Plastic UV deterioration

[Marin]

A question for anyone who knows something about the UV degredation of plastic.* We have four plastic 5-gallon gas cans, the kind you can buy at any auto parts store, Home Despot, etc.

I noticed the other day that two of them have gotten quite pink in the upper third of the can.* Due, I assume, to them having sat outside for quite a long time this year.* I'm thinking that this is the result of UV exposure, but what I don't know is if the plastic these cans are typically made of is subject to deterioration and "brittilization" (a new word I think) from long exposure to UV light.* The other two cans look the same as when we bought them.

These things are pretty cheap so my inclination is to throw the two faded ones out and replace them rather than risk the seam coming apart or something when they're full of fuel.* I've had a plastic footstool disintegrate under me after a few years of sitting outside on the aft deck of the boat.

Anyone know if this kind of gas can will deteriorate when exposed to UV for a long time?

Thanks,

 

[Doc]

Down here in SW Florida we have hot days and cool nights. My red tank, Temko I think, finally got tired expanding like a bloated whale in the day time and going to prune mode at night. It split at a seam...but it took five years to this.

Pink has got to be stetched red. I would get some new ones.

 

[markpierce]

I'm curiuous as to why you have multiple plastic containers exposed to the elements.

 

[C lectric]

Yes, the plastic, a type of polyethylene will degrade.
Gasoline is terrible for pressurizing a container. The vapour pressure is far greater than diesel when exposed to the sun. I have had two 5 gal gas jugs split at the seam.

\I try to cover them with a towel. I have thought??? sometimes of making a cover to protect them. They live on the swimgrid. Per the ?? about why are they exposed- no other place to put them. I won't put them inside the hull anywhere. Of course covers would fix the problem

Replace them every few years although they can be long lived if given minimal cover.

 

[markpierce]

Attaching gasoline "bombs" around my home/boat?***

**Not I!

 

[koliver]

A friend of mine tried to get me to replace my pink fuel tank in my dinghy for several years. I eventually sold the dingy, pink tank and all, so I don't know how much longer it lasted. I also have a tank that was leaking, that I cut the side out of to use for catching engine in changing the oil in my car. It is also pink, and doesnt seem to be weak as a result. The leak was at a seam.

 

[Carey]

C lectric wrote:

Yes, the plastic, a type of polyethylene will degrade.
Gasoline is terrible for pressurizing a container. The vapour pressure is far greater than diesel when exposed to the sun. I have had two 5 gal gas jugs split at the seam.

\I try to cover them with a towel. I have thought??? sometimes of making a cover to protect them. They live on the swimgrid. Per the ?? about why are they exposed- no other place to put them. I won't put them inside the hull anywhere. Of course covers would fix the problem

Replace them every few years although they can be long lived if given minimal cover.

MarinAs you know, I had an 11 gallon aluminum tank custom built to be a combination tank and seat in my dinghy many years ago. No regrets. Probably cost no more than 2x the cost of your pink tanks. Think about that for your swim grid. We have several folks here in Bellingham who can build one for you.


-- Edited by Carey on Sunday 21st of November 2010 08:27:07 PM

 

[C lectric]

What do you have for a dinghy, diesel? We carry gasoline for the outboard. At least for us and most of the the rest of us there is no practical other choice , sans rowing/sailing dingbats.

So at least on the swimgrid it's outside the hull.

 

[Marin]

Given the questions I guess I should explain---- The four 5 gallon gas cans I referred to are for fuel for our generator at home and also for extra fuel when we take our outboard fishing boat up the north end of Vancouver Island for halibut fishing in the spring. Fuel's expensive up there so we try to take as much as we can with us. However the BC ferries limit the number of gas cans you can take to three-- two for a boat and one for a vehicle. We had a fourth can with us last year and we had to fill it with water before they would allow it on the ferry.* The two cans that have turned pink have been sitting on the back deck of our house (empty) for about five months.

For the outboard on our dinghy on the GB we carry a small two gallon can for filling the built-in tank on the Yamaha and one of those flat five gallon cans, both plastic. They live under cover in the sailing dinghy on the aft cabin.

I've taken Doc's advice and junked the two UV-degraded cans and will replace them with new ones. Thanks.

-- Edited by Marin on Sunday 21st of November 2010 10:40:55 PM

 

[jleonard]

The mechanic at our marina went to several ethanol in the fuel classes over the past few years, mainly sponsored by Mercury.
He told us to always cover the dinghy fuel tank as the sun's heat helps degrade the gas faster.
So now I have 2 reasons to heed his advise. I hadn't ever considered the detrimental effect*on the plastic itself.
Thanks.
Jay

 

[FF]

Most nautical Flea markets still offer metal tanks at a fair price, stock up!