Gas Cans/Ethanol

[bwalker]

Looks like it was dropped or stabbed with a screwdriver to me.

UV tears up plastics, particularly polyethylene, by breaking bonds in the long polymer molecules. It doesn't need to "bleach the plastic white" -- the damage can be virtually invisible.

As a fisherman and general junk collector, I have many uses for those 5-gallon PE paint and mud buckets and will usually stop if I see one by the side of the road, to pick it up. Quickest way to assess the UV damage on those PE buckets is to squeeze them across the top. If they crack, they're shot through with UV. I've been surprised on many occasions when I thought I'd found a fairly new bucket and squeezed it and -- CRACK. I guess there's a bit of variation in how much UV blocker manufacturers put into the resin.

Well, it wasn't stabbed or dropped...
And it spent the majority of its life sitting in my shop. It was never left outdoors.
I do have one can I bought used and it's sun bleached.

 

[Hermio]

I wouldn't actually fly on 10 year old fuel either, even if it burns.

My experience with ethanol issues is that it turns plastic and rubber into goo, not hardens them. Plenty of OEM fuel tanks in vehicles are HDPE also, I doubt it was the ethanol that killed your gas can.

Ethanol does not harm HDPE

 

[wildwes]

Looks like it was dropped or stabbed with a screwdriver to me. (I've also heard that squirrels like to chew on gas cans, especially ones containing gasohol.)

UV tears up plastics, particularly polyethylene, by breaking bonds in the long polymer-chain molecules. It doesn't need to "bleach the plastic white" -- the damage can be virtually invisible.

As a fisherman and general junk collector, I have many uses for those 5-gallon PE paint and mud buckets and will usually stop if I see one by the side of the road, to pick it up. Quickest way to assess the UV damage on those PE buckets is to squeeze them across the top (mouth) of the bucket. If they crack, they're shot through with UV. I've been surprised on many occasions when I thought I'd found a fairly new bucket and squeezed it and -- CRACK. I guess there's a bit of variation in how much UV blocker manufacturers put into the resin.

Maybe it was just a bad spot in the plastic?
RE squirrels and gas cans- I have had a couple of small 1 gallon blitz cans get chewed through by squirrels.

I use hydraulic oil and motor oil 5 gallon buckets as fuel cans for diesel, but I don't store it in them for more than a few weeks at a time.

 

[Smitty Smithsonite]

3 things kill plastic - heat, UV, and OZONE. If you store it in a shop, barn, or garage with electric motors stopping / starting throughout the day, I'd wager it's due to the ozone formed.

I've got around 12 or so plastic cans that have had E10, diesel, and E0 in them for DECADES without issue. Some of my cans are 30+ years old!

 

[scottr]

3 things kill plastic - heat, UV, and OZONE. If you store it in a shop, barn, or garage with electric motors stopping / starting throughout the day, I'd wager it's due to the ozone formed.

I've got around 12 or so plastic cans that have had E10, diesel, and E0 in them for DECADES without issue. Some of my cans are 30+ years old!

I have a few very old red plastic gas jugs that are good .
Are your 12 or so plastic cans red gasoline cans ?

 

[SS396driver]

3 things kill plastic - heat, UV, and OZONE. If you store it in a shop, barn, or garage with electric motors stopping / starting throughout the day, I'd wager it's due to the ozone formed.

I've got around 12 or so plastic cans that have had E10, diesel, and E0 in them for DECADES without issue. Some of my cans are 30+ years old!

That’s why my compressor isn’t in the garage where I store my old cars . Kills the rubber

 

[Smitty Smithsonite]

I have a few very old red plastic gas jugs that are good .
Are your 12 or so plastic cans red gasoline cans ?

Most are. I have a couple blue and yellow kerosene & diesel cans that'll sometimes get filled with gasoline if I run out of cans in the course of rotation (oldest gets used first).

 

[smcowboy1974]

The stupid part was referring to burning leaded fuel in a hand held piece of equipment.

Oh, but it smells so good, especially in old tractors. And the exhaust pipe gets that nice light gray color inside of it.

 

[bwalker]

Ethanol does not harm HDPE

Would you take a guess what would cause a can to get brittle like this? Given your background you might know.

 

[bwalker]

3 things kill plastic - heat, UV, and OZONE. If you store it in a shop, barn, or garage with electric motors stopping / starting throughout the day, I'd wager it's due to the ozone formed.

I've got around 12 or so plastic cans that have had E10, diesel, and E0 in them for DECADES without issue. Some of my cans are 30+ years old!

That's interesting. I do have two chest freezers in my shop. I wonder if ozone is what did the can in?

 

[Smitty Smithsonite]

Usually compressors are hermetically sealed in refrigeration equipment.

 

[OM617YOTA]

Wouldn't surprise me if someone just plain screwed up the blending on the plastic for that particular batch of cans. Got through their warranty period = not their problem anymore.

 

[Mad Professor]

It's not the ethanol. Excellent resistance.

Look at/compare some of the other hydrocarbon components found in gasoline.

 

[Hermio]

Would you take a guess what would cause a can to get brittle like this? Given your background you might know.

I don't know what the plastic composition is, but many plastics have plasticizers to make them less brittle. Over time, the plasticizers can evaporate (this is what happens to vinyl car seats over a period of years, especially if left outdoors where the sun can cause interior temperatures to exceed 150F). They plasticizers can also leach out due to solvent action. I do not know if gasoline or ethanol can do this; it depends on the plasticizer. It would seem strange, though, for a manufacturer to use a plasticizer in a fuel can that is soluble in petroleum products. And of course, UV destroys plastic, but you said the can was stored indoors, so that can be ruled out. I am not sure this is possible, but maybe the polymerization process continues very slowly over the years, which would lead to a higher molecular weight and higher rigidity/brittleness. For my own part, I have some fuel cans made of plastic that are over 20 years old, and none have failed. So, I don't have a certain explanation. I have designed a few polymer reactors, but I have not been involved in the actual chemistry or compounding of plastics. I just deal with the fluid dynamics. I do know that pure HDPE is immune to both petroleum products and ethanol.

 

[Mad Professor]

I don't know what the plastic composition is, but many plastics have plasticizers to make them less brittle. Over time, the plasticizers can evaporate (this is what happens to vinyl car seats over a period of years, especially if left outdoors where the sun can cause interior temperatures to exceed 150F). They plasticizers can also leach out due to solvent action. I do not know if gasoline or ethanol can do this; it depends on the plasticizer. It would seem strange, though, for a manufacturer to use a plasticizer in a fuel can that is soluble in petroleum products. And of course, UV destroys plastic, but you said the can was stored indoors, so that can be ruled out. I am not sure this is possible, but maybe the polymerization process continues very slowly over the years, which would lead to a higher molecular weight and higher rigidity/brittleness. For my own part, I have some fuel cans made of plastic that are over 20 years old, and none have failed. So, I don't have a certain explanation. I have designed a few polymer reactors, but I have not been involved in the actual chemistry or compounding of plastics. I just deal with the fluid dynamics. I do know that pure HDPE is immune to both petroleum products and ethanol.

Not really. It does not handle aromatics well. Some are hydrocarbons are temperature dependent.

I did a lot of organic chemistry research, and also set up chemistry laboratories.

 

[Hermio]

Not really. It does not handle aromatics well. Some are hydrocarbons are temperature dependent.

I did a lot of organic chemistry research, and also set up chemistry laboratories.

I should have been more specific. I was referring to the petroleum products used as fuel, which are mostly straight chain hydrocarbons, i.e., alkanes. I was unaware until now that aromatics are added to gasoline to boost octane. Since ethanol is also an octane booster, they would need less of an aromatic content for a given octane rating. Ironically, that may mean that gasahol is less harmful to plastic fuel cans than straight gasoline, and that higher octane blends may be more harmful.

 

[NSEric]

Plastic gas cans made within the last 20 or so years are cheap and junk for the most part.
They just dont last a long time no matter what you do with them.

 

[bwalker]

8

I should have been more specific. I was referring to the petroleum products used as fuel, which are mostly straight chain hydrocarbons, i.e., alkanes. I was unaware until now that aromatics are added to gasoline to boost octane. Since ethanol is also an octane booster, they would need less of an aromatic content for a given octane rating. Ironically, that may mean that gasahol is less harmful to plastic fuel cans than straight gasoline, and that higher octane blends may be more harmful.

Aromatic levels in modern gasoline is extremely low. The EPA has a limit on Benzene, which forced refiners to add BRU or Benzen Reduction Units. These units reduce all ring structured molecules.
Even back before the EPA Benzene regulation many refiners seperated out their aromatics and sold them as they are substantially more valuable than gasoline.

 

[Mad Professor]

I should have been more specific. I was referring to the petroleum products used as fuel, which are mostly straight chain hydrocarbons, i.e., alkanes. I was unaware until now that aromatics are added to gasoline to boost octane. Since ethanol is also an octane booster, they would need less of an aromatic content for a given octane rating. Ironically, that may mean that gasahol is less harmful to plastic fuel cans than straight gasoline, and that higher octane blends may be more harmful.

We ran a teaching lab in Analytic Chemistry class where students analyzed all sorts of fuel samples:gasolines, diesel, fuel oil, AV gas.

The analyses were by GC/MS and all the components were separated, then identified and quantified. This was years ago for me and I no longer have any of their reports to give you actual numbers.

It was a good exercise in learning both gas chromotography (separation) and mass spectrometry (identification and quantification).

There has been an effort to reduce benzene content due to carcinogenicity, but toluene and xylenes are common and small amounts of metisylenes.

It was also interesting to see how much trace amounts of heterocyclic compounds were in diesel and fuel oils. "Low sulfur" being the goal.

 

[Mad Professor]

Plastic gas cans made within the last 20 or so years are cheap and junk for the most part.
They just dont last a long time no matter what you do with them.

I am more irritated by the designs with asinine spouts and vents.

The plastic technology/formulations has probably improved