Greases with corrosion inhibitors, Solid lubricants and EP additives, salt water resistant, Semifluid?

[Alexnharvey]

Hello,

I am looking for grease that will provide good lubrication and corrosion inhibition in a ball bearing that is rubber sealed but nonetheless somewhat exposed to rain and gritty salt water which is sprayed at it and can sometimes pool around it. The bearing is relatively slow moving at about 50-200rpm and is also subject to shocks. For that reason I was thinking about a grease that is relatively fluid in use and that has a high base weight oil so that it provides a good oil layer at low speed and also keeps the seals wetted. Nonetheless I am assuming that some salt water will eventually make it past the seal and would like the corrosion inhibitors to protect the bearings for a period when this happens until they can be overhauled. The bearing does not have a grease port so I can't just purge the grease periodically, the unit has to be stripped down to allow regreasing unfortunately.

I've been suggested to look at greases like SHC1500PM which is for paper mill equipment. I suppose that some marine/agricultural/mining greases might also fit? I am finding it difficult to determine which grease have lots of corrosion inhibitors and which ones only have a little because lots of greases specify they contain some but never it seems the relative amount.
Can I rely on the ASTM salt water spray test or any other specifications?

 

[Snagglefoot]

Take a look at Shell Morlina products. They are Shell’s industrial marine line.

 

[Alexnharvey]

Thanks for your reply. Are there Morlina greases? I only see oils.

 

[RDMgr]

I would use a calcium sulfonate grease. They have exceptional rust inhibition, calcite, the thickening particles also act as EP/AS and anti-wear and they are lubricating solids. They also have a natural tackiness especially in heavier base oils and great water washout and spray off resistance.

The Shell Morlina is a range of bearing and circulating oils.

 

[Alexnharvey]

Thank you. I should've mentioned I am currently using a calcium sulfonate thickened grease with molybdenum disulfide and I think a modified petroleum base oil, LPS thermaplex CS moly bearing grease.

I liked the look of CAM2 ultra580 ep moly but there's no distribution in my region, the UK.

 

[ABN_CBT_ENGR]

Hello, I am looking for grease that will provide good lubrication and corrosion inhibition in a ball bearing that is rubber sealed but nonetheless somewhat exposed to rain and gritty salt water which is sprayed at it and can sometimes pool around it. The bearing is relatively slow moving at about 50-200rpm and is also subject to shocks. For that reason I was thinking about a grease that is relatively fluid in use and that has a high base weight oil so that it provides a good oil layer at low speed and also keeps the seals wetted. Nonetheless I am assuming that some salt water will eventually make it past the seal and would like the corrosion inhibitors to protect the bearings for a period when this happens until they can be overhauled. The bearing does not have a grease port so I can't just purge the grease periodically, the unit has to be stripped down to allow regreasing unfortunately. I've been suggested to look at greases like SHC1500PM which is for paper mill equipment. I suppose that some marine/agricultural/mining greases might also fit? I am finding it difficult to determine which grease have lots of corrosion inhibitors and which ones only have a little because lots of greases specify they contain some but never it seems the relative amount. Can I rely on the ASTM salt water spray test or any other specifications?

"Sealed" of shielded? (not the same thing)

Corrosion inhibitors and other additives will in no way protect the bearing or anything else from actual liquid salt water as it gets mechanically churned by the bearing with the grease for any significant amount of time.

What do you mean specifically by "sealed wetted"?

How do you re-lubricate this bearing? ( you say its sealed with no lube provision but you are wanting a grease- do you intend to manually pack before installation?)

What is the full bearing number ( and manufacturer) and what is the application?

 

[bruce381]

"I would use a calcium sulfonate grease." this the classic answer years would be soda grease but not many made anymore.

 

[Alexnharvey]

There are two types of bearings available for this application, sealed cartridges, normally 6000/6001 rubber shielded (sealed?), or manually adjusted angular cup and cone baallbearings, normally also rubber sealed.

I am manually packing the bearings with better grease, about 75% fill for the cartridges. Unfortunately the standard fills of most bearings are not adequate for the purpose. Because there is a cavity between the two bearings sometimes I rejoice the inner seal and fill the cavity with grease.

The application is top secret, I may have said too much already...

Seriously though, I've found if I say what it is at the outset I tend to get responses along the lines of "any old grease is sufficient for that application" which may be true but I want to find what the ideal is.

When I say keeping seals 'wetted' I mean that there is oil present at the seal contact point, preventing premature seal wear and helping prevent water ingress. I'd prefer the grease to 'weep' a little or be highly thixotropic to achieve this even if the seal leaks a bit of oil.

So, which calcium sulfonate greases have additional corrosion inhibitors and EP (beyond the thickener's inherent properties), a bit of solid lubricant and high weight synthetic bases?

 

[Snagglefoot]

Thanks for your reply. Are there Morlina greases? I only see oils.

Actually, it’s the Shell Gadus line I was thinking of. I picked Shell because the high probability of finding it in the UK. The Shell Gadus S2 V22OAD should work, or contact Shell UK.

 

[ABN_CBT_ENGR]

normally 6000/6001 rubber shielded (sealed?), or manually adjusted angular cup and cone baallbearings, normally also rubber sealed.

Is that ZZ, RS,2RS and are there any other characters? (manufacturer of the bearing would be helpful to see what its design load is) I presume this is a typical Conrad bearing with fixed 2 piece cage?

packing the bearings with better grease, about 75% fill for the cartridges.

For your RPM, go to 100% fill at all times.

When I say keeping seals 'wetted' I mean that there is oil present at the seal contact point, preventing premature seal wear and helping prevent water ingress. I'd prefer the grease to 'weep' a little or be highly thixotropic to achieve this even if the seal leaks a bit of oil.

You need not worry, that's going to happen. Thixotropic will be determined by a number of factors including the specific grease, any type of Couette activity/flow, temp, load, saturation, vibration etc. What you need to focus on is keeping fresh non spent grease in there given such a low RPM

The application is top secret, I may have said too much already...

Spare me the James Blonde stuff, not interested in the machine or what it does or what it makes- just the bearing housing and shaft. Its no secret it holds a bearing and turns in a circle. That's what you are asking about and we are talking about.

Seriously though, I've found if I say what it is at the outset I tend to get responses along the lines of "any old grease is sufficient for that application" which may be true but I want to find what the ideal is.

That "ideal" is why I'm asking the questions I am. Theres more to spec'ing a grease than a manufacturers brochure and a web search.

So, which calcium sulfonate greases have additional corrosion inhibitors and EP (beyond the thickener's inherent properties), a bit of solid lubricant and high weight synthetic bases?

As stated earlier, no additive package or recipe known to exist will protect for any significant length of time against liquid ingress into a sealed bearing when it gets trapped and mechanically blended with the grease.

 

[RDMgr]

"Corrosion inhibitors and other additives will in no way protect the bearing or anything else from actual liquid salt water as it gets mechanically churned by the bearing with the grease for any significant amount of time."

This isn't true. I've made aluminum complex and calcium sulfonates greases that passed the D6138 EMCOR test with a rating of 0. 0 using both synthetic and natural seawater. This is a dynamic rust test in which the bearing sits and rotates in the water. Test duration is 164 hours.

 

[ABN_CBT_ENGR]

"Corrosion inhibitors and other additives will in no way protect the bearing or anything else from actual liquid salt water as it gets mechanically churned by the bearing with the grease for any significant amount of time."

This isn't true. I've made aluminum complex and calcium sulfonates greases that passed the D6138 EMCOR test with a rating of 0. 0 using both synthetic and natural seawater. This is a dynamic rust test in which the bearing sits and rotates in the water. Test duration is 164 hours.

It most certainly is correct ( notice the "significant amount of time" part) Don't quote me a magic mix that passes a test for what amounts to a week of running in a non loaded test environment as if it means something because it doesn't. I know the test as well as the reality of the component as well.

I have literally examined thousands of bearings and grease samples that clearly and completely show the opposite in the REAL WORLD.

You mechanically churn grease ( or oil for that matter) and add other factors like load and heat, it WILL break down and mix. You have a little bit of time depending on specifics. "Rust' has nothing to do with it.( not to mention that alloy steels that are finished and hardened have a degree more resiliency for "rust")

This is another example of a mis-matched claim about a test that has no bearing on the real world.

Give me the name of this "grease' that is so hydrophobic that no matter the mixing schema with a liquid that it wont break down and eventually emulsify- I would like to evaluate it.

Thanks.

 

[bruce381]

any grease will have limits it sounds like I would just put a exsternal lube line to the bearings and give them a shot of grease on a timer or manually to keep 100% full and push out any ingress.

 

[RDMgr]

I can't give the names of these greases. I did this work for a company that I recently left. I am now working for a competitor and have non-disclosure and non-compete restrictions. I too have a lot of experience, nearly 45-years of experience in lubricant R&D and technical support and service, FMEA/FMECA and RCA including failure analysis of bearings and gears. More than 35-years of it was in developing and applying lubricants for the cement and mining industries...walking draglines, rope shovels, hydraulic excavators, ultra class haul trucks, mobile equipment, ball mills, SAG mills, kilns, etc. Lubricant design starts with application details and a portfolio of pertinent tests to demonstrate capabilities and performance.

In the OP's application, EMCOR testing would be an important consideration. Regarding your comments and concerns about temperature, the OP didn't mention that temperature was a concern. Of the greases that I developed or participated in the development of, one grease for military use on submarines. A second is manufactured for a marine OEM that manufactures and sells equipment to both recreational and commercial markets. A third is commercialized and used in the powersports market. The forth was interesting. It was an aluminum complex wheel bearing grease developed for several low lying coastal towns that experienced frequent floods with seawater and standing seawater in the roads. They had a very high number of wheel bearing failures on fleets of school buses and public works equipment. The problem was eliminated with a correctly formulated grease.

Re: Hydrophobicity-it makes for good sealing but not necessarily good corrosion inhibition.

 

[ABN_CBT_ENGR]

I can't give the names of these greases. I did this work for a company that I recently left. I am now working for a competitor and have non-disclosure and non-compete restrictions. I too have a lot of experience, nearly 45-years of experience in lubricant R&D and technical support and service, FMEA/FMECA and RCA including failure analysis of bearings and gears. More than 35-years of it was in developing and applying lubricants for the cement and mining industries...walking draglines, rope shovels, hydraulic excavators, ultra class haul trucks, mobile equipment, ball mills, SAG mills, kilns, etc. Lubricant design starts with application details and a portfolio of pertinent tests to demonstrate capabilities and performance.

In the OP's application, EMCOR testing would be an important consideration. Regarding your comments and concerns about temperature, the OP didn't mention that temperature was a concern. Of the greases that I developed or participated in the development of, one grease for military use on submarines. A second is manufactured for a marine OEM that manufactures and sells equipment to both recreational and commercial markets. A third is commercialized and used in the powersports market. The forth was interesting. It was an aluminum complex wheel bearing grease developed for several low lying coastal towns that experienced frequent floods with seawater and standing seawater in the roads. They had a very high number of wheel bearing failures on fleets of school buses and public works equipment. The problem was eliminated with a correctly formulated grease.

Re: Hydrophobicity-it makes for good sealing but not necessarily good corrosion inhibition.

I respect your creds but all that to say what exactly? You basically repackaged everything I said. You know exactly what I said and meant and the context it was posted in.

I said I know the EMCOR test (SKF designed it and I have my own little set up) and yes it would play a part (don't recall saying anything about it not) but go read the rest of it in context. Also go back about the limitations of the test I pointed out.

That being said, the OP has yet to make all the pertinent conditions required for a proper recommendation to be made known ( which is part of what I asked also because theres a difference between saturation/loading and spray then not only corrosion but overall lubrication)

Lets see what else he offers to fine tune any recommendations ( if any)

 

[Alexnharvey]

The bearing sees mostly salt water spray from road gritting. Full submersion would be very rare. Water ingress is not a given. If the seals are in good condition and are kept lubricated I think it may be mostly prevented but in the worst case will still pass the seals
Temperature is not an issue, given the low speed temperature will rarely rise much above ambient.
I will consider modification to add a grease port.

 

[ABN_CBT_ENGR]

The bearing sees mostly salt water spray from road gritting. Full submersion would be very rare. Water ingress is not a given. If the seals are in good condition and are kept lubricated I think it may be mostly prevented but in the worst case will still pass the seals
Temperature is not an issue, given the low speed temperature will rarely rise much above ambient.
I will consider modification to add a grease port.

Now it gets clearer. You have salt spray and potentially other chemicals as well as pulverized debris.

Remember, "sealed bearings" by design do not "seal" against liquids- they seal against particles. Moisture will wick and dynamically enter and once it, it will not ever leave.

Granted the scenario you present will be a slow damaging one (depending on the load on that slow RPM bearing- both axial and radial)

What about the housing this bearing sits in? ( you reference adding a grease port). I would investigate modifying that and if possible change the bearing to a W groove.

Is there anything you can do with the housing?

 

[Snagglefoot]

Shell Gadus 220 is getting talked about on two forums. Happened to see some today.

 

[Alexnharvey]

Hi,

The cartridge bearings are 2RS, normally specifying full or light contact seals. Normal clearance. Bearings are at each end of an axle. The mounting is aluminium and the bearings are pressed in. I've used a variety of bearing manufacturers, NTN, SKF, FAG.

Note that the axles are also supplied with a loose ball angular bearing arrangement rather than using sealed cartridge bearings. This arrangement is actually my preference because I think I think it handles the axial loads better.

In either sealed or loose bearing the housing can be drilled in the centre to add a grease port.

I have looked at the Shell |Gadus line. I can't find one that has solids, calcium thickener and a really high base weight oil, e.g. >460 rather than 220 but maybe that is nitpicking.

 

[ABN_CBT_ENGR]

a loose ball angular bearing arrangement

Lets get calibrated on language. What exactly are you describing? Are you saying you just have an open ( unshielded) bearing? Is this an angular contact bearing? ( not from the numbers you gave) What do you mean by arrangement? ( center faced, outward faced, both in, both out?)

Need to specifically clear that up

I think I think it handles the axial loads better

No ball bearing ( excluding an angular contact bearing) handles axial loads very well for very long. (intermittent are ok to a point)

Normal clearance.

I presume you mean C-5?

Bearings are at each end of an axle. The mounting is aluminium and the bearings are pressed in.

Now we are getting somewhere. Are they secured by any type of cap or retainer? Is there any type of seal ( lip or otherwise?)

In either sealed or loose bearing the housing can be drilled in the centre to add a grease port.

That's actually a very good idea and remove the inner seal to let the bearing purge but there are precautions depending on the answers to the rest of the questions posed.

Just curious, what type of failures have you already experienced or are you trying to be proactive or improve reliability of a current design?