stern gland grease!

[co256]

any recommendations for the best brand/type out there???

my boat came with a tin of lithium grease and it's definitely what's in the greaser but I'd like to hear some informed opinion.

many thanks!

 

[CAPTAIN FANTASTIC]

I fill the stern tube with waterproof grease, the white staff; it works well.

 

[Skysail]

The white grease is Ramonol, which is the equivalent of Keenol.

 

[oldsaltoz]

The white grease is Ramonol, which is the equivalent of Keenol.

Is this the same as cannery grease?

 

[Skysail]

Sorry, cannery is a new name to me!

 

[Rowana]

The white grease is Ramonol, which is the equivalent of Keenol.

That's wot I use.

 

[oldsaltoz]

Sorry, cannery is a new name to me!

It's water resistant grease used on machinery in factories the put food into cans.

 

[alahol2]

White waterproof here too.

 

[co256]

sounds like the stuff I have!

MPG, made by Rock Oil, it's a white lithium grease.

Thanks for all your help!

 

[VicS]

From Rock Oil's website

Rock Oil MPG is a multi-purpose lithium based grease containing
zinc oxide additive to repel moisture making it particularly suitable for
use in marine outboard and inboard engines. It's thermally sensitive
construction makes it ideal for use in boat trailer hubs and stern
tubes.​

 

[alahol2]

From Rock Oil's website

It's thermally sensitive
construction makes it ideal for use in boat trailer hubs and stern
tubes.​

What does that mean? Surely a sterntube isn't going to change temperature enough to affect a grease.

 

[co256]

Thanks VicS,

I should have done more research before bothering the forum!

The issue of grease in a stern tube seems to be quite contentious!!!

As I understand it.... water in the stern tube is necessary for cooling, too much and we have a leaky boat, no water at all and we overheat the stern gland, add grease to the mix and we risk further overheating (because grease is a poor conductor) and therefore damage to the stern gland packing!

To the point that some (possibly vyv cox) don't appear to advocate using grease at all?!

I might be mis-representing vyv here so don't take my word for it, if I have please correct me and apologies to vyv!

Guy.

 

[vyv_cox]

Thanks VicS,

I should have done more research before bothering the forum!

The issue of grease in a stern tube seems to be quite contentious!!!

As I understand it.... water in the stern tube is necessary for cooling, too much and we have a leaky boat, no water at all and we overheat the stern gland, add grease to the mix and we risk further overheating (because grease is a poor conductor) and therefore damage to the stern gland packing!

To the point that some (possibly vyv cox) don't appear to advocate using grease at all?!

I might be mis-representing vyv here so don't take my word for it, if I have please correct me and apologies to vyv!

Guy.

We have had a discussion on the design of stern gland packings in the past few weeks. Search 'lantern ring' to find it. My impression is that in the vast majority of cases the grease does not go into the packing rings at all, only astern of them. Here it may possibly be forced by differential pressure back into the packing but when I stripped mine I found no evidence of this. There was a large mass of grease in the stern tube but none that I could see in the packing itself. This despite the fact that my packing was as old as my ownership of the boat, about 12 years at the time, never changed, nipped up once or twice, and never leaked a drop.

Ordinary lithium-based grease is perfectly OK for a stern gland, if you must grease it. I inherited a tin of Esso automotive grease when I bought the boat and used it until it ran out. I then bought a tub of the cheapest stuff I could find from my local car parts shop. That's the stuff that was in the stern tube when I changed the gland out for a PSS. Lithium grease is pretty waterproof and most unlikely to suffer at the low speeds we are talking about. I also use it in my seacocks, where it lasts a season perfectly well.

 

[ianat182]

Sterngland grease

I believe that the most recent type of sterngland packing is PTFE impregnated for its non friction properties, and PTFE is probably the best material there is for friction free use in solid form i.e.(ice on ice).
If this is so ,then any other grease is basically for the water control and the cutlass bearing lubrication in some instances, just that it needs the waterproof specification to prevent being washed away. IMHO of course.

ianat182

 

[co256]

Thanks to vyv and ianat,

out.