Removing ethanol

[pallis]

I've had this idea about putting a valve on the bottom of a gas can that will allow me to drain the alcohol and water out of the bottom, and then add an octane booster to the gas.   Has anyone tried this? 

[John R]

Does gasoline and ethanol separate?

[pallis]

Does gasoline and ethanol separate?

Ethanol loves water, as in moisture in the air, and it will leave gas behind like an ugly girlfriend when water comes along.  Seems to me the problem gets a little worse when the gas is mixed with oil.  ...I use synthetic at 32/1. 

These days I don't get more gas than what I figure to use in my saws in a couple of days, but this thought has been  bouncing around in my head.  Today I had to empty the gas tank on a small loader/backhoe.  The gas had been sitting for awhile, and had water in the bottom of the tank.  I don't know if the alcohol caused it, but that is my guess.

[John Mc]

Gas and ethanol will separate if you add water, shake very well, and let it sit for a while. You could then drain off the ethanol/water mix from the bottom. Best to do this before you add stabilizer or mix oil. There may still be a bot of ethanol or water in the gas, but it will be slight (the colder the gas, the less water it will hold)

Note that E10 gas (gas with ethanol) gets about 4 of it's octane rating from the ethanol. If you start with premium E10 (93 Octane) you'll ed up with about 89 Octane... probably still OK for most stock chainsaws. If you start with 87 (regular) or 89 (mid-grade), you've got a problem when you take the ethanol out. You'll end up with about 83 or 85 octane - not good for a chainsaw (or a lot of other engines)

You can add octane boosters, but there are two things to consider with this. The labeling on some octane boosters is a bit misleading. When some of the labels say "adds two points of octane" what they mean is 0.2, not 2.0. Also, some octane boosters are mainly alcohol of one form or another, so you are just adding the problem back in when you add them.

John Mc

[Magicman]

And then you can check the alcohol/ethanol content with this:

https://forestryforum.com/board/index.php/topic,45394.0.html

[sharkey]

Do you have an automobile or motorcycle race track in your area?  The ones here sell high test unleaded gasoline without alcohol.  As an alternative, you can stop by your local small airport and buy low lead airplane gasoline for a dollar more a gallon.  Turbo Blue is one of the names that comes to mind at the drag strip.  There is also a 260 Sunoco offered at one of the other tracks.       

[John Mc]

Even the race tracks around here are saying they will not be able to get non-ethanol gas in the near future (some say September 2010, some say December).

As far as Aviation fuel goes, "low lead" is a misnomer. It's called 100LL with the LL standing for low lead. It's only "low" compared to the amount of lead in 100 octane avgas from about 20 years ago. 100LL still has about 3 times as much lead as the old leaded auto fuel.

John Mc

[LorenB]

As far as Aviation fuel goes, "low lead" is a misnomer. It's called 100LL with the LL standing for low lead. It's only "low" compared to the amount of lead in 100 octane avgas from about 20 years ago. 100LL still has about 3 times as much lead as the old leaded auto fuel.

John Mc

That's correct about the "low lead" AvGas, but just because it has lead doesn't mean it's bad for your saw.  My saw is far from new, but I'd guess that even the new ones still don't have a catalytic converter.  Those converters in autos and trucks were the original reason for lead-free gasoline.  Lead will ruin a converter. 

I'm not a professional so my saws don't see as much use in a year as some saws see in a week, but I've been running 100LL AvGas for several years with no trouble. 

AvGas does not deteriorate with time and so needs no fuel stabilizer. 

– Loren

[John Mc]

Lots of saws do have catalytic mufflers these days (my Jonsered 2152 did, but I swapped it out for a non-cat muffler). Chainsaw probably run hot enough to scavenge the lead and avoid lead fouling -- if you don't let them idle much. Fouling the oil isn't an issue as it is in four cycle engines, since with a 2-stroke you are essentially changing the oil every time you refuel.

However, it wasn't the saw I was primarily worried about, it was me (or bringing the residue home on my clothes to my kids). I worked for a number of years in a factory that heat treated steel wire by running it through baths of molten lead. I've had a healthy respect for the problems with lead drilled in to me. We had to go through regular mandatory training on the effects of lead on humans, and people who worked around it regularly had to get blood tests to make sure they weren't getting over-exposed. It was mandatory for people who worked in that department to shower before leaving the facility, and we provided uniforms which they left at work and we had sent out to clean, so they wouldn't drag any lead residue home where it might affect "junior". Tetraethyl lead is a particularly troublesome form. It's more easily absorbed into the body than some other forms. When my wife was pregnant (or even when we were "trying") we made sure she never refueled the plane... just not worth the risk.

John Mc

[pallis]

Gas and ethanol will separate if you add water, shake very well, and let it sit for a while. You could then drain off the ethanol/water mix from the bottom. Best to do this before you add stabilizer or mix oil. There may still be a bot of ethanol or water in the gas, but it will be slight (the colder the gas, the less water it will hold)

Note that E10 gas (gas with ethanol) gets about 4 of it's octane rating from the ethanol. If you start with premium E10 (93 Octane) you'll ed up with about 89 Octane... probably still OK for most stock chainsaws. If you start with 87 (regular) or 89 (mid-grade), you've got a problem when you take the ethanol out. You'll end up with about 83 or 85 octane - not good for a chainsaw (or a lot of other engines)

You can add octane boosters, but there are two things to consider with this. The labeling on some octane boosters is a bit misleading. When some of the labels say "adds two points of octane" what they mean is 0.2, not 2.0. Also, some octane boosters are mainly alcohol of one form or another, so you are just adding the problem back in when you add them.

John Mc

Thanks!  I wasn't sure about the octane boosters, but I thought they might be alcohol.   I think I'll try your idea of starting with premium and washing it with water.  My problem is that the temperature at my house has been in the high eighties to high nineties.  That's around 6000 ft.  Where I've been cutting is over 10,000 with temps going from the 60s to the 90s.  I'm using premium gas with a 32/1 synthetic mix and stabil, and by the second or third day of back and forth my saws don't like the gas.   The simple solution is to get enough fuel to last for one trip, and use it all.  That would be too easy. 

A station here used to sell high octane fuel for the car shows, but that's a thing of the past.  I haven't tried our little airport yet.  None of my saws have catalytic converters, so a little lead shouldn't be a problem.

Thanks to everyone!

[Okrafarmer]

When I worked at the airport in 2005, we had to run tests (every so often) on the av gas and jet fuel. When the fuel was removed from the tanks for testing  it could not be reused in aircraft. The av gas(100LL) was dumped into the tank of the current model car run by the FBO and the jet fuel we used in the diesel tug. They had been doing that for years. . . . .

[John Mc]

The av gas(100LL) was dumped into the tank of the current model car run by the FBO ... They had been doing that for years. . . . .

That 100LL WILL eventually kill your catalytic converter, even in small concentrations. It screws up the catalyst. The effect is cumulative, so even diluted, it will eventually be a problem.

[John Mc]

... I think I'll try your idea of starting with premium and washing it with water.  My problem is that the temperature at my house has been in the high eighties to high nineties.  That's around 6000 ft.  Where I've been cutting is over 10,000 with temps going from the 60s to the 90s.  I'm using premium gas with a 32/1 synthetic mix and stabil, and by the second or third day of back and forth my saws don't like the gas.   The simple solution is to get enough fuel to last for one trip, and use it all.  That would be too easy.

Two or three days seems excessively short for shelf life, even on ethanol blend gas. I wonder if you have something else going on?

Are you using the Marine formula Stabil (the blue stuff)? The red Stabil is not so good with ethanol.

Is the gas you are using already "stale" even before you mix it?

Is your saw tuned to run at 6000 ft elevation, or 10,000 feet? I've never run a saw at those altitudes, but I would think it can make a difference (unless you've got one of those newer "Auto-tune" saws??) I know in a piston engine aircraft, you have to adjust the mixture significantly as you climb.

I wonder if the wide temperature swings have anything to do with it? Gas will hold some water in suspension (even gas with no ethanol). How much is dependent on temperature. The hotter it is, the more water the gas can hold. Usually, this will just run right through the engine, since it's so diluted. If your gas is holding all it can at 90 degrees, some may drop out when you get up into a 60 degree area... then you've got a little puddle of water in the bottom of your gas can or fuel tank. (This also might mean if you are trying to wash the ethanol out, the colder your fuel the better, so more of the water you add will drop out. If I were going to try this, I'd might try it when fresh out of the pump - the underground tank should keep it significantly cooler than your 90 degree days.)

Another thought on temperature swings: this will cause your gas can and saw's fuel tank to "breathe" as the air and fuel in the tanks expands and contracts with temperature. That breathing pulls in a new slug of air, which contains some moisture, allowing the ethanol a chance to combine with even more water. This might be a long shot, but I'd be curious if the gas would last longer if you left it up at the cooler elevations, rather than bringing it home each day.

Just curious... why are you running 32:1 on your mix? 50:1 should work fine if you are using a good quality mix oil (I usually shoot for 45:1 to allow for measurement errors). If you are dead set on running that ratio, is your carb adjusted to running that mix?

Just some rambling thoughts. If you try any of this stuff, I'd be curious to hear if it made a difference.

[pallis]

"Two or three days seems excessively short for shelf life, even on ethanol blend gas. I wonder if you have something else going on?"

I agree, and I've never had this problem before, so I don't have much speculation on what is causing it, other than it has been more humid here than normal, and there is more ethanol in the fuel.  I always use premium right out of the pump for my mix, so unless the gas is bad coming out of the pump, it should be fresh.

"Is your saw tuned to run at 6000 ft elevation, or 10,000 feet? I've never run a saw at those altitudes, but I would think it can make a difference (unless you've got one of those newer "Auto-tune" saws??) I know in a piston engine aircraft, you have to adjust the mixture significantly as you climb."

Once over 10,000 I have to lean the saws out a bit, cutting under that, say 8,000, I've never had a problem.  The saws I use are a 7900, a 372 and a 5100, all with modded mufflers and fully adjustable carbs.  The 5100 has been modded, and oddly enough, it was effected the least.  (And, a little Oleo-Mac 951 and newer Efco 152 deserve mention.  They only get used if there are several of us cutting, but this is the first time the 951 failed to start and run like a champ).  ...I've got an auto tune carb on a little Terramite loader, and I don't want that kind of a problem on my saws.

"Just curious... why are you running 32:1 on your mix?"

I've never blown a saw.  Whether or not 32:1 is the best, if 40:1 or 50:1 would work as well, I don't know, and so far I haven't had a reason to find out.  In reading all the opinions, debates and outright fights over what is the best oil mix and why, I don't have much of an opinion, other than that my saws have always run great, and I'm always hearing about the saw that crapped out on 50:1.  This problem will have to be solved at 32:1 ;D ...I used the Mobile synthetics until I couldn't get them.  I've used the  synthetic Bailey's sells for the past few years.  I don't think there is a problem with the oil or the ratio, but you could be right about the red Stabil.   I've got some marine Stabil for the boat, so I'll try that.

I've been buried with other problems, out of work kids, complete with grandkids and dogs moving back in, the outdrive and gimbal on the boat, the tractor, some welding jobs and so on, but I should be back into the woods soon.  Of course the temperature is getting cooler, so the problem might fix itself, or maybe it was some kind of fluke to start with.

Thanks much for all the advise and knowledge.

[John Mc]

The red Stabil may have alcohol as one of its ingredients. If so, that can make ethanol problems worse... it's like adding a bit more ethanol to the mix.