Mounting a ‘spare’ dripless seal to the shaft.

[oldbilbo]

Comments on this thread illustrate two contrasting and traditional approaches to 'being prepared' for problems at sea.....

One is to consider the potential consequences of specific failures, then to carry the spares, materials and capability to effect repairs ( temp or otherwise).

The other is to consider such consequences, then to decide that the likelihood is small and that such an occurence would be addressed and managed 'if and when'.

It's invalid - albeit 'comforting' - logic to assume that, because Owner A has had no problems with a device installation, that Owners B and C won't have any.
A little web research, even among these pages, illustrates that some DO have such problems and they are occasionally concerning, very expensive and even hazardous. And not everyone has a consulting engineer on hand to ensure that everything is behaving as it should, and to sort it out seamlessly if it isn't.

Just sayin'....

 

[pcatterall]

Ahh Oldbilbo ...thank you... very insightfull!! Part of my original thought was that the companant may only last the minimum guarenteed period but then I recognise ( am informed) that they may/do in fact last 20 years.

The best bet ( to suit my attitudes and preferences) is to fit a componant that has a readilly fitted spare which can be fitted without great expense/inconvienence.
In this way I have peace of mind and will have no concerns that the original part has been working for 20 years.
Many thanks.

 

[KellysEye]

>I note my TM1 seal is only ‘guarenteed’ for 12 months

The series 1 comes with a one- year/1,250-engine hour warranty, so looking at the engine hours so it should last a long time. There is an article about it here:
http://www.pbo.co.uk/gear/dripless-shaft-seals-pbo-buyers-guide-17357

 

[pvb]

Comments on this thread illustrate two contrasting and traditional approaches to 'being prepared' for problems at sea.....

One is to consider the potential consequences of specific failures, then to carry the spares, materials and capability to effect repairs ( temp or otherwise).

The other is to consider such consequences, then to decide that the likelihood is small and that such an occurence would be addressed and managed 'if and when'.

It's invalid - albeit 'comforting' - logic to assume that, because Owner A has had no problems with a device installation, that Owners B and C won't have any.
A little web research, even among these pages, illustrates that some DO have such problems and they are occasionally concerning, very expensive and even hazardous. And not everyone has a consulting engineer on hand to ensure that everything is behaving as it should, and to sort it out seamlessly if it isn't.

Just sayin'....

I reckon this thread is slightly different in that the OP, having chosen to fit a Tides Marine One seal, is now concerned at the possible short life of the seal. This is no doubt a combination of the fact that it's an "entry level" seal, that it hasn't been engineered for replaceable lip seals, and that Tides only guarantee it for 12 months. Hence his idea of mounting a second One seal on the shaft for use if/when the first one starts leaking. However, many would probably consider that, rather than buy a second identical seal of a potentially delicate design, it would be a better long-term plan to replace the One seal now with a substantial trouble-free seal such as the Volvo or Radice. I'd bet that otherwise, the OP will always have a niggling doubt about the integrity of the One seal, and that doesn't bode well for relaxed boating.

 

[pcatterall]

I reckon this thread is slightly different in that the OP, having chosen to fit a Tides Marine One seal, is now concerned at the possible short life of the seal. This is no doubt a combination of the fact that it's an "entry level" seal, that it hasn't been engineered for replaceable lip seals, and that Tides only guarantee it for 12 months. Hence his idea of mounting a second One seal on the shaft for use if/when the first one starts leaking. However, many would probably consider that, rather than buy a second identical seal of a potentially delicate design, it would be a better long-term plan to replace the One seal now with a substantial trouble-free seal such as the Volvo or Radice. I'd bet that otherwise, the OP will always have a niggling doubt about the integrity of the One seal, and that doesn't bode well for relaxed boating.

No, not exactly. I actually think that the TM lip seal has the same potential for long life as the Volvo/radice as ( I believe) the actual wearing bit is the same. I would not consider the TM to be ‘an entry level’ seal; in fact the Volvo would seem to fit that term better ( although its simplicity may well be its virtue!)
My own concerns arose following the detection of ‘crevice corrosion’ on my shaft due to a long period afloat but unused.
The corrosion would have ‘destroyed’ any lip type seal but I spotted it and was able to reposition the seal.
It made me aware of the vulnerability of these types of seal ( another ‘destroyer’ could be grit or detrious matter)
For this reason I think it is prudent that I at least consider ( and ask the panels ideas) about having a back up.
Oldbilbo hits the nail squarely on the head with his understanding of the motivation that may make one owner concerned about things that may not bother another.

 

[Tranona]

No, not exactly. I actually think that the TM lip seal has the same potential for long life as the Volvo/radice as ( I believe) the actual wearing bit is the same. I would not consider the TM to be ‘an entry level’ seal; in fact the Volvo would seem to fit that term better ( although its simplicity may well be its virtue!)

Entry level in the sense that you have the simplified version of the Tides design, the original having replaceable seals. It is a much more robust design as its main use is on higher powered boats. However, it is inevitably much more expensive and not competitive with others, hence the introduction of a cheaper "entry level" alternative for smaller shaft sizes.