What's new
What's new

Does synthetic oil and grease dry out and turn into varnish

Bill D

Diamond
Joined
Apr 1, 2004
Location
Modesto, CA USA
I understand silicone oil has no vapor pressure so it should never dry out. At least at machine tool gearbox conditions.
Do the synthetic oils and greases also not dry out over time. Or do they turn into varnish and gum up things over time. If I use a synthetic oil to lube a bearing bore before pressing it in will it be easier to press out in twenty years compared to a mineral oil which will dry up and glue it into place to some extent.
Bill D.
 
Everything has a vapor pressure. I don't know about 20 years, but the PAO based oils I use have never shown any tendency to thicken or turn into varnish. I'm guessing over time the stuff probably spreads out and disappears. If it's a grease, that might leave behind a solid glue of whatever the thickener/soap was. Silicone is a bad lubricant for metal on metal and probably not found in the lubes we use. Good for rubber though.
 
I understand silicone oil has no vapor pressure so it should never dry out. At least at machine tool gearbox conditions.
Do the synthetic oils and greases also not dry out over time. Or do they turn into varnish and gum up things over time. If I use a synthetic oil to lube a bearing bore before pressing it in will it be easier to press out in twenty years compared to a mineral oil which will dry up and glue it into place to some extent.
Bill D.

Comes to synthetics that depends on what the "designers" of it MEANT it to do, then whether it has even been in existence long enough to even know what 20 years might bring..

"Dry up" is not the proper explanation. Most vegetable oils polymerize, linseed and olive oils for example. Fewer mineral oils do that at "room" temperature, or at all.

Greases are a different horse. Cousin to "oil soaps", actually, and very often problematic off the back of that.

Most have an alkali involved as "sponge" for a lubrication oil, carried about, stuck to stuff, releasing and reabsorbing their oil component. Their "within spec" life span before degradation is only a few years, with Kluber's claim to fame due partly to being formulated for longer life than many others. Degrading into the adhesive role OTOH, takes far longer than simply falling out the bottom of their lube and load specs.

Castor oil is vegetable, was used in War One aero engines, and surely DOES throw poymerization "varnish" - it has been used as a vehicle for paints, much as linseed oil has. Even so, not so quickly it could not be used as an IC engine lubricant.

More often, mineral oils combine with air-borne dirt and/or trace chemicals, become food for bacteria, or cross-link / polymerize / oxidize from the influence of heat or age.

Johnson's "baby" oil is old-skewl "mineral" oil. Have yet to see it polymerize into any sort of "varnish" but then again, I've never tried to use it as lube oil in a hot and heavy Diesel engine.

Ignorant Vaseline has been used for parts assembly for ages. Mobil One might serve better?

Not sure I'll actually give a damn, 20 years out, but surely there is plenty of experience the past 100 years and more, already.

YMMV

:)
 
Story told to me by an old GE engineer that straight mineral oils would oxidize and gradually become thicker. I have seen the insides of old mills that the mineral oil had turned to hard cake. He said in the case of turbines, steam I would imagine, inhibited mineral oil was used. Inhibited meaning anti-oxidants. The discussion had to do with adding oil to pole faces of magnets to keep them quiet and rust free.


Tom
 
As for castor oil not being used in ic motors;in the 60's it was used in 2 strokes pre mix(total loss) and some sports car guys used it in their race cars but had to dump it every race.
One of the GM engineers that frequented our dealer ship after going to the SCCA races at Daytona heard about the sporty car guys using caster oil so he put some in the new Corvette demo he was driving.

The following week one of our mechanics asked me to look at the oil in a Corvette oil pan he had pulled off.It looked like gray play dough and felt like silicone rubber.I told him it smelled like Castor oil and asked him what car it came off.Bill's (the GM engineer) Corvette.
Apparently he missed the part about dumping it every race!
 
As for castor oil not being used in ic motors;in the 60's it was used in 2 strokes pre mix(total loss) and some sports car guys used it in their race cars but had to dump it every race.
One of the GM engineers that frequented our dealer ship after going to the SCCA races at Daytona heard about the sporty car guys using caster oil so he put some in the new Corvette demo he was driving.

The following week one of our mechanics asked me to look at the oil in a Corvette oil pan he had pulled off.It looked like gray play dough and felt like silicone rubber.I told him it smelled like Castor oil and asked him what car it came off.Bill's (the GM engineer) Corvette.
Apparently he missed the part about dumping it every race!

Prolly missed the part about it being toxic, even in the burnt fumes as well.
 
Or do they turn into varnish and gum up things over time.

I recall a auto supply store owner telling me that Pennzoil leaves a varnish type film on the inside of engines compared with other oils. I assumed that he was relating from his engine rebuild experiences. Not exactly the answer you are looking for but it does say that some oils are cleaner than others.
 
I recall a auto supply store owner telling me that Pennzoil leaves a varnish type film on the inside of engines compared with other oils. I assumed that he was relating from his engine rebuild experiences. Not exactly the answer you are looking for but it does say that some oils are cleaner than others.

I remember 40 some years ago buying Pennzoil at the local five and dime. The girl at the checkout counter told me her boyfriend warned her not to use Pennzoil because it turned to each after 20,000 miles.
 
All thats needed with castor oil is to read the warning s on the drum.........it doesnt like mineral oil,and mix the two and you ve got jelly.......a great many old engines and gearboxes have been saved by having castor in them........when water gets in ,the castor turns to a jelly that preserves steel parts........even crankcases that look like everything inside is badly rusted,the sludge comes off leaving clean steel.,,,,,,and you cant beat the smell of castor oil burnt in a speedway JAP motor running on methanol.
 
Castrol R is still readily available in several grades.......as for breathing the fumes,thats a good reason to be in front.......by the way...a JAP isnt a jappa,its English thru and thru....J.A Prestwich wss the maker ,of old London town.
 
Castrol R is still readily available in several grades.......as for breathing the fumes,thats a good reason to be in front.......by the way...a JAP isnt a jappa,its English thru and thru....J.A Prestwich wss the maker ,of old London town.

*I* knew who John Alfred was... A neighbour, Dad a GI, had brought one of his bikes back to Pennsyltucky around 1955. That, and a next-door Triumph "Bonneville", other mates who ran BSA. Matchless, Norton.. were great preparation for my adoption of a 1959 TR-3 4-wheeler some years later.

Well "four wheels. usually". TR's had the annoying habit of lunching undersized Timkens, the seizure snapping a spindle off at the upright, becoming a THREE wheeler. With sparks off the roadway, and oh, BTW, loss of all that Castrol Crimson Girling fluid and - needless to say - not only the mating Lockheed-Girling retarder, but the rears as well.

Thankfully, this was "in the plan" and one could sort of "row" to a halt with the clever 'fly off' handbrake.

No fear. It was only about $35 in those days for parts AND labour to install a new upright and spindle.

Septics had grown used to motor vehicles one simply put fuel and oil in, drove until the tires went flat.

Yah had to adapt to the British ethic of the era.

Nothing mechanical was meant to put the lads out of employment.

The usual drill was to tinker or tease at anything with wheels or heels all week. Then take yer enjoyment of a weekend, repeat the following week.

"Kit cars" we classed the MG's far more than the Triumphs.

Triumph Standard Motorcars had the wisdom to borrow a sturdy Canadian Massey-Ferguson 4-banger with Nickel-Iron wet liners & such. The SU's weren't bad. One balanced them by listening to the "hiss" at each throat via a length of radiator hose. Lucas electricals, OTOH? 'nuf said?

Also a pity they hadn't used more metal in the box frame so the front-end of it as oft impacted kerbs and such could keep both wheels pointing in the same general direction a bit longer even when NOT applying the retarders.

The Rudge-Whitworth's? Largest example of potato crisp curves about! TEDIOUS to get them true and tuned. WE were spoilt by Kelsey-Hayes or Standard Wheel making their wire-wheels with the cheat of WELDING the spokes at the factory. Go figure..

Morris Garages, by contrast, had apparently robbed a powered wheelbarrow maker's 4-banger instead, weren't much for getting out of their own road until they went to the Healey's six. Which was too heavy, of course.

Same again the first-generation AC, more garter snake than "Cobra", with a FOMOCO V8 as tended to splay the front wheels kinda spraddle-legged under mass not properly planned for.

Oy! The memories... young, poor, 2LT's meagre wage, only comfortable place to shag the loyal TR-3's resilient bonnet, warmed by that helpful tractor engine....

:)

But bikes.....roll-back about 60 years before J.A.P. had even set up at Tottenham. A bike from Nihon would have a name THEY understood.. NS, Asahi, and such.. given they had a thriving bicycle industry, also rickshaws, early-on, had, and had copied the "powered" US and European 2, 3, and 4 wheelers...

Japanese Motorcycles: the Early Days | The Vintagent

Another neigbbour, Air Corp brat, had the nicest sized of Japanese bicycles. It "just fit". Only later did I learn that generations of Japanese were far shorter than Americans. It was so nicely kitted-out because it was a luxury model for ADULTS, not a kid's push-bike at all!
 
I recall a auto supply store owner telling me that Pennzoil leaves a varnish type film on the inside of engines compared with other oils. I assumed that he was relating from his engine rebuild experiences. Not exactly the answer you are looking for but it does say that some oils are cleaner than others.
Around here, that warning was against "Quaker State" as their "hi paraffin content" tended to leave a milky white grease in the valve covers.
Easily seen by anyone removing the filler cap.


Pennzoil, made in the same general location* (with the same crude oil) didn't have those problems:
"Now with Z-7 !" probably was just a sales ploy
to get away from the Quaker state problems.

* IIRC the refinery maybe was all the same, I recall driving past Rouseville and seeing (3) tanks, one said "Pennzoil" the other "Wolfs Head" and maybe the third was "Quaker State" ?

I don't recall seeing a "Quaker State" refinery, unless it's the Bradford
refinery.
 
Back on topic i can tell you from exerience that good quality synthetic clock oil doesn't evaporate or oxidize at any noticable rate. I have a French clock that I overhauled 15 years ago & there is still visible oil on the pivots, so i imagine that it will last as long as the overhaul interval which is typically 20-25 years.
 
I remember conversations years back about paraffin base vs asphalt base motor oils, they seemed to go on forever…

I remembered I had some permatex super lube teflon grease at the shop & it really worked pretty good. The pics below are what’s left of the tube maybe 25-30 years old now & shrunk back a bit, but it still feels good??? YMMV

Good luck,
Matt
 

Attachments

  • Permatex_SuperLube1.jpg
    Permatex_SuperLube1.jpg
    78 KB · Views: 112
  • Permatex_SuperLube2.jpg
    Permatex_SuperLube2.jpg
    96.4 KB · Views: 89
I remember conversations years back about paraffin base vs asphalt base motor oils, they seemed to go on forever…
To be fair, they "mattered most" in the earliest days of petroleum extraction and the rather limited refining capability of those earliest days.

Before petro-chemists had found ways to make significant alterations to their raw feedstocks on an industrial and affordable scale that customers could actually afford to purchase, the crude DID matter.

Keep in mind that in-use, losses were also higher as fits were looser, seals were primitive - if even there WERE any seals. Small batch, practically laboratory hand-crafted lubricants, were not going to find a large market as, for example, John Steen's "Steen C" did in later years, or "Mobil One" has more recently.

"Pennsylvania Grade" crude oils were actually useful "right out of the ground" for many of the undemanding applications of the day. Most of the natural gas wells in the Appalachians yielded small amounts of Pennsylvania Grade crude's lighter fractions, sort of "distilled by nature" traveling up the bore with "casing head gasoline" - very nearly pure "octane".

The gasoline, paraffin fraction oil, and some of the other gasesous components (propane, butane, etc) and water were retained or separated out at the wellheads from the most-marketable methane.

"At the wellhead" because all of these were contaminants - some also corrosive as the water was from salt brine - to the collecting pipelines and pumping system leading to further processing and distribution.

Our two adjacent family farms had a total of five producing gas wells when Dad finally had to sell-up from old age and declining health and move into town. We had had at least one well plus a transit pipeline since purchase, 1912.

We owned the mineral rights, got free gas for the farm, 1/8th of the sales price, and "help yourself" to the separated contaminants - that much less for the gas company to collect and haul away.

"Casing head gasoline" had powered my late Uncle's dirt-tract Fronty-Ford racers, 1920's, but also our lawn mower, the maytag gasolinepowerd wringer washer operated outdoors, and tractors - model T derived to Farmall "Cub".

It was "free", after all.

G'Dad had used the raw crude oil fractions to lubricate primitive stationary engines, burn brush, kill weeds, preserve wooden fence posts, kill parasites, and more. Much of it - nearly ALL of it, as we NOW know - was environmentally unsound.

But what did we know of such things, a hundred years and sparse population density ago? Not much at all until Dad undertook organic Chemistry courses, Marshall College, 1926 (age 16) onward.

In the fullness of time, environmental rules had gradually tightened, causing the gas companies to seal-off those collected contaminants from local access, and haul all of them away far more carefully for safer eventual handling.

This was a "good thing", as their use had been careless out of ignorance, indifference, and that they were "free" and in apparently unlimited amounts.

Over a hundred years had gone by since "Oil City" Pennsylvania saw the start of it. Chemistry, volume, and "magic" of refineries had moved techniques from test-tube of a research lab to gadzillions of tons or barrels of many thousands of petro-derived products, fuels to structural material to medicines.

And here we are, where different flavours of crude oil, "sweet", sour", high and low ash, etc - each oil field's product as distinctive as DNA - still DO have an effect as to what their most economic fractionation fits - paving materials to motor fuels to feedstocks for plastics.

2 quarts, three generations, and 117 years worth
 








 
Back
Top