Tackling Ethanol

[grady]

Hi everyone, I'm starting to consider what componets to install in my new fuel delivery system. I hear that Ethanol eats at rubber and other parts of a fuel system, Just wanted to treat the headache before it got costly.

Here's the back ground info:

Two new alum tanks
single volvo penta mpi sm blk
duoprop

since everything is new I'm hoping the motor has penatration resistance plumbing on it, so it's just the fuel fill hoses and the feed hoses to the motor.

Is there a special type of hose that resist breaking down?
Do I need to worry about it?
What's the best type of hose to use?

Also I've heard that instead of leaving your tanks topped off for the winter, you should leave as little as possible to limit the amount of moisture that the ethanol can absorb. True or false?

Please any info is useful, any thanks for your time and consieration.

[the1much]

i dont know much about ethenol,,,,but dont leave ya tanks empty,,,the more "air space" you have,,the more moisture you get,,,,,when i first started winterizing boats,,,i was told by people to always leave ya tank empty,,,,then all the problems in the spring made me ask the "old timers",,they said,,,,,use ya dam head,,,,if ya fill something to the top,,,how can moisture get in there?
see,,i cant even type about something even that simple,,,,hehe

[the1much]

notha idea,,,,,,we use stainless steel tubing on our separators because other hoses get eatin out so fast.

[grady]

The old school of thought was that the variation in temps would promote condensation, and that would appear in the tank as moisture, but now the ethanol chemically attracts moisture out of the atmosphere and the more ethanol the more moisture it will attract.

[the1much]

it cant attract it if theres no room for it ( heres my coke can theory again haha)
fill a bottle of gas half full,,,,put top on,,,do another bottle filled to the very top, put top on,,,set em outside,,,,tomorrow the 1 half full will have moisture on the bottle sides and top where there is no gas,,,,,,now the other one,,,,,wheres the moisture?,,,,,,,,,,,,,,,,,,,and on the empty tank theory,,,will you ever be able to get all the ethanol out of it?,,,and there will be fumes in it for years,,,and will attract all kinds of moisture over night.,,,,,,( jus so ya know,,,,i actually did the "bottle" thingy to see who knew what,,hehe )

[Ike]

Type A and B USCG fuel hose is alcohol resistant. In fact it has been since the mid 80's. So you need to be concerned mainly with phase separation of the fuel in the tank while the boat is in storage. The best solution is store it with tanks empty. But if you must store it with fuel in the tank, fill the tank and add a stabilizer and a co-inhibiter.

Here's a link to read http://newboatbuilders.com/docs/Ethanol.pdf

Next year there will be a new type of hose on the market that is not only alcohol resistant and meets all the USCG requirements, but will also meet the EPA requirements for evaporative emmissions.

[longliner45]

is ethanal similar to alcohal ,,drives off moister?

[the1much]

doesnt it take certain things to create moisture?,,,wouldnt oxygen be 1 of those things?,,and it isnt like its "drawing in" water from the outside,,it all has to happen "inside" the tank,,,,so wouldnt another thing needed is "evaporation",,which needs "space" to rise to cause moisture?,,,,
dammit Grady!!!
this is another one of those "chicken or the egg" questions!!!,,,causes more questions then answers,,,,,,,makes my brain "fart",,hehe
would 1 of you smaht people answer this!!
hehe

[Ike]

geez. If you read the link I gave you would know the answer to your questions.

Ethanol is alcohol. Ethyl alcohol. The word ethanol was probably invented by the oil companies to keep you from knowing you could just pour a bottle of vodka in the tank and get the same result. This is as opposed to methanol which you shouldn't drink. Methyl alcohol which is used in racing engines and rocketships, and medicine to sterilize stuff. Methanol will kill you a lot quicker than Ethanol which can kill you too if you have too much whiskey.

Etthyl alcohol is "hydrophilic", a good $25 word than means water loving. I love the water too, but I'm not hydrophilic. Anyway, that means that it attracts any nearby water. So for years people have used it to de-ice their windshields and fuel lines and get water out of the gas. Which brings us to our point.

If you put alcohol in your gasoline, the two don't mix well. They don't like each other much so they eventually separate... Kind of like some marriages. OH Oh Getting off track again.

This is called phase separation and you can actually perform this trick yourself. Just pour some gas that has alcohol in it into a glass beaker, let it sit overnight, and in the morning, presto chango, you will have two layers. (don't do this inside your house) One thin one on the bottom, alcohol, and a thick one on the top, gas. If you want to speed up the process, pour in a little water, give it a good shake and it will rather quickly sepate in three layers. Not in a couple of minutes but more like in a few hours, sort of about the rate that grass grows. As we have all been told since we were nusiances to our parents, water and alcohol don't mix. But they do attract, so you get a layer of alcohol, a layer of water and a layer of gas.

NOW, the bad stuff happens. At the interface between these layers, (Interface is a $30 word for line), you get other compounds that form, mostly acids. Acids like to eat things, especially metal tanks. Plastic tanks are immune for some reason. They don't get eaten.

Now how about hose?? Hose used to be rubber. Alcohol loves rubber. It migrates right through and while it does it attacks the things called parafins that make rubber, uhhhhh, rubbery. Alcohol as we all know is a great solvent. It will dissolve all kinds of things, thats why it's used in a lot of cleaners. It also disssolves things we don't want it to, like plasticizers, the parafins I spoke of, litterally, wax. This makes the hose go all soft an gushy at first then it gets hard and cracks. Back in the 80's when gasohol was the rage The Coast Guard, ABYC, SAE and a bunch of other alphabet soup organizations decided something had to be done, so they changed the compounds in marine fuel hose so that the alcohol wouldn't do that anymore. Plus that they added a plastic sleeve inside the hose to keep alcohol and gas from migrating (permeating, another big word) out through the walls of the hose.

SO what do you do? One, you can empty the tank. Not an option? Fill it all the way (less air for mositure to condense out of) and a stabilizer (keeps the alcohol and gas from separating) and a co-inhibitor (keeps the acid compounds from forming.)

And yes there have been some studies that show that not much moisture condenses out of the air inside a tank. But they didn't take into account extreme temperature cycles and freeze thaw cycles. So the jury is still out.

[grady]

Well, thanks guys, I just want to make sure that my hoses wouldn't turn to mush.

Ike, thanks for the link and that great reply.

Much, thanks for your bottle experiment, as far as the chicken and the egg goes, I thought you had answered that in that great joke you had in the joke thread.

[the1much]

im sure it was the omelet first hehe

[FAST FRED]

Also I've heard that instead of leaving your tanks topped off for the winter, you should leave as little as possible to limit the amount of moisture that the ethanol can absorb. True or false?

SO true , but the best defense is to REMOVE all the fuel and leave the tank empty.
A simple setup will allow you to defuel to your car via gas cans , at the end of the season.

"A stitch in time can save 9"

FF

[the1much]

is there a way to completely empty your fuel tank?,,cause just a tablespoon of fuel will cause twice as much moisture.

[FAST FRED]

Most automotive fuel pumps will do 60GPH with ease ,so filling a 5gal can to defule wont take that long.

What ever is left after emptying probably is not enough to worry about on spring fillup.

Gas engines can eat mucho rotten fuel and crud (unlike diesels) or the current federally mandated garbage fuel would have stopped every car in the USA, long ago.

For folks with outboards , remember the fuel dies more rapidly as the oil is mixed in , so only mix what you will burn for each outing, NO MORE.

Never store mixed OB fuel , dump it in your trusty car , think of the extra oil as top cylinder lube.

FF

[rwatson]

I am not sure that water and alchohol separate.

I was always tol that if you have water in your tank, that you add say. methylated spirits to the tank, the water will be absorbed by the alchohol and you wiont have engine problems

As per
water in gas tank


I also quickly looked up this quote

"isopropyl alcohol is soluble in water. In fact, better than that, it is fully miscible in water. This means the two liquids will mix in all proportions, forming a homogeneous solution. "