Oil and alcohol don't mix?!

[SecondMonkey]

So I was pouring my usual dose of 2 cycle oil into my truck, because I like to use it as an UCL. Normally when I'm done, I rinse out the leftover oil in my beaker with gas and dump that in the tank too.

Today I didn't have any gas, so I used a a few ounces of 99% isopropyl alcohol. Much to my amazement, the oil and alcohol did not mix! The oil sank to the bottom and when I stired it up it stayed in little globules as if I was mixing with water.

What's with that? Do isopropyl alcohol and oil not mix?! Is there something wrong with the bottle of oil I'm using? (it's been open for about a year, just trying to get rid of it) Even if there was water involved somehow, the alcohol should have made it all mix.

 

[FowVay]

Alcohol is a kissing cousin of water (same family) so it stands to reason that it doesn't mix with oil.

Ever wonder why alcohol takes water out of fuel? CH3-CH2-OH will attach nicely to HOH (example only).

 

[labman]

My guess is that it should have washed the oil out. Guesses are often wrong. I checked my CRC handbook. It says isopropyl alcohol is miscible with diethyl ether, which is only slighly more polar than oil. That is for the pure materials. The more water in it, the less oil will dissolve in it. If your alcohol set around opened, it could have adsorbed too much water to cut the oil. Other polar materials adsorb water just like brake fluid.

Are you sure it was 99 %? Usually what I find is 35%.

 

[Pablo]

This is one of the reasons, along with the hygroscopic nature of alcohol, that many two strokers are not in love EtOH fuel. No they don't mix so well as you found out.

I tried mixing some methanol based fuel scent with two stroke oil, same problem. Two distinct phases. Just add a tiny amount of modern gasoline and BAM, everything is soluble. Part of the additive package in 10% EtOH fuel are co-solvents and such that bring everything into solution, to a point.

 

[ryan2022]

good to know!

I thought this was going to be a "had too much to drink and tried to do an oil change" story!

 

[mechtech2]

So you intended to put something that is 1% water in your gas tank?

I know that 2 stroke oil and normal ethanol /gas mix well.

 

[PandaBear]

Originally Posted By: ryan2022
good to know!

I thought this was going to be a "had too much to drink and tried to do an oil change" story!


I was thinking beer and french fries related health problem

 

[SecondMonkey]

Originally Posted By: mechtech2
So you intended to put something that is 1% water in your gas tank?

Yep. I've poured bottles of 91% isopropyl in there many times before. I'm just surprised that I've never actually tried mixing alcohol and oil before.

I have several gallons of pure lab grade isopropyl that I'm going to use up in my tank eventually.

That 1% water in about 4 ounces of alcohol mixed with 15 gallons of gas is probably less water than comes from the pump at Chevron.

 

[AcuraTech]

Alcohol (the consumable kind) and oil (forums) don't mix! After catching a buzz and logging onto BITOG, I'm always about ready to incite a riot.

Rumor has it that after enough beers you become smarter than an encyclopedia and strong enough to stop a standing army. Wouldn't know anything about that though.

 

[mechtech2]

Water in fuel in almost non existent , nowadays.
Even if it was in the underground tank, the final filtering stops it.

 

[SecondMonkey]

Originally Posted By: mechtech2
Water in fuel in almost non existent , nowadays.
Even if it was in the underground tank, the final filtering stops it.


Is the ethanol they use 100.00000% pure? I don't know, but I'd be willing to bet it's closer to 99%.

Regardless, a vehicle will run fine with several percentage points of water in the alcohol...

 

[andyd]

My brother manages the repair facilities for a civil engineering outfit in VT. When the fuel supplier switched to 10 % ethanol gas, the gas powered equipment went down in short order. Turns out the ethanol was coming out of solution in the storage tanks. Once they went back to pure gas, the problems disappeared.

 

[Samilcar]

Originally Posted By: mechtech2
So you intended to put something that is 1% water in your gas tank?

I know that 2 stroke oil and normal ethanol /gas mix well.


The anhydrous ethanol that is blended in to gasoline to make E10 is normally 1% water. Hydrous ethanol (like is used for E100 motor fuels in Brazil) is 4% to 7% water.

 

[L_Sludger]

Here I was thinking that this was an ominous safety message brought to you by an inebriated oil change that ended in tears.

 

[tom slick]

On the original topic; it depends on the oil. The USAF uses denatured alcohol for cleaning everything around a jet engine. The hydraulic fluid and engine oil (both synthetic) would bead up like you describe when hit with alcohol. Regular non-syn automotive engine would not bead up and the alcohol wasn't a very good solvent for it if you had quite a bit to clean up.