Gas stabilizer, Whats good and whats not as good??

[wingtime]

The condensation problem is VERY real.  While it may not happen that often it does happen.  In aviation we have to sump our tanks before we fly and tanks that have sat for some time with less than full tanks will have water in them.   Now Avgas is a whole different animal than the crappy ethanol mogas we use in the boats today.  The alcohol in ethanol fuel will actually adsorb water until it reaches the saturation point then it will phase separate.  I'm not even sure if small  amounts of water will even form a bubble in ethanol fuel since it soluble with the alcohol.     Now one could argue that certain types of tanks and installations will be more susceptible to condensation than others.  

I would think a metal tank would be the worst case.  I also believe it happens in reverse of what you think...  I think a tank full of warm humid air is suddenly exposed to cooler outside air will get condensation on the inside of the tank since the aluminum walls of the tank will cool much fast than the air inside.  All it takes is a day with a close temperature dew point spread.  At least that is my theory on the subject.

[fitz73222]

I would think that aircraft would be susceptible to water and condensation because of the exposed wing tanks being constantly heated and cooled just in a normal flight? I don`t seem to have water issues whether the boats are stored indoors or under a cover outside. Full or empty. I always put in the Sartron per instructions.  I cant ever remember draining any water out of the sightbowls on any of them and I am anal about it. I just see the normal particulate matter. I run Hess gas from a high volume dealer so the fuel is always fresh. Unless its winter time and dont plan on running the boat for a month or two. I leave the gas lines plugged in the motors year round and dont run them out of gas and dont have carburator issues. So I dont know if this is a regional issue or what? I here a lot of talk about poor fuel quality in the Virginia`s is it true?

[GoneFission]

Be careful with what goes in the tank as well.  One of these is not a bad investment for less than $25:

http://cgi.ebay.com/ebaymotors/Racor-RF ... ccessories  

See ya on the water!

[John Jones]

Yup.  You can get the same funnel at West Marine for around $25.  Every drop of gas that goes into my boat goes through one of them.  They make a large size that will handle a gas station full flow.

http://www.mrfunnel.com/Mr._Funnel/Home.html

[RebelYell]

..

Good Morning Everyone-

I would like to "add my two cents" to the discussion about E10 fuels and phase separation.

I work as a Chemist and have worked for 23 years in fuels, pharmaceuticals, and now in phytochemical ( natural products ) research.

Phase seperation is REAL. I don't care what Pascoe says. I trust his advice on many things but he is wrong about this one. Of course he's not formally educated as a Chemist either.

Ethanol is an extremely hygroscopic compound that will readily absorb uncondensed moisture in the atmosphere. Condensation ( vapor turning to water ) is NOT a requirement for Ethanol to be able to absorb water. All you need is headspace in the tank that is filled with humid air and Ethanol will suck it right out at the air/liquid interface.

In fact, completely dry, 100% Ethanol is very, very expensive to obtain and must be stored in very dry conditions; typically under a headspace of dry, inert gas ( Nitrogen or Helium would work ).

Ethanol forms an "azoetrope" ( google it ) with water and requires several successive distillations to remove most of the water....but with distillation alone you cannot remove it all. Typically they further dry the ethanol with calcium carbonate or run it through a molecular sieve to achieve a 99.999% dry product.

What happens in our case, and in plainer words, is that you fill the tank with E10 and everything is cool at first. If you have a headspace in the tank and an open vent to the outside ( as boats do ) humid air will enter the tank and become miscible (dissolve) with the ethanol / fuel mixture at the interface. If ethanol were not present this would barely happen at all.

For awhile, the ethanol will absorb the water and remain miscible with the gasoline. However, at a certain point of water saturation, the ethanol/water/fuel mixture can no longer remain homogenous ( and dissolved ) and a more polar layer of ethanol / water forms that is no longer miscible with the fuel.

This layer is a bad thing, man. At the interface of the methanol/water and gasoline layers ( where the two layers meet ) the solution becomes extremely caustic and will corrode just about any metal. Steel and aluminum don't stand a chance. Pump some of this stuff up into your carbs with 2 stroke oil mixed in and you have a mixture that will corrode your metals, eat through your plastics and rubber seals, and leave a gooey varnish deposited all over certain surfaces.

Pascoe makes a nice sounding arguement, but he's dead wrong.

What most of these additives do is adsorb (sequester) the ethanol that is mixed with your fuel; making it unavailable to absorb water from the atmosphere to form a phase separation. Essentially they add light-end very highly refined short chain hydrocarbons that are more polar than regular gas hydrocarbons and they "soak up" the ethanol and don't allow it to absorb water. Some of these treatments also include certain enzymes that help to break down ( or digest )any oil/water/fuel sludges that have formed as a result of phase separation.

Sorry for the large post, but there's a lot of misinformation out there.

SeaFoam, Startron, and several other brands out there do essentially the same thing with slightly different formulas.

I use SeaFoam and Startron in my boat.


 :joker:

[gran398]

reb, great post. Thanks for taking the time...and great to have a chemist onboard!

[fitz73222]

Thank you for very informative post. Based on the discussion can I draw the following conclusions?
Does water from whatever source be it humidty, physical intrusion, etc stay in suspension until it forms the stratified layer or does it migrate to the bottom of the tank due to specific gravity and then move from the bottom of the tank into the stratified layer over time? My point in asking is that you could have water in your fuel in normal suspension that would not show up in your sight bowl? Addtionally, once the phase separation has occured, water laiden gasoline falls to the bottom of tank and the usable fuel is above it? It has been said and advertized that a 10 Micron filter media is small enough to catch the water laiden fuel due to its 30 micron size once combined. Essentially it will plug the filter but keep the contaminated fuel from reaching the engine.

[pete]

Woww great post!Thanks for the info I have been using the startron and yammy ring free with good results.

[flounderpounder225]

WOW !! Thanks for the better explanation, got one thing at the end of it... Startron!!!  Yeah, if the Chemist is using it... that's what I've been using..