Fergus
Well-Known Member
Is it OK to use standard automotive grease for this? I'm sure there is a vastly more expensive "specially designed for" type of grease but does it really matter?
Thanks for reading!
Thanks for reading!
Stern tube grease
- Thread starter Fergus
- Start date
StugeronSteve
Well-Known Member
Is this for a Volvo shaft seal? The Volvo waterproof felt grease is expensive for such a small tube, but not a lot of money. I have always used the Volvo stuff, just to be on the safe side, and the nozzled tube does make it easy to squirt the stuff in.
Fergus
Well-Known Member
No it's a Yanmar 2GM20
StugeronSteve
Well-Known Member
Is it the same principal, water lubricated rubber gaiter, that needs a squirt of grease after launching?
Fergus
Well-Known Member
It's one of the usual grease-filled tubes with a tap which need refilling from time to time
StugeronSteve
Well-Known Member
Sorry, can't help then.
S
Skyva_2
Guest
Fergus, you need a waterproof grease for a stuffing box which was Duckhams Keenol till they stopped making it! Am now on my last tin....
This link might be useful: Oil Store
or Norris Marine Isleworth and Sillete Sonic are reputed to still have it.
Search the board on 'keenol'
Anyone know of a good alternative?
This link might be useful: Oil Store
or Norris Marine Isleworth and Sillete Sonic are reputed to still have it.
Search the board on 'keenol'
Anyone know of a good alternative?
nedmin
Well-Known Member
when greasing the volvo seal you need to get the grease inside,I would recommend a polythene bag, cut the corner off put in about a cubic cm of grease, squeeze the seal on the outer circumference,thus making it oval, push the cut corner into the seal ,squeeze the grease in.
Fergus
Well-Known Member
I can't quite get my head around the notion of "waterproof grease" - what does this mean and how is it different from the usual petrochemical product?
Lakesailor
Well-Known Member
K Y Jelly is not waterproof, if that helps.
Robin
Well-Known Member
You need a waterproof grease such as is used for boat trailer bearings. Duckhams Keenol was the stuff but is no longer available. I bought some I think made by Morrisons from the automotive shop top of Quay Hill bottom of the High St in Lymington - and it wasn't expensive. The guy in the shop keeps it for yotties for stern tube use.
Ships_Cat
Well-Known Member
I can't get my head around it either. The general comment I see is that "waterproof" greases are somehow "special" in that they are lithium based, but as far as I know all common HP greases (ie as sold for automotive use) are lithium based and that is all I ever use for all purposes (including stern tube and winches - both areas where some say "waterproof" is mandatory).
John
John
Fergus
Well-Known Member
I found this for those who want something specifically designed for the job..http://www.shipshaperamsgate.co.uk/grease/aqua.html
I think I'll just use my £3.50 pot of normal stuff and try to find a non-messy way of getting it into the tube (already armed with chain wrench in case the top is stuck!)
I think I'll just use my £3.50 pot of normal stuff and try to find a non-messy way of getting it into the tube (already armed with chain wrench in case the top is stuck!)
PCUK
Well-Known Member
Don't use graphite grease. It's at the top of the galvanic scale and eats everything below.
brianhumber
Well-Known Member
Re: Greases
Have a lot of different applications and uses requiring different mixes.For example lifeboat wires which are mainly anti-corrosive with a little bit of sheave lubrication properties, steam recip winch grease which requires a sliding lubrication property with say a graphite base and underwater bearing grease which needs to stick as well as form a film boundary layer of lubrication to separate the two surfaces.
All applications will tend to work from a lubrication aspect which is why using a normal grease for underwater works for some but not as efficiently as the correct grease BUT any graphite will be damaging due to galvanic action on stainless shafts for example.
As an aside and an example of the fact you do not always have to follow convention, I never grease my 'Volvo' type stern seal, preferring to using the water film to get a boundary layer and keep the rubber lips off the shaft and thus cool. I get about half a cup of water for about 12hours running at 2,000 revs.
The seal is 19 years old and has many thousands of hours running time. This is just following big ship practice which went from sea water cooled packing in wooden bearings to water cooled tufnol bearing and seals to oil white metal bearing and lip seals and now water plastic bearings and lip seals in the latest cruise ships.
When I had older packing seals I let the seal drip when underway and the grease was just used to 'seal' the shaft when back on the mooring by half turn on the greaser.
Brian
Have a lot of different applications and uses requiring different mixes.For example lifeboat wires which are mainly anti-corrosive with a little bit of sheave lubrication properties, steam recip winch grease which requires a sliding lubrication property with say a graphite base and underwater bearing grease which needs to stick as well as form a film boundary layer of lubrication to separate the two surfaces.
All applications will tend to work from a lubrication aspect which is why using a normal grease for underwater works for some but not as efficiently as the correct grease BUT any graphite will be damaging due to galvanic action on stainless shafts for example.
As an aside and an example of the fact you do not always have to follow convention, I never grease my 'Volvo' type stern seal, preferring to using the water film to get a boundary layer and keep the rubber lips off the shaft and thus cool. I get about half a cup of water for about 12hours running at 2,000 revs.
The seal is 19 years old and has many thousands of hours running time. This is just following big ship practice which went from sea water cooled packing in wooden bearings to water cooled tufnol bearing and seals to oil white metal bearing and lip seals and now water plastic bearings and lip seals in the latest cruise ships.
When I had older packing seals I let the seal drip when underway and the grease was just used to 'seal' the shaft when back on the mooring by half turn on the greaser.
Brian
reeac
Well-Known Member
Re: Greases
Interesting that you never grease your Volvo-type stern gland. A while ago I quoted my marine engineering guru as saying just this but various forum people came back saying "ooh! you should grease it!". I haven't done so [apart from when first installing it] but it's early days as yet.
Interesting that you never grease your Volvo-type stern gland. A while ago I quoted my marine engineering guru as saying just this but various forum people came back saying "ooh! you should grease it!". I haven't done so [apart from when first installing it] but it's early days as yet.
brianhumber
Well-Known Member
Re: Greases
Yes it is convention to grease as I said and to be fair it is the manufacturer's recomendation. If all chambers between the lip seals are filled with grease then an annual grease replenish would be needed to set up the lubrication film or the lips press on the shaft, overheat and wear out in very short order. The key element is the formation of the boundary layer by what ever film. ( there are some very well documented cases of the latest cruise ships having problems in getting this right in their stern tube bearings) However oil seals are not without problems especially when they leak and again I have had to tip a ship so that the oil lubed stern tube and shaft seals were out of the water to change the seals in Tokyo Bay over Christmas. Very cold and quite expensive in antipolution measures. In my case on the Ronhilda as the grease has long gone it is water that is providing the film and I live with the very small ingress whenever the shaft is turning.
As a back stop I have ready made sealing clips and material should the seal finally 'give up' plus I can get access to the seal if needs be. Not everybodies installation is as good as mine for access and not everybody is an engineer so I can well understand other's strict compliance with annual greasing.
Yes it is convention to grease as I said and to be fair it is the manufacturer's recomendation. If all chambers between the lip seals are filled with grease then an annual grease replenish would be needed to set up the lubrication film or the lips press on the shaft, overheat and wear out in very short order. The key element is the formation of the boundary layer by what ever film. ( there are some very well documented cases of the latest cruise ships having problems in getting this right in their stern tube bearings) However oil seals are not without problems especially when they leak and again I have had to tip a ship so that the oil lubed stern tube and shaft seals were out of the water to change the seals in Tokyo Bay over Christmas. Very cold and quite expensive in antipolution measures. In my case on the Ronhilda as the grease has long gone it is water that is providing the film and I live with the very small ingress whenever the shaft is turning.
As a back stop I have ready made sealing clips and material should the seal finally 'give up' plus I can get access to the seal if needs be. Not everybodies installation is as good as mine for access and not everybody is an engineer so I can well understand other's strict compliance with annual greasing.
neale
Well-Known Member
Ramonol, supplied by Oil Store is a direct replacement for Duckhams Keenol.
Neale
Neale