Prop shaft sealing option.

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Discussion

bazza white

Original Poster:

3,558 posts

128 months

Thursday 28th July 2016
quotequote all
Running through so ideas for a small build. What are the options for running a shaft through the transom. Seen a few running about £200 non drip but also spotted a Volvo option for £60 ish which just looks like a rubber pipe.

Are they really as simple as one end clamped to chat and other to shaft tub. How does the shaft spin freely. Are they just greased up.


On a French site there is one that just looks like a bit of samco hose. This could be an option.

Simpo Two

85,422 posts

265 months

Thursday 28th July 2016
quotequote all
bazza white said:
Running through so ideas for a small build. What are the options for running a shaft through the transom. Seen a few running about £200 non drip but also spotted a Volvo option for £60 ish which just looks like a rubber pipe.
I have the Volvo one (fitted on a new build in 2012 and performing faultlessly) - see halfway down at http://coxengineering.sharepoint.com/pages/sterngl...



paintman

7,687 posts

190 months

Friday 29th July 2016
quotequote all
I enjoyed the video of changing the Volvo one in the watersmile

Works in the same way as a seal on a rotating shaft in your car (crankshaft, driveshafts etc), the seal lips facing towards the liquid you want to keep in (or in the case of that one, out!)
Interesting about the necessity to burp some of them incl the Volvo one, so may prove an irritation - with a risk of forgetting - if the boat is kept on a drying mooring.

Edited by paintman on Friday 29th July 09:00

bazza white

Original Poster:

3,558 posts

128 months

Saturday 30th July 2016
quotequote all
Cheers seems I've been over thinking it. The diagrams above help. Jet drive would be great but may be over complicating it.

I'll have a million more questions for project mini boat.

hidetheelephants

24,357 posts

193 months

Saturday 30th July 2016
quotequote all
paintman said:
I enjoyed the video of changing the Volvo one in the watersmile

Works in the same way as a seal on a rotating shaft in your car (crankshaft, driveshafts etc), the seal lips facing towards the liquid you want to keep in (or in the case of that one, out!)
Interesting about the necessity to burp some of them incl the Volvo one, so may prove an irritation - with a risk of forgetting - if the boat is kept on a drying mooring.

Edited by paintman on Friday 29th July 09:00
You can avoid the necessity of burping by fitting an air vent pipe.

Simpo Two

85,422 posts

265 months

Saturday 30th July 2016
quotequote all
bazza white said:
Cheers seems I've been over thinking it. The diagrams above help. Jet drive would be great but may be over complicating it.

I'll have a million more questions for project mini boat.
If it's shaft drive you probably want the shaft going out through the hull/keel - transom would be too high and prop not deep enough. Uness you have a crazy design of course!

bazza white

Original Poster:

3,558 posts

128 months

Saturday 30th July 2016
quotequote all
Yes will be through the hull hence looking at jet drive easier to transport and store.

A small short shaft outboard maybe easier but where's the fun in that. Once Ive looked though gearbox\clutch options I'll know further.




paintman

7,687 posts

190 months

Sunday 31st July 2016
quotequote all
hidetheelephants said:
paintman said:
I enjoyed the video of changing the Volvo one in the watersmile

Works in the same way as a seal on a rotating shaft in your car (crankshaft, driveshafts etc), the seal lips facing towards the liquid you want to keep in (or in the case of that one, out!)
Interesting about the necessity to burp some of them incl the Volvo one, so may prove an irritation - with a risk of forgetting - if the boat is kept on a drying mooring.

Edited by paintman on Friday 29th July 09:00
You can avoid the necessity of burping by fitting an air vent pipe.
yes
Shown in several of the other options in Simpo's link. The volvo one doesn't have one fitted as standard & I'd be a bit dubious about bodging one into it.

hidetheelephants

24,357 posts

193 months

Sunday 31st July 2016
quotequote all
I've a vague idea there was a version of the volvo seal(or at least the same moulded-in-one style) with a stub for a vent pipe moulded into it.

paintman

7,687 posts

190 months