signs of dry rot on the water side of the gasket. The gasket itself is really thick and very well built and would probably lasted many more years but I changed it out and not I don't have to worry about it for a while.

Would I purchase another boat with a sail drive .... abolutely yes. Just make sure to maintain it properly and you should have many years of good service. After all that's what we all want.

johnphilip
24-04-12, 11:20
There is a strange snobbery about drive shafts, usually from those who look down their noses at AWB's/ Ben / Jen / Bav (or anything mass market) that hasn't been around the globe 20,000 times sailed by a hair-shirt boater who has spurned electricity and lives a parsimonious existence, steered purely by a wind vane made from an old biscuit tin ;)

I see Comrade Red has done a careful study of the forum psyche, and reached the view many of us hold of the prejudiced outlook many posters....... But where would we be without thse comfortingly predictable views that appear and let the rest of us feel superior with our progressive outlooks. Or in truth are we all as bad? Long live wooden boats (as long as someone else owns them )

GrogRat
24-04-12, 22:05
Interesting no one has mentioned clutch life, i have first hand experience of poor life of yanmar cone clutches in the SD-40 , the yanmar book of jokes aka operating manual insists upon regular inspection and lapping of the clutch cone into the gear assembly , in addition the cruising forums are full of horror stories over failed clutches at 200 hours or so, incompetent service agents and outrageous spares costs e.g. 1000 or so for a new clutch pack , If I ever re-engine the boat, I would never use yanmar again because of sail drive issues.

aluijten
25-04-12, 09:05
I was a little tentative when before I purchased our Bavaria 40 Ocean with a sail drive. After getting used to the difference in handeling (the prop is right behind the keel -- not right in front of the rudder) the smooth quiet ride was easy to get used to. There is no cavitation and little prop walk (which I do miss a little). The prop walk isn't as big an issue since the bavaria has a fin keel and turns very quickly compared to my prior full keel boat that at time could have used a team of horses to manuever into a tight dock in a cross wind.

I just changed out the sail drive gasket this year (12 years). Here are a couple pics. I have a volvo saildrive. The gasket was in great shape and only showed slight signs of dry rot on the water side of the gasket. The gasket itself is really thick and very well built and would probably lasted many more years but I changed it out and not I don't have to worry about it for a while.

Would I purchase another boat with a sail drive .... abolutely yes. Just make sure to maintain it properly and you should have many years of good service. After all that's what we all want.

I agree on the point about durability as I've just replace it myself as well. But there is one thing that bothers me.
Volvo uses stainless bolts to connect the upper side to the lower side. The way they do this induces corrosion at the lower part where the bolt heads are located. See enclosed picture. This was made after cleaning and before treatment with epoxy primer.

http://www.ybw.com/forums/attachment.php?attachmentid=17208&d=1333484492

galadriel
25-04-12, 10:07
I agree on the point about durability as I've just replace it myself as well. But there is one thing that bothers me.
Volvo uses stainless bolts to connect the upper side to the lower side. The way they do this induces corrosion at the lower part where the bolt heads are located. See enclosed picture. This was made after cleaning and before treatment with epoxy primer.

http://www.ybw.com/forums/attachment.php?attachmentid=17208&d=1333484492

I have replaced the seal on two different Volvos now, neither had corrosion like this, in fact there was no corrosion at all.

aluijten
25-04-12, 10:14
I have replaced the seal on two different Volvos now, neither had corrosion like this, in fact there was no corrosion at all.

Interesting. Which models were this?

I've had it both on a S120 as a MS25S. The latter is 10 years old and was mounted without any coating other then what came out of the box.
Most of the coating was still in very good shape but on the picture you can see not all of it. This boat was mostly kept on fresh water.

the_branflake
25-04-12, 10:17
I've just replaced the sail drive seal on mine. I also had slight corrosion in the places shown by aluijten. Mine is a S120c. Just to add, some muppet had bypassed the negative solenoid on mine, I was lucky for once that the leg hadn't suffered.

Needless to say its now been corrected, it just needed taking apart and cleaning. You can see the two tiny wires in the picture here http://www.ybw.com/forums/showthread.php?t=310933 - no wonder it turned over slow.

doris
25-04-12, 11:54
Noone seems to mention the requirement for a rope cutter.
I had never had anything round a prop before I got a sail drive. Over the last 6 seasons we have picked up stuff 5 times and are very grateful for our stripper. I am very convinced that a sail drive gathers this stuff more readily that a P bracket set up. That said I am more than happy to have a sail drive and will do again, just with a stripper from the outset.

jerrytug
25-04-12, 12:02
Exactly Doris,if you wanted to design a device to entangle semi -floating pot buoy lines,bits of net etc,it would look something like a saildrive. And if you do get entangled,aren`t saildrives too delicate to winch off the entanglement? A good cutter would be a must surely,but even then it`s an accident waiting to happen. Jerry.

galadriel
25-04-12, 12:16
Both were 120S probably C version. One on a MS2 gearbox 1993, the other a later 1999 gearbox.

galadriel
25-04-12, 12:20
Exactly Doris,if you wanted to design a device to entangle semi -floating pot buoy lines,bits of net etc,it would look something like a saildrive. And if you do get entangled,aren`t saildrives too delicate to winch off the entanglement? A good cutter would be a must surely,but even then it`s an accident waiting to happen. Jerry.

Strange that, the only time I destroyed a gearbox and P bracket when I wound a rope between P bracket and prop, this in turn tore the side out of the aluminium ZF gearbox. But its true, in the polluted in which we sail a rope cutter is advisable on any drive.

fireball
25-04-12, 12:29
Noone seems to mention the requirement for a rope cutter.
I had never had anything round a prop before I got a sail drive. Over the last 6 seasons we have picked up stuff 5 times and are very grateful for our stripper. I am very convinced that a sail drive gathers this stuff more readily that a P bracket set up. That said I am more than happy to have a sail drive and will do again, just with a stripper from the outset.

Strange - had a boat with a shaft drive & p bracket - each year on haulout there would be remnants of line on the shaft ...

now got a boat with saildrive - no lines present .... but then we do have a cutter too ... not that I've ever noticed it do anything ...

both are two bladed fixed prop - so it's not that either ...

Talbot
25-04-12, 12:32
Strange that, the only time I destroyed a gearbox and P bracket when I wound a rope between P bracket and prop, this in turn tore the side out of the aluminium ZF gearbox. But its true, in the polluted in which we sail a rope cutter is advisable on any drive.

A Catamaran in the far east that had no rope cutter, and was using a dyneema rope on their tender, got the rope around the prop and destroyed the engine mounts and then ripped out the gasket on one engine. This led to the boat effectively sinking. I have heard of similar problems with ropes on shaft drives.

One area that does need attention on a saildrive, is the cooling water inlet. In most designs, this is a small pipe with a gate valve on the saildrive leg. This has blocked in areas with large crustacean problems. There is a significant body of thought that believes this system needs to be disabled and a proper inlet valve (preferably marelon) fitted.

Tranona
25-04-12, 13:07
One area that does need attention on a saildrive, is the cooling water inlet. In most designs, this is a small pipe with a gate valve on the saildrive leg. This has blocked in areas with large crustacean problems. There is a significant body of thought that believes this system needs to be disabled and a proper inlet valve (preferably marelon) fitted.

That really does depend on where you keep the boat. There is more than enough capacity in the intakes to cope with some fouling, but there are locations where small mussels grow, so if your boat is moored in one of those locations there may be benefit in having a conventional seacock in addition and connected via a Y valve to give choice. However, if it is mussels that cause the problem they can just as easily block a seacock, particularly if it has an external grid.

Comrade Red
25-04-12, 13:36
That really does depend on where you keep the boat. There is more than enough capacity in the intakes to cope with some fouling, but there are locations where small mussels grow, so if your boat is moored in one of those locations there may be benefit in having a conventional seacock in addition and connected via a Y valve to give choice. However, if it is mussels that cause the problem they can just as easily block a seacock, particularly if it has an external grid.

I have this and have used it on occasions, most recently when some agricultural plastic wrapped around the leg. The prop cleared itself enough to keep going but the inlets were blocked.

The comment from the yard (as she was lifted for anti-fouling) was a reminder to remove the plastic wrapping before I played with my toys.:)

galadriel
25-04-12, 14:06
Getting a plastic bag or plastic around the saildrive leg is not uncommon, it has happened to us a couple of times. In both cases we eased the throttle to neutral, then carefully into reverse, once engaged plenty of revs for a few seconds has cleared the problem. I guess the plastic is blown back the way it came.

When doing this it is advisable not to run in reverse so long that you take all way off.

Talbot
25-04-12, 14:17
One area that does need attention on a saildrive, is the cooling water inlet. In most designs, this is a small pipe with a gate valve on the saildrive leg. This has blocked in areas with large crustacean problems. There is a significant body of thought that believes this system needs to be disabled and a proper inlet valve (preferably marelon) fitted.


That really does depend on where you keep the boat. There is more than enough capacity in the intakes to cope with some fouling, but there are locations where small mussels grow, so if your boat is moored in one of those locations there may be benefit in having a conventional seacock in addition and connected via a Y valve to give choice. However, if it is mussels that cause the problem they can just as easily block a seacock, particularly if it has an external grid.

I think you must have missed my statement in the third sentence! This has blocked in areas with large crustacean problems.

:cool:

Tranona
25-04-12, 14:35
I think you must have missed my statement in the third sentence! This has blocked in areas with large crustacean problems.

:cool:

Apologies - I did miss that bit - concentrated too much on the opening statement!

Tranona
25-04-12, 14:39
Getting a plastic bag or plastic around the saildrive leg is not uncommon, it has happened to us a couple of times. In both cases we eased the throttle to neutral, then carefully into reverse, once engaged plenty of revs for a few seconds has cleared the problem. I guess the plastic is blown back the way it came.

When doing this it is advisable not to run in reverse so long that you take all way off.

Plastic bags are normally no problem and can be dealt with as you suggest - if the prop has not chewed the stuff up already. Bigger problem is heavier stuff like fertiliser sacks which can wrap round the prop blades. Happened to me before I had the rope cutter fitted. Big bang as we hit it, but a bit of in and out of gear broke it up enough to get some drive, then had a diver clear it in harbour.

Halo
25-04-12, 15:35
Agricultural plastic bag/sheet can be a nightmare. I montered my Westerly 25 coast to coast through the Leeds Liverpool canal and got some of it round the prop half way through the Foulridge tunnel - nightmare requiring me to get in the water/ooze and free it in the dark - an actiivity which convinced me to fork out for a stripper.
Back to shaft/sail drive options not all props are compatible with sail drives e.g brunton autoprop. This would not put me off another sail drive but is worth bearing in mind

rob2
25-04-12, 16:21
An acquaintance wrote a nice article on changing the seals on the saildrive on his boat. Being an engineer, his writing covered all the points you want to ask after reading the official text! However, after relaunching the outer/fairing seal adhesion failed (we all make mistakes) and he could barely make any weigh back to the hoist to fix it.

It reminded me of the swiming costume my mother knitted me as a child. Once in the water it was like a sea anchor around your ankles!

Rob.

Tranona
25-04-12, 18:07
Back to shaft/sail drive options not all props are compatible with sail drives e.g brunton autoprop. This would not put me off another sail drive but is worth bearing in mind

Not so Bruntons have props to fit Volvo, Yanmar and Bukh saildrives in sizes 13-20" diameter.

Very wide range of alternate props available for saildrives, both folding and feathering. The only popular one that I knoww about that does not work is the new Featherstream, but no doubt that will come in the future.

eddystone
04-09-13, 09:39
I have just been on a diesel maintenance course and the instructor wasn't very keen on saildrives - I think he believed that the seal was too high a risk.
That apart, as one of the boats I am looking at has a saildrive, I wondered how much difference it would make to annual servicing/winterisation routine. The course gave me the confidence to do this myself and save a fair wad of money and the only thing I can see as different is the fact the gearbox oil has to be changed when it's out of the water. However, I may have misunderstood but is the water inlet on the leg the main cooling inlet for the engine. I had intended to keep the boat in the water all year round apart from a month or so lift out for maintenance and would fill the raw water cooling system with fresh water/antifreeze mix then when I came to use the boat in winter I would reconnect the raw water inlet etc. and re-winterise when I left. If the raw water inlet is inaccessible way down in the leg, that isn't feasible.

Tranona
04-09-13, 10:11
Yes, the water intake is in the leg, although some boats have a separate intake through a conventional valve. No need to worry about water freezing in it in our climate. Nowhere in the UK does water (particularly seawater) freeze to that depth. Nothing special required for winterising. The engine coolant has its own antifreeze/inhibitor. You cannot fill the leg water passages with antifreeze anyway as the valve is in the boat. You could drain the seawater section inside, but really is not necessary. On some models you can change the saildrive oil from inside - however oil changing is not necessary every year.

There are some people who have an irrational bias against saildrives. However they have been in use for over 30 years now and are fitted to the majority of new boats (in Europe anyway). The main diaphragm is very reliable, and although many are changed at the recommended interval, reports suggest that there is no evidence of any degradation. The seals in the bottom of the leg are more vulnerable, but fitting a rope cutter reduces the chances of anything like fishing line getting in, which is a cause of seal failure. Regular checking of oil will indicate if the seals are leaking as the oil goes milky. Changing lower seals is not a big job, obviously with the boat out of the water.

Talbot
04-09-13, 11:59
....... I may have misunderstood but is the water inlet on the leg the main cooling inlet for the engine. I had intended to keep the boat in the water all year round apart from a month or so lift out for maintenance and would fill the raw water cooling system with fresh water/antifreeze mix then when I came to use the boat in winter I would reconnect the raw water inlet etc. and re-winterise when I left. If the raw water inlet is inaccessible way down in the leg, that isn't feasible.

If you have a sea water strainer

http://www.youtube.com/watch?v=00xpK1C9ktY

then you can easily change over for a flush with antifreeze.

However, the valve on the leg is easily accessible - although I really do not like the design, and have installed separate 3/4 marelon thru-hulls for the salt water cooling.

Stork_III
04-09-13, 20:12
I have just been on a diesel maintenance course and the instructor wasn't very keen on saildrives - I think he believed that the seal was too high a risk.
That apart, as one of the boats I am looking at has a saildrive, I wondered how much difference it would make to annual servicing/winterisation routine. The course gave me the confidence to do this myself and save a fair wad of money and the only thing I can see as different is the fact the gearbox oil has to be changed when it's out of the water. However, I may have misunderstood but is the water inlet on the leg the main cooling inlet for the engine. I had intended to keep the boat in the water all year round apart from a month or so lift out for maintenance and would fill the raw water cooling system with fresh water/antifreeze mix then when I came to use the boat in winter I would reconnect the raw water inlet etc. and re-winterise when I left. If the raw water inlet is inaccessible way down in the leg, that isn't feasible.

I have had saildrive boats for12years and always keep the boat in the water over winter. Have never yet winterised the engine, it is a lot warmer in than out.

paulclan
04-09-13, 21:20
Very comprehensive thread! One issue which may occur, and from memory I think it was forumite Saxon Pirate who confirmed the diagnosis I had then made.Water was squirting out of the engine bearers and the aft cabin bilges were full, tasted, seawater, oops!
Seems if you hit enough semi submerged logs, tree branches or whatever, the bond, where the bearer module is bonded to the hull at the exit aperature of the saildrive leg can fail.
The ingress of water was a worry , easily disposed of by sponge and bucket.Upon lifting the vessel,examination of the area of hull/bearer join revealed a fissure on the aft portion, undoubtedly caused by the whole assembly trying to respond to a serious impact.The outer flange bonding was not affected at all.The repair comprised: flushing with fresh water,drying,grind back as neccessary for keying, glass tape, epoxy layer over.I lost the fairing piece on the outside of the hull subsequently, one part glue not seemingly doing the job.However I found wet suit material as a substitute is just as effective and bonds well with normal neophrene glue.

Comrade Red
05-09-13, 00:09
I have just been on a diesel maintenance course and the instructor wasn't very keen on saildrives - I think he believed that the seal was too high a risk.
That apart, as one of the boats I am looking at has a saildrive, I wondered how much difference it would make to annual servicing/winterisation routine. The course gave me the confidence to do this myself and save a fair wad of money and the only thing I can see as different is the fact the gearbox oil has to be changed when it's out of the water. However, I may have misunderstood but is the water inlet on the leg the main cooling inlet for the engine. I had intended to keep the boat in the water all year round apart from a month or so lift out for maintenance and would fill the raw water cooling system with fresh water/antifreeze mix then when I came to use the boat in winter I would reconnect the raw water inlet etc. and re-winterise when I left. If the raw water inlet is inaccessible way down in the leg, that isn't feasible.

Don't let a saildrive put you off a boat. They are well tried and tested.

rivonia
05-09-13, 07:30
Quieter. Can only change oil out the water. Big rubber seal needs changing every seven years (in theory) and its a biggish/expensive job.
Prop tends to be more central so no prop walk, so a long way from rudder so no prop wash.

I do believe that the oil can be sucked out whilst still in the water?

2nd_apprentice
05-09-13, 11:00
How to change your saildrive oil while afloat:

translate.google.com/translate?sl=de&tl=en&js=n&prev=_t&hl=de&ie=UTF-8&u=http%3A%2F%2Fwww.yacht.de%2Fschenk%2Ftrick%2Ftri ck25.html

stuartwineberg
05-09-13, 11:08
One point that hasn't been made but was emphasised to me on my Volvo saildrive years ago was that you aren't supposed to put the drive in gear when sailing. A lot of people do that to get rid of the noise of the prop turning when under sail but it puts a sideways shear force on the saildrive leg and can jam it in gear. You have to get used to the noise.

2nd_apprentice
05-09-13, 11:14
The procedure seems to be as follows:

Get a plastic nipple of the same size and thread as the drain plug.
Fit hose to nipple. The hose has to be long enough to reach to the pontoon.
Fill the saildrive completely and close it.
Dive under the boat and unscrew the drain plug. Since water is heavier than oil it won't get into the saildrive.
Attach nipple with hose and get onthe pontoon.
Open oil filler cap
Suck out the old oil via hose and keep topping up with fresh oil.
Continue until all the old oil has been drained.
Shut oil filler cap.
Go for another swim and replace the drain plug.
Open oil filler cap and check for correct oil level.
Have a drink, you've deserved it!

ghostlymoron
05-09-13, 11:14
How to change your saildrive oil while afloat:

translate.google.com/translate?sl=de&tl=en&js=n&prev=_t&hl=de&ie=UTF-8&u=http%3A%2F%2Fwww.yacht.de%2Fschenk%2Ftrick%2Ftri ck25.html
Google translate is not perfect and gave me a few guffaws (how does google translate that!) but I get the gist. I'm waiting for episode 2 when Fritz changes his oil seals underwater.
I'm still not sold on saildrives though.

ghostlymoron
05-09-13, 11:17
The procedure seems to be as follows:

Get a plastic nipple of the same size and thread as the drain plug.
Fit hose to nipple. The hose has to be long enough to reach to the pontoon.
Fill the saildrive completely and close it.
Dive under the boat and unscrew the drain plug. Since water is heavier than oil it won't get into the saildrive.
Attach nipple with hose and get onthe pontoon.
Open oil filler cap
Suck out the old oil via hose and keep topping up with fresh oil.
Continue until all the old oil has been drained.
Shut oil filler cap.
Go for another swim and replace the drain plug.
Open oil filler cap and check for correct oil level.
Have a drink, you've deserved it!

Apprentice, your translation is not half so amusing as the original.

savageseadog
05-09-13, 11:38
One point that hasn't been made but was emphasised to me on my Volvo saildrive years ago was that you aren't supposed to put the drive in gear when sailing. A lot of people do that to get rid of the noise of the prop turning when under sail but it puts a sideways shear force on the saildrive leg and can jam it in gear. You have to get used to the noise.

A free wheeling prop slows you down I always lock my saildrive in gear while sailing, I think the foregoing is nonsense I'm afraid.

2nd_apprentice
05-09-13, 11:45
Apprentice, your translation is not half so amusing as the original.

;)

ghostlymoron
05-09-13, 12:10
;)
or to put it another way 'your translation as the original is not half so amusing'

prv
05-09-13, 12:57
A free wheeling prop slows you down I always lock my saildrive in gear while sailing, I think the foregoing is nonsense I'm afraid.

No idea about saildrives (and I have a folding prop so the issue doesn't arise) but Yanmar definitely say that their shaft gearboxes must be left out of gear while sailing. I have a copy of the technical bulletin at home.

Pete

Stork_III
05-09-13, 13:22
One point that hasn't been made but was emphasised to me on my Volvo saildrive years ago was that you aren't supposed to put the drive in gear when sailing. A lot of people do that to get rid of the noise of the prop turning when under sail but it puts a sideways shear force on the saildrive leg and can jam it in gear. You have to get used to the noise.

If you have folding prop, VP say put in reverse when sailing.

JomsViking
05-09-13, 16:48
True, MSA08-003 from Yanmar says that their engines must never be put in gear while the engine is off. Hurth states that their boxes must never be in fwd when off, but reverse is OK.
So to me Yanmar engines are not compatible with folding propellers :)

So I guess it's very important to read the manual for your specific gearbox/engine combo

No idea about saildrives (and I have a folding prop so the issue doesn't arise) but Yanmar definitely say that their shaft gearboxes must be left out of gear while sailing. I have a copy of the technical bulletin at home.

Pete

prv
05-09-13, 16:52
True, MSA08-003 from Yanmar says that their engines must never be put in gear while the engine is off.
So to me Yanmar engines are not compatible with folding propellers :)

I don't think that follows. What they don't want is the shaft trying to spin with the gearbox locked. But if the prop is folded, then the shaft won't be trying to spin.

Pete

JomsViking
05-09-13, 16:53
True. But sometimes (and I've experienced this on several boats) the prop unfolds and start spinning when not in reverse. Should've explained that.


I don't think that follows. What they don't want is the shaft trying to spin with the gearbox locked. But if the prop is folded, then the shaft won't be trying to spin.

Pete

prv
05-09-13, 16:59
True. But sometimes (and I've experienced this on several boats) the prop unfolds and start spinning when not in reverse.

But if it is in reverse, then it's not going to start spinning.

Pete

JomsViking
05-09-13, 17:03
:confused: But You're not allowed to put the Yanmar gears in reverse when sailing and engine is off, so following their requirement the folding propeller starts spinning.. (Am I being daft and/or missing something in translation??)


But if it is in reverse, then it's not going to start spinning.

Pete

JomsViking
05-09-13, 17:09
A clarification, when asking what to do if the prop started spinning the answer from Yanmar was "fit a shaft brake".

prv
05-09-13, 17:16
:confused: But You're not allowed to put the Yanmar gears in reverse when sailing and engine is off

...because the torque of a spinning conventional prop causes it to lock up. I've experienced this myself. However, if you have a folding prop, then putting the gearbox in reverse causes the prop to fold and stay folded, and thus there is no torque and no problem.

Pete

JomsViking
05-09-13, 17:20
That was my belief as well, but Yanmar tolds us NOT to put it gear even with a folding propeller and if the prop started spinning anyways to fit a shaft brake.



...because the torque of a spinning conventional prop causes it to lock up. I've experienced this myself. However, if you have a folding prop, then putting the gearbox in reverse causes the prop to fold and stay folded, and thus there is no torque and no problem.

Pete

Probably not allowed to post the advisory, but it says:


Yanmar requires that if sailing with the engine OFF (not running) the transmission shifter must be in the neutral position or internal damage to the gear or sail-drive will result

prv
05-09-13, 17:25
Yanmar tolds us NOT to put it gear even with a folding propeller

They don't say "even with a folding propeller".

Pete

JomsViking
05-09-13, 17:29
Sorry for the hijack, but I think this is important.

See quote from Yanmar advisory in my previous post, basically they state that the engine must be in neutral when off - no if's or but's.
And the answer we got from Yanmar when asking for clarification was "even with a folding propeller".


They don't say "even with a folding propeller".

Pete

P.S: I agree that it probably wouldn't hurt the gearbox to put it in reverse with a folding prop, but Yanmar says you should not.
P.P:S: I don't own a Yanmar, but have helped installing/servicing/repairing a few

prv
05-09-13, 17:41
See quote from Yanmar advisory in my previous post, basically they state that the engine must be in neutral when off - no if's or but's.

There's a difference between neglecting to mention whether something is OK, and actively saying that it is not OK. The advisory does not specifically say that you mustn't be in gear even with a folding prop. Here's a copy of it: http://portal.mastry.com/bulletins/Kansaki%20Gears/shift%20position%20for%20sailing.pdf


And the answer we got from Yanmar when asking for clarification was "even with a folding propeller".

OK, I didn't know that you'd asked them directly. But I would wonder who in Yanmar gave that answer. If you've ever worked for a big company you'll understand how much easier it is to give the safe answer rather than the accurate one.

Pete

JomsViking
05-09-13, 17:47
I know large Corporations and agree that the safe answer is often given, however the Word must has a very specific meaning in my World:



MUST: This word, or the terms "REQUIRED" or "SHALL", mean that the definition is an absolute requirement of the specification.
So I actually interpret the advisory's:


Yanmar requires that if sailing with the engine OFF (not running) the transmission shifter must be in the neutral position or internal damage to the gear or sail-drive will result
the same - hence we asked for clarification



There's a difference between neglecting to mention whether something is OK, and actively saying that it is not OK. The advisory does not specifically say that you mustn't be in gear even with a folding prop. Here's a copy of it: http://portal.mastry.com/bulletins/Kansaki%20Gears/shift%20position%20for%20sailing.pdf



OK, I didn't know that you'd asked them directly. But I would wonder who in Yanmar gave that answer. If you've ever worked for a big company you'll understand how much easier it is to give the safe answer rather than the accurate one.

Pete

Salty John
05-09-13, 18:54
A free wheeling prop slows you down I always lock my saildrive in gear while sailing, I think the foregoing is nonsense I'm afraid.

Actually, according to Strathclyde University, MIT and Michigan Wheel (propeller manufacturers) there is less drag when the prop is allowed to rotate.

I blogged on this a while ago:http://saltyjohn.blogspot.co.uk/2013/07/propellers-what-drag.html