Used (not engine) oil as bar lube

[OM617YOTA]

I never had chain stretch issues, even running canola oil.

 

[pdqdl]

Gear oil isn't thick. 75W90 is about the same viscosity as 10w30 motor oil, which is about the same viscosity as many bar oils.

"About the same" isn't exactly true.
Viscosity in oil is measured by what is called Kinematic viscosity. It is measured in centistokes (cSt) at 40°C (104°F) and 100°C (212°F).

Some relevant numbers for you to compare:

• SAE 0W-20 oil: 5.6-9.3 cSt at 100°C
• SAE 5W-30 oil: 9.3-12.5 cSt at 100°C
• SAE 10W-30 oil: 9.3-12.5 cSt at 100°C
• SAE 15W-40 oil: 12.5-16.3 cSt at 100°C

The typical viscosity range for 75W-90 gear oil is:

• At 40°C (104°F): 90-150 cSt
• At 100°C (212°F): 13.5-24.0 cSt

EDIT: Plenty of bad math has been deleted. This is what can happen when you don't cross reference your sources.

Now I have never looked into viscosity numbers like this before, so if anyone finds a mistake in my analysis, kindly let me know.

 

[J D]

For daily use cheap bar oil is what I stick to for a variety of reasons. One of which is it's lack of toxic additives. Another is the lack of toxic combustion by products like used motor oil has.

Agree regarding the combustion by products... its the toxic additives or any other "greeblies" that would be in the likes of gear or non combustion engine oil that I'm wondering about as adding them to bar oil seams like it would be a reasonable way to dispose of them in small quantities

 

[jblnut]

Gear oil isn't thick. 75W90 is about the same viscosity as 10w30 motor oil, which is about the same viscosity as many bar oils.

I guess I must remember that when posting on the internets one must remember everyone has a different view of things. We use a lot of 140w+ gear oil, even some 250w in certain things. That is considerably “thicker” than 10w-30 or 75w-90. We were mentally starting in different places. Gear oil is better suited for bar oil than engine oil as it’s made for applications where extreme pressure is more present than extreme heat thus it sticks to the bar better. Plus I like how it smells and no one ever grabs my bar oil jug so I don’t have to worry about it walking away lol.

 

[jblnut]

Agree regarding the combustion by products... its the toxic additives or any other "greeblies" that would be in the likes of gear or non combustion engine oil that I'm wondering about as adding them to bar oil seams like it would be a reasonable way to dispose of them in small quantities

Are you pondering about the different kind of things in oils getting into the ground or into the wood you’re cutting or getting into your body in some way ?

 

[J D]

Are you pondering about the different kind of things in oils getting into the ground or into the wood you’re cutting or getting into your body in some way ?

Anything adverse really... I'm all about making as informed a decision as practical

 

[pdqdl]

I guess I must remember that when posting on the internets one must remember everyone has a different view of things. We use a lot of 140w+ gear oil, even some 250w in certain things. That is considerably “thicker” than 10w-30 or 75w-90. We were mentally starting in different places. Gear oil is better suited for bar oil than engine oil as it’s made for applications where extreme pressure is more present than extreme heat thus it sticks to the bar better. Plus I like how it smells and no one ever grabs my bar oil jug so I don’t have to worry about it walking away lol.

Gear oil costs way too much. Unless you have a used gear oil supply.

 

[snobdds]

What is the base oil for bar and chain oil?

What about hydraulic fluid? I drain that stuff out of equipment that looks brand new.

 

[rogue60]

Guy's worrying about harmful effects if any of bar oil running a saw... Yet these same guy's ignorantly consume in their diet copious amounts of Canola oil daily

 

[jblnut]

Gear oil costs way too much. Unless you have a used gear oil supply.

Dozens of gallons of gear oil and hundreds of gallons of hydraulic fluid get changed on the farm each year so yes, I have a good used supply. Run it through a fine filter and pump into the used (good) oil tote. Between neighbors and I we’ll burn through 25-30 gal of bar oil a year and by no means use it all.

Once in a while I’ll get a couple of pails of oil from a local NAPA or Auto Value for $1/gal because it’s been on the shelf too long or was something that didn’t sell through or whatever. Depending on what it is I’ll run it through the saws or use it for its labeled purpose. I have a Ford Ranger that burns enough oil that it only gets a filter change every few years and gets whatever flavor of engine oil I have around as it won’t last long in there anyway. Haven’t “changed” oil in around 100k miles and it always looks clean on the stick lol.

 

[buzz sawyer]

Sounds like a chain sharpness issue. I say this because I have cut with stuff as light as two cycle oil with difference in the amount of tensioning required.

Nope, occurred with several chains, some newly sharpened - and they WERE sharp.

 

[bwalker]

Gear oil costs way too much. Unless you have a used gear oil supply.

And stinks like hell.

 

[scottr]

Was changing the oil in my gearbox the other day & it got me thinking... now I'm the first person to say used engine oil is a bad idea for bar lube for a number of reasons, but most of the reasons that come to mind for engine oil aren't (as far as I'm aware) nearly as relevant for the likes of gear oil (diff, gearbox, lathe, etc) or non combustion motors like compressors etc. Asides from the lack of tackifier, are there any significant reasons not to filter these & either add them in low ratio to regular bar oil or use them in the aux oiler for the mill?

There is a 14 month old video on youtube 'How to Make Cheap Chainsaw Bar Oil' that might be of interest .

 

[bwalker]

There is a 14 month old video on youtube 'How to Make Cheap Chainsaw Bar Oil' that might be of interest .

I bet that's a real gem. I'd rather have a tooth pulled..

 

[bwalker]

What is the base oil for bar and chain oil?

What about hydraulic fluid? I drain that stuff out of equipment that looks brand new.

Walt Galer, who was a former employee of Windsor claimed it was mostly reject hydraulic oil with paratach added. Paratach is PIB as blended in all JASO FD two cycle oils.
At any rate be assured it's not some high tech base stock.

 

[NSEric]

What is the base oil for bar and chain oil?

What about hydraulic fluid? I drain that stuff out of equipment that looks brand new.

Hydraulic oil is good bar oil but is a little messy without the additive to make it sticky.
Some harvesters use it as bar oil without issue so they dont need a different oil, they just pump it into the bar and know they have to top up the oil daily.

 

[bwalker]

Hydraulic oil is good bar oil but is a little messy without the additive to make it sticky.
Some harvesters use it as bar oil without issue so they dont need a different oil, they just pump it into the bar and know they have to top up the oil daily.

When logging it's always on hand so it's often used in a pinch.

 

[buzz sawyer]

Tractor Supply wants $15/gal for their County Line brand, $25/gal for Husqvarna brand. Of course, this is California where are petroleum products are off the wall...

https://www.ruralking.com/all-season-bar-and-chain-oil-1-gallon-80565-17431

 

[nedsim]

The cSt scale is logarithmic.

Where did you get this? As far as I know, the kinematic viscosity of a liquid in cSt is simply the time in seconds a measured sample of liquid takes to flow thru a calibrated orifice at a specific temperature.

 

[pdqdl]

Where did you get this? As far as I know, the kinematic viscosity of a liquid in cSt is simply the time in seconds a measured sample of liquid takes to flow thru a calibrated orifice at a specific temperature.

Not quite that simple, but let me confess that I didn't do enough checking, either. I should have checked my formulas with Wikipedia, which is quite detailed and complex.

I thought I was working off the kinesthetic viscosity, but ...mistakes were made. Let's just say that gear oil is just about always considerably "thicker" than motor oil.

Given your suggestion to quote my references, I have decided that I did it wrong.

EDIT: Plenty of bad math has been deleted. This is what can happen when you don't cross reference your sources.