What makes a grease a ~marine grade~ grease

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Is there certain features/specs that the marinegreade must meet at a minimum. Just short of it's resistance to mixing in water, is there anything else that sets it apart ?

I just purchased some $$ marine grade antisieze and was just curious...
 
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I do not think so,

I looked into this a bit a could not find anything,, it is a good question,,

So the best thing I can think of here is a Marine Grade stater motor has a addition little gasket on the cover for the arm that engages the bendix gear,, so no chance of spark,, or less chance

For this little gasket you will pay a additional 100 bucks,,,

Most good greases are tailored to resist or work well with water intrusion,,
 
following is the only spec i could find pertaining to a marine grade grease;
formulated with higher viscosity base oil to prevent water wash-out/ NLGI no.2
 
Water wash out..

Now this grease term I think is from what I have gathered focused on ,

Much like drop points, I mean do your really need a 900* rated grease for a wheel bearing??

Water wash out, pertains to where a grease is directly exposed to water,.,
IE a water pump bearing,

Now if your marine grade grease is going in a boat trailer wheel bearing,
Sealing, good quality seals, properly installed, keep the water out, #1 most critical,

aside from that amount of grease inside wheel hub, they say to much grease is no good, but the more something is filled up the less something can get in,
No two things can occupy the same space, so a happy medium of amount of grease, well sealed, are things to consider as well as what the lube is called
 
I would think these two below would be some of the most important specs to compare. I know some are saying that aluminum complex greases are better than the lithium for water applications.

Water Spray Off (ASTM D-4049), % max 8.5 NR*
Water Washout (ASTM D-1264) 80 °C [175°F] % loss 3.5 15 max




TYPICAL TECHNICAL PROPERTIES
AMSOIL Synthetic Lithium Complex Water Resistant Grease (GWR)


AMSOIL GWR


NLGI GC-LB
Thickener Lithium Complex NR*
NLGI Consistency Grade 2 NR*
NLGI Performance Grade GC-LB GC-LB
Extreme Pressure Fortified Yes NR*
Penetration (ASTM D-217) 25°C [77°F], 0.1 mm

Unworked
Worked 60 strokes



265-295
265-295


220-340
220-340
Dropping Point (ASTM D-2265) °C [°F] 273 [525] 220 [428]
Water Washout (ASTM D-1264) 80 °C [175°F] % loss 3.5 15 max
Oil Separation (ASTM D-1742) 24 hr. @ 25°C [77°F], % loss 1.0 6 max
Rust Protection (ASTM D-1743) pass 1 max
Timken OK Load Test (ASTM D-2509), lbs. 45 NR*
Four Ball Wear Test (ASTM D-2266) Wear Scar Diameter, mm 0.48 0.6 max
Compatibility with other greases excellent NR*
Extreme Pressure, Four Ball Method (ASTM D-2596)

Weld Point, kgf.
Load Wear Index, kgf.



315
42


200 min
30 min
Meets Disc Brake Wheel Bearing Specification:

GM 4733-M
GM 6031-M
Chrysler MS-3701



Yes
Yes
Yes


NR
NR
NR
High Temperature Life (ASTM D-3527) Hours 100 80 min
Fretting Wear (ASTM D-4170)* Mg 9.2 10 max
Leakage (ASTM D-4290), g* 1.0 10 max.
Low Temperature Torque (ASTM D-4693) n*m, max @ -40°C [-40°F] 7.5 15.5
Water Spray Off (ASTM D-4049), % max 8.5 NR*
*NR: Not Required for NLGI GC or LB labeling
 
I was looking for the right grease for our RV jacks. These are scissor jacks with a long threaded rod (about a foot and a half) that when cranked drops the jack down from the frame of the trailer to the ground.

These threaded rods (about an inch diameter) are open and exposed to water spray from the tow vehicle if it rains and normal rust from being outside all of the time.

Does marine grade grease seem to be the appropriate lube here? I can't seem to keep these ones lubricated.
 
Sorry to go off topic here,

Jim, I would think for that application a high solids brake caliper grease would work fine. They are designed to lube the sliding metal to metal, exposed to the weather brake parts. Because they are more "paste like", they might attract less dirt and grit also.

One product I can think of is Dow Molykote 77. Other options might be silicone brake caliper grease (extremely waterproof) or the Permatex Ceramic brake lube. Anti seize is pretty tenacious,corrosion inhibiting also and should provide enough lubrication properties for that application (just a hunch, based on no experience).
 
Originally Posted By: doitmyself
Sorry to go off topic here,

Jim, I would think for that application a high solids brake caliper grease would work fine. They are designed to lube the sliding metal to metal, exposed to the weather brake parts. Because they are more "paste like", they might attract less dirt and grit also.

One product I can think of is Dow Molykote 77. Other options might be silicone brake caliper grease (extremely waterproof) or the Permatex Ceramic brake lube. Anti seize is pretty tenacious,corrosion inhibiting also and should provide enough lubrication properties for that application (just a hunch, based on no experience).


To be fair, I'm the one who steered this thread off topic.

Thanks for the tip. I'll look at whether that would be economical. I've got the entire screw circumference on 4 jacks times 1.5' by 1" diameter to maintain here. If I can do it for $20 a season, I'll go for it.
 
Originally Posted By: oilboy123
I would think these two below would be some of the most important specs to compare. I know some are saying that aluminum complex greases are better than the lithium for water applications.

Water Spray Off (ASTM D-4049), % max 8.5 NR*
Water Washout (ASTM D-1264) 80 °C [175°F] % loss 3.5 15 max






Yikes! 8.5% for water spray off and 3.5% for water washout test??? You can get way better greases out there that have less than 1% washout in the same test, including the salt water soak test. Those are pretty bad numbers....
 
For non critical & convenience, I like "Corrosion Pro".
Industrial/Marine, Water resistance, Spray Grease.

I have a few cans from back in my boating days. Spray it on, it fizzles & bubbles a little then solidifies to a grease. Just used some last week on the Harley adjustable ball linkage joints. It gets in there so I don't have to take them apart. That's convenience to me, lazy to others.
 
Marine grade greases (quality ones) typically use Aluminum complex or Calcium Sulfonate thickeners as they are tougher than most other thickeners. The CS thickener actively helps to fight corrosion as well.
 
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