Which grease

[tudorsailor]

Naive question

Just had to change the impeller on the water pump (Yanmar engine). I used up the silicone grease that I had in a sachet from Speedseal and now would like to buy some more
Does it matter what I use on the spindle other than it being a silicone grease?

Do I need to buy from a marine store would something like this be acceptable

TS

 

[prv]

There's nothing special about it; I have a couple of tubes of this stuff for impellers and transducer O-rings.

Pete

 

[Topcat47]

I keep a small tub of Teflon grease on board. Small is the key word here as it's not cheap. I use it for this as it only takes a tiny smear. I've also used Vaseline. Don't be tempted to use ordinary waterproof grease though, as it cakes. Pushed, I might even try Blakes Seacock grease.

 

[Plum]

I keep a small tub of Teflon grease on board. Small is the key word here as it's not cheap. I use it for this as it only takes a tiny smear. I've also used Vaseline. Don't be tempted to use ordinary waterproof grease though, as it cakes. Pushed, I might even try Blakes Seacock grease.

I've also used Vaseline for many years on the impeller and splines with no problems. Whatever you use you only need a smear on the impeller as it is only there to aid assembly and to lubricate the initially dry impeller for the few seconds it takes for the water to get sucked through after which the water becomes the lubricant.

Colin. Www.solocoastalsailing.co.uk

 

[prv]

I'm always wary of using petroleum grease on rubber products. The contraption above used strips of bicycle inner tube to hold the ball in the socket (you can see one in the picture, but there are others round the back and more were added later) and I initially greased the joint with vaseline. After only a couple of days, all the rubber perished and snapped. I had to clean the grease off and fit new rubber strips, which then lasted for another week of vigorous use by groups of schoolchildren and were as good as new afterwards.

Of course there are lots of synthetic "rubbers" that are impervious to grease, and engine impellers are probably among them. But I still prefer to use silicone just in case.

Pete

 

[tudorsailor]

I was not really asking about how to lubricate the teeth but to lubricate the spindle so that I can get the impeller out next year

Thanks for all the replies

TS

 

[RichardS]

Like others above I use silicone grease for lots of rubber / plastic applications on the boat so last spring I have gave up with the small tubes and have bought a 500 gram tub off Amazon. http://www.amazon.co.uk/dp/B00KQ2T0CG/ref=sr_ph?ie=UTF8&qid=1445887155&sr=1&keywords=silicone+grease

Quite expensive at £16 odd but the cost per gram is much less that the tubes. I've filled a smaller container at home from the big tub so now I have enough to last me until next century at home and on the boat!

Richard

 

[rbmatthews]

I'm always wary of using petroleum grease on rubber products. The contraption above used strips of bicycle inner tube to hold the ball in the socket (you can see one in the picture, but there are others round the back and more were added later) and I initially greased the joint with vaseline. After only a couple of days, all the rubber perished and snapped. I had to clean the grease off and fit new rubber strips, which then lasted for another week of vigorous use by groups of schoolchildren and were as good as new afterwards.

Of course there are lots of synthetic "rubbers" that are impervious to grease, and engine impellers are probably among them. But I still prefer to use silicone just in case.

Pete

Nice to see JumbleDuck and his family giving you a hand!

 

[peteK]

I was not really asking about how to lubricate the teeth but to lubricate the spindle so that I can get the impeller out next
Thanks for all the replies
What ever you use it will have washed off when you want to get the impeller out.
TS

 

[ghostlymoron]

I use this for all boaty greasing. http://www.morrislubricantsonline.c...80/422/detailed/0/K99_500_GM.jpg?t=1433957561

 

[RichardS]

I use this for all boaty greasing. http://www.morrislubricantsonline.c...80/422/detailed/0/K99_500_GM.jpg?t=1433957561

Interesting. I've just bought 500g of water-resistant grease for rudder bearings and similar but I'm not sure whether it's suitable for synthetic rubbers and plastics, whereas I know that silicone grease definitely is. My tub of water-resistant grease specifies its uses but does not mention synthetic rubbers or plastics. Is your tub more revealing?

Richard

 

[tudorsailor]

Interesting. I've just bought 500g of water-resistant grease for rudder bearings and similar but I'm not sure whether it's suitable for synthetic rubbers and plastics, whereas I know that silicone grease definitely is. My tub of water-resistant grease specifies its uses but does not mention synthetic rubbers or plastics. Is your tub more revealing?

Richard

Here's the datasheet for the K99 grease

Seems that a silicone lubricant is best.

TS

 

[JumbleDuck]

Nice to see JumbleDuck and his family giving you a hand!

"Grease me up, Lunchlady PRV"

 

[Carmel2]

It's glyceride, isn't it? Cheep as chips from your local pharmacy.................

 

[vyv_cox]

Interesting. I've just bought 500g of water-resistant grease for rudder bearings and similar but I'm not sure whether it's suitable for synthetic rubbers and plastics, whereas I know that silicone grease definitely is. My tub of water-resistant grease specifies its uses but does not mention synthetic rubbers or plastics. Is your tub more revealing?

Richard

This chart http://www.quickcutgasket.com/pdf/Chemical-Resistance-Chart.pdf is a very comprehensive list showing the resistance of some elastomers to many chemicals. The ones with resistance to hydrocarbons are Viton (although there are many grades with their own particular properties) which is very resistant but usually too expensive for use in yacht products, Nitrile, which seawater pump impellers and various other common rubber bits are made from, and Neoprene, also quite widely used. Any of these is good with grease. Some domestic water pumps have EPDM valves and diaphragms, which is very poor indeed in oils, whereas bilge pumps usually have neoprene, which is good in hydrocarbons and water. Some can be specified with either EPDM or neoprene, so care is required.

edit: just noticed that it gives neoprene a D against grease and most oils. Quite surprising, as DuPont (its makers) describe it as oil-resistant, which was always my understanding.

 

[prv]

"Grease me up, Lunchlady PRV"

Just to be clear, the excited-looking chap in the picture above is not me. I made the wooden contraption and a mirror-image twin at his request; he provided the zebra-print rubber gloves and demanded their incorporation.

The small number of rubber ducks involved later inspired his purchase of much larger numbers for the Great Duck Caper...

Pete

 

[RichardS]

This chart http://www.quickcutgasket.com/pdf/Chemical-Resistance-Chart.pdf is a very comprehensive list showing the resistance of some elastomers to many chemicals. The ones with resistance to hydrocarbons are Viton (although there are many grades with their own particular properties) which is very resistant but usually too expensive for use in yacht products, Nitrile, which seawater pump impellers and various other common rubber bits are made from, and Neoprene, also quite widely used. Any of these is good with grease. Some domestic water pumps have EPDM valves and diaphragms, which is very poor indeed in oils, whereas bilge pumps usually have neoprene, which is good in hydrocarbons and water. Some can be specified with either EPDM or neoprene, so care is required.

edit: just noticed that it gives neoprene a D against grease and most oils. Quite surprising, as DuPont (its makers) describe it as oil-resistant, which was always my understanding.

The only use I can recall of Viton is for the rubber tip on the float needle of some carburettors I've worked on. As they spend the whole of their life immersed in petrol that resistance to hydrocarbons is pretty important! I think (although I'm not sure) that rubber O-rings and gaskets as usually neoprene so your post has convinced me to continue to use the silicone grease for this application, just to be on the safe side.

Thanks

Richard

 

[RichardS]

It's glyceride, isn't it? Cheep as chips from your local pharmacy.................

Nope, that's not silicone grease and I think that it's not very water-resistant so probably of limited value.

In fact, it might even be water soluble or that might be glycerol.

Richard

 

[davidej]

since we are on this subject

is ordinary water resistant grease (eg keenol) OK for a volvo shaft seal?

 

[RichardS]

since we are on this subject

is ordinary water resistant grease (eg keenol) OK for a volvo shaft seal?

I believe that Keenol is a lithium grease with a white anti-corrosion additive, usually called Marine Grease.

For the ultimate in water resistance you need one of the calcium based greases (I learned all this from Vyv). I'll bet that the special Volvo / Blakes etc grease is a calcium grease so it's probably worth buying a tub rather than paying exhorbitant prices.

Richard