Is using grease that's 25 years old ok?

[Slioch]

Gawd I must be bored posting this!

I'd removed my pedals to give them a clean, and reached for my trusty pot of waterproof grease to put a dab onto the threads before screwing them back in, which got me thinking. The pot of grease must be 25 years old at least, probably even older.

It's gone a bit yellow over time and maybe a bit stiffer than when new, but I still use it to regrease bearings and other moving parts, as well as putting it on the threads of things that screw in, with no noticeable ill effect.

So the question is, does grease have a best by date, and should I consider investing in something a bit more modern? (If so, can you provide recommendations please?).

Here's a couple of the most exciting pics you are likely to see on t'internet today...

TIA

 

[Deleted member 26715]

I would, but I'm sure some boffin will be along to advise why you shouldn't

 

[Smudge]

I'm still using grease older than that. It must be 30+ years old.
I dont believe it goes off.

 

[I like Skol]

It spends millions of years underground so I guess a decade or two longer won't make much difference.

 

[Yellow Saddle]

It is good to go, just don't believe the waterproof nonsense.

 

[MontyVeda]

I'm still using a tub of grease I bought from Wilko in the early 90s... I knew at the time it'd last me a lifetime

 

[roley poley]

if you get new don't mix lithium (white)grease with brown as they turn into a sludgy lumpy mess

 

[PK99]

I suppose so, if it's the one that you want.

 

[Andrew1971]

It looks like smooth peanut butter. Try it just to see !!!

 

[Specialeyes]

I suppose so, if it's the one that you want.

...or if you're hopelessly devoted to it.

 

[figbat]

I would, but I'm sure some boffin will be along to advise why you shouldn't

You called? In truth I am not specifically a grease boffin, but I am a lubricant and lubrication boffin of 27+ years. Greases are quite specialised (and not my forté) but in general terms are an oil with a thickener added. Over time they can separate, leaving an oily layer on top. If this hasn't happened the chances are it's good to go. I wouldn't grease a safety-critical system with it, but I can't see a problem with general bearing use.

It spends millions of years underground so I guess a decade or two longer won't make much difference.

The raw materials may have been underground for a while (at high pressure and temperature), but it's when you extract, refine, process and recombine them in different ways that their stability can be upset. And it isn't all from crude oil either - there are metals in there which have been mined and processed (zinc, calcium, lithium, molybdenum etc).

 

[Bazzer]

As with some others on this thread, I have some in my garage which is >25 years old. It still looks and feels like it did when bought.

 

[Deleted member 26715]

You called? In truth I am not specifically a grease boffin, but I am a lubricant and lubrication boffin of 27+ years.

My old neighbour used to used to be into oil, think it was Comma he worked for, he could put a bit of oil between his fingers & basically tell you what it was & what was in it from it's texture & smell, or he at least he could, no way to disprove it.

 

[PpPete]

...or if you're hopelessly devoted to it.

boom - tish

Your coat is just over there....

 

[Soltydog]

I have a tin of bearing grease that i borrowed from work back in the 90s, maybe I should return it at some point