Petrol = gasoline = fuel storage questions.

My next test will be with the cap on tight,
This will avoid the evaporation issue.

I will also have a 3rd test going with the fuel mixed with stabilizer, I have managed to get a small bottle of Briggs and Stratton Stabilizer.

 

You know Manie, a hole not much bigger than a pin hole will provide adequate venting without any measureable evaporation.

You really don't want any pressure build up, positive or negative...

 

Tom a pin hole will already ventilate the light gasses, they need very little pressure to evaporate and escape. The second bottle test must be closed. The pressure is never that great that the bottle would burst. I will test the closed bottle in the hot sun as well.
My fuel tanks - which are standard Yamaha - cant hold pressure anyway.
With the vent closed and in the sun - the tank swells up, there is good pressure in the tank, but the cap releases the peak pressure, the cap is not designed to hold big pressure.

 

I agree - variations in temperature cause a tank to pump air in and out.

 

Opps...

I think you need to repeat the experiment with a different grade of plastic. One that has a high gasoline permeation resistance.

I believe PET plastic bottles are gas permeation sieves.

Test with the same plastics that are used for fuel tanks and fuel hose.

" Permeation is the process by which smaller hydro
carbon molecules pass through the chemical chain of the cross-linked polyethylene. That permeation can be described as a “wicking effect”. Fuel
odor is the end result of this process; note this is a normal occurrence in plastic fuel tanks and should not be confused with fuel vapor.
Permeation Key Drivers:
1. Storage temperatures increase the permeation rate: for every 50 F / 10 C (degree(s)), the rate doubles.
2. Pressurized fuel tanks will increase the permeation rate.
3. Ethanol Blends will increase permeation rates.

"

 

thanks Michael - interesting

 

This is what the American EPA ...new gas tank guidelines..is all about.

Gasoline permeation.

I don't understand it but I see the phrase over and over again on marine fuel system components.

It looks like alchol in fuel contributes to the problem

 

Best way to get round this silly problem is live somewhere that doesnt have people sitting wasting time making more and more slilly laws to stop idiocy.

Blowing yourself up with a petrol tank needs incredible stupidity and or understanding of petrol . This has nothing at all to do with the tank but the brain of the owner of it and there lies the sole problem of the matter.

Evolution if left to its own devices is meant to weed out idiots and if left alone works well.

 

I think the new rules are a great idea, might help the alcohol issues to go away or at least diminish
Hoses should have been like this since they invented fuel hose

 

EPA just approved 15% ethanol. Farmers' lobby bought political favors.

 

I use E 20. Ille drive to get to it, fantastic stuff. I use it on all vehicles I have that uses petrol then douse it with 10% deisel ...

I think I said this once

 

talk about global warming , and I think this month was the greatest ever US import of ethanol?

 

How much heat is generated to manufacture ethanol? Heat is definitely needed for the distillation process. How much energy is expended for the amount of energy stored in the ethanol?

How much gasoline is ruined because it had ethanol in it?

How many engines have been ruined because they tried to run on ethanolized fuel?

How much energy was wasted manufacturing those engines and delivering them or their components just so they could be ruined by ethanol?

http://www.sciencedaily.com/releases/2005/03/050329132436.htm

"It may sound green, Patzek says, but that's because many scientists are not looking at the whole picture. According to his research, more fossil energy is used to produce ethanol than the energy contained within it."

 

We burn more fossil fuel making ethanol than we acquire in ethanol. Did you not read the quote from Science Daily which you mysteriously omitted from my previous post? Here it is again.

"It may sound green, Patzek says, but that's because many scientists are not looking at the whole picture. According to his research, more fossil energy is used to produce ethanol than the energy contained within it."