Getting air out of a deep sea seal

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NPMR

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Reading the surveyor's report on new boat, he notes

" A deep sea seal is fitted and in good condition. It should be noted that after drying out the engine should not be started until any air that has become trapped within the seal has been evacuated"

How do you do that then? I want to test run the engine before launching.
 
NPMR said:
Reading the surveyor's report on new boat, he notes

" A deep sea seal is fitted and in good condition. It should be noted that after drying out the engine should not be started until any air that has become trapped within the seal has been evacuated"

How do you do that then? I want to test run the engine before launching.
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I'm pretty sure that the surveyor is referring to bleeding the seal after launching. If the boat is on the hard, then you can't evacuate the seal but this does not stop you running the engine as long as you provide a source of cooling water, just don't run it in gear for any length of time.
 
hi, to get the air out put the boat in the water then squeeze the seal hard untill it drips water as it drips air is forced out , job done.
 
bluejasper2 said:
hi, to get the air out put the boat in the water then squeeze the seal hard untill it drips water as it drips air is forced out , job done.
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To describe a bit further: place forefinger and thumb on either side of seal and parallel to shaft. Squeeze together whilst trying to drag the seal vertically upwards. Listen for the hiss of escaping air and wait for the sound of squirting water. If you can't get these effects then rotate the prop. shaft 90 degrees or so and try again. The only time that I've had to do the latter was when I'd injected a bit too much grease which had blocked air flow [my theory anyway].
 
bluejasper2 said:
hi, to get the air out put the boat in the water then squeeze the seal hard untill it drips water as it drips air is forced out , job done.
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reeac said:
To describe a bit further: place forefinger and thumb on either side of seal and parallel to shaft. Squeeze together whilst trying to drag the seal vertically upwards. Listen for the hiss of escaping air and wait for the sound of squirting water. If you can't get these effects then rotate the prop. shaft 90 degrees or so and try again. The only time that I've had to do the latter was when I'd injected a bit too much grease which had blocked air flow [my theory anyway].
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I'm not sure whether you guys know about the Deep Sea Seal, but your descriptions sound like the way you'd vent a Volvo or Radiche seal.

To vent a Deep Sea Seal, you have to pull the shaft-mounted part backwards along the shaft to allow air/water to escape from the phosphor bronze seal.

The easier solution is to install the air vent line, using the Y-connector provided with the seal on the cooling water intake to the seal. Then it automatically vents the air.
 
pvb said:
I'm not sure whether you guys know about the Deep Sea Seal, but your descriptions sound like the way you'd vent a Volvo or Radiche seal.

To vent a Deep Sea Seal, you have to pull the shaft-mounted part backwards along the shaft to allow air/water to escape from the phosphor bronze seal.

The easier solution is to install the air vent line, using the Y-connector provided with the seal on the cooling water intake to the seal. Then it automatically vents the air.
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Guys. Please note that the OP is asking ow he can run the engine before launching. In that situation you can't bleed the seal.
 
NPMR said:
Reading the surveyor's report on new boat, he notes

" A deep sea seal is fitted and in good condition. It should be noted that after drying out the engine should not be started until any air that has become trapped within the seal has been evacuated"

How do you do that then? I want to test run the engine before launching.
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It looks as if the surveyor might have phrased things badly and is referring to expelling air after re-launching. Alternatively, he might just be worried about the prop. spinning slowly with the engine running and gear in neutral. I suppose the OP could make a temp. DIY shaft-brake with just enough resistance to stop any slight drag on the shaft when in neutral (or just watch the prop. when starting).

There shouldn't be any seal related reason not to start the engine as long as the shaft isn't turning. Unless vibration is an issue and I think that's unlikely. Perhaps someone else has more experience with this type of seal and can comment.

>>How do you do that then?
Venting the Deep Sea Seal explained already and only relevant when afloat as you can't vent it ashore.

>>I want to test run the engine before launching.
Not letting the shaft turn is the important point. So you can run the engine as long as cooling water is supplied (cool engine & prevent damage to pump impeller).

Does that sound as if the OPs queries have been understood and explained? Or have I picked it up incorrectly?
 
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Thank you guys.

I am constantly in awe of the combined wealth of knowledge around, so thanks.

The summary in my head is;

a) I can run the engine to test, ashore, so long as the impellor is lubricated (water supply) as before with my 1GM10.

b) As the boat has been laid up ashore, I have to ensure that any air is removed from inside the seal before engaging gear etc.

c) If a Volvo or Radiche seal is fitted, then a bit of squeezing as advised. If a Deep Sea Seal, look for the vent and use that, if it is not hooked up to an automatic system.

As the boat is all new to me I will be looking at all these systems for the first time! If I've not understood it, please speak up, and slowly, for the dense student at the back of the class!

And I haven't even begun to get my head round the electronics - radar, GPS, instruments - all interfaced with repeaters and slaves . EEK!
 
Just a little bit of extra information. Deep Sea Seals are not common and some people use the term as a generic term for all kinds of "modern" seals. However there are many different types so you need to be sure exactly which you have. Some rely on lip seals and some on face seals. If it does turn out to be an actual Deep Sea then inspect the bellows very carefully for any sign of cracking or degradation of the rubber. They seal by the two faces being pressed together, but that also means that they can stick together if left for some time without turning or water lubrication. So make sure that they are free by pulling the bellows back. If you are uncertain about what you have, Vyv Cox's site has photos of different types or you can post a photo here and somebody will recognise it.
 
vyv_cox said:
My information about Deep Sea seals is pretty sparse but there is a photo of one and, as Tranona says, photos of most others. See http://coxengineering.sharepoint.com/Pages/Sternglands.aspx
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You can download the Deep Sea Seal fitting and operating instructions here...
http://www.tnorrismarine.co.uk/documents/ManecraftFittinginst..pdf

And there's more detail, including a cutaway drawing, in the brochure...
http://www.tnorrismarine.co.uk/documents/manecraftleaflet_000.pdf
 
We have a Manecraft Deep Sea Seal. It hasn't been 'burped', vented, adjusted or touched at all in over ten years. During that time the boat has done several thousand miles, including a lot of motoring, and has been lifted out and re-launched every year.

Should we now start to worry about it?

:confused:
 
As a slight aside why is a surveyor writing operating instructions into a survey?

'2 self tailing size 42 genoa sheet winches are fitted, these should always have the sheets wound clockwise around them'

Or

'A padlock secures the liferaft to its rack, this should be removed before use'

I appreciate that in this case the OP has learned something but it was also written poorly (unless there is no neutral selectable on the gearbox since the engine can usually be run independantly of the shaft) and smacks of someone 'padding' a report.

Shouldn't a survey be a list of systems and components and a report on their condition?
 
Just a small point about running the engine while ashore, it is not just a matter of keeping the impeller lubricated. Although the engine may be run for a while before it overheats, water is also require to cool the exhaust. Most boat exhausts are made of rubber hose and will soon be damaged by hot exhaust gases unless mixed with water.
 
Dave_Seager said:
Just a small point about running the engine while ashore, it is not just a matter of keeping the impeller lubricated. Although the engine may be run for a while before it overheats, water is also require to cool the exhaust. Most boat exhausts are made of rubber hose and will soon be damaged by hot exhaust gases unless mixed with water.
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In order to run an engine ashore the pick up hose from the raw water pump should be taken to a large bucket that is kept full by a hose.Never connect the hose straight to the pick up pipe .
 
30boat said:
In order to run an engine ashore the pick up hose from the raw water pump should be taken to a large bucket that is kept full by a hose.Never connect the hose straight to the pick up pipe .
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I agree, but I have to say that years ago, before yachting forums had been invented, I and many others used to do exactly this. The likely problem is that the water forces its way past the pump impeller before the engine has started, with a risk of filling the exhaust hose, and ultimately the engine, with water. It never happened to me because it made sense not to ask my glamorous assistant to turn the tap on until the engine had started.
 
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