DrewHammer is asking great questions and his practical experience in what he does every day is invaluable. He is absolutely correct in his comment that there as many greases out there as there are people. What everyone needs to know is how to spec the proper lube for the application and read through the marketing B.S…
So as this is my first ever posting, I will refrain from being a an old gray hair Mech. Engineer windbag…I will try to bring some valuable info into this thread based on science, experience and no B.S.!
In my everyday job I am currently formulating very high performance greases and oils for specialty markets…for everything from fishing reels to off road heavy equipment. (I will respect this forum and not disclose our company’s name at this time or make a sales pitch…just info)…we have looked at and reverse engineered many lubricants that were marketed into the cycling, fishing, motorcycling and DIY markets…and yes, we have done the same with RC lubrication products. I will not disclose our findings, as I don’t want to generate a lawsuit or catfight…but we know who is who, and what is what as far as hype and actual performance of their products.
There are a few “good guy’s” out there and my hats off to them for doing a great job…but when you have access to a state of the art lubrication analysis lab and a spectral analysis system that can reverse engineer a lube product’s elements down to one part per million…you get some really interesting data.
I am currently working in complex “soaps” and nano-technology based lubricants which brings in a whole new science into lubrication products. But will still have to buy our grease oil bases, thickeners and additives from the same companies that the “big boy’s” do…and build our grease formulations one step at a time. And anyone who markets lubrication products can either build a product for performance or for profit…you would be surprised on what goes on out there. The performance oriented products usually are 3-4 time the cost, or more, than the “off the shelf” retail grease products.
I also have to deal with many people who don’t have any knowledge of grease formulations or what is a grease…so I have taken a bunch of time and put together a “grease primer” document…I have added it to this post….sorry for the length…but it helps dispel any wrong information early on. So getting to the meat of this thread…
1. A high percentage of greases available at retail in all markets are basically repackaged formulations of what is available from lubrication formulators…there is some customization of the base product additives and packaging is the real differentiator. You really have to be a majorly large company to “cook” and formulate your own grease in house…think Mobil. Texaco, etc.
2. A single batch of grease thickener or “soap” usually runs between 10,000 and 25,000 pounds per single batch…most of the “specialty” grease companies have to buy, including mine, have to have either a great relationship with the manufacture and be able to buy smaller amounts, or know someone in the business who has an excess in the warehouse they want to sell off.
3. Everyone in the lubrication business buys their oil base, “soap” and additives from the same suppliers…it’s all how you mix them together for the intended use is the differentiator.
4. Greases are dyed many different colors and in some cases fragrances are added to mask some really awfully smelling stuff…so color has nothing to do with performance, cost, intended use, etc…its just marketing.
5. Learn how to read the grease “recipe” info on the packaging and it will help you select the correct grease for your application. If its not there , don’t buy it!
Anyway, here is the grease primer that I give out…I take no credit as to its authorship as all of this info is out on the web if you know where to look for it.
The American Society for Testing and Materials (ASTM) defines lubricating grease as: "A solid to semifluid product of dispersion of a thickening agent in liquid lubricant. Other ingredients imparting special properties may be included" (ASTM D 288, Standard Definitions of Terms Relating to Petroleum).
Grease Anatomy
As this definition indicates, there are three components that form lubricating grease. These components are oil, thickener and additives. The base oil and additive package are the major components in grease formulations, and as such, exert considerable influence on the behavior of the grease. The thickener is often referred to as a sponge that holds the lubricant (base oil plus additives).
Base Oil
Most greases produced today use mineral oil as their fluid components. These mineral oil-based greases typically provide satisfactory performance in most industrial applications. In temperature extremes (low or high), a grease that utilizes a synthetic base oil will provide better stability.
Thickener (called "soap" in the industry)
The thickener is a material that, in combination with the selected lubricant, will produce the solid to semifluid structure. The primary type of thickener used in current grease is metallic soap. These soaps include lithium, aluminum, clay, polyurea, sodium and calcium. Lately, complex thickener-type greases are gaining popularity. They are being selected because of their high dropping points and excellent load-carrying abilities.
Complex greases are made by combining the conventional metallic soap with a complexing agent. The most widely used complex grease is lithium based. These are made with a combination of conventional lithium soap and a low- molecular-weight organic acid as the complexing agent.
Nonsoap thickeners are also gaining popularity in special applications such as high-temperature environments. Bentonite and silica aerogel are two examples of thickeners that do not melt at high temperatures. There is a misconception, however, that even though the thickener may be able to withstand the high temperatures, the base oil will oxidize quickly at elevated temperatures, thus requiring a frequent relube interval.
Additives
Additives can play several roles in lubricating grease. These primarily include enhancing the existing desirable properties, suppressing the existing undesirable properties, and imparting new properties. The most common additives are oxidation and rust inhibitors, extreme pressure, anti-wear, and friction-reducing agents.
In addition to these additives, boundary lubricants such as molybdenum disulfide (moly) or graphite may be suspended in the grease to reduce friction and wear without adverse chemical reactions to the metal surfaces during heavy loading and slow speeds.