Oil Leakage

[Chipchopper]

I went in my garden shed this morning and was surprised to see engine oil dripping down from a high shelf, where I had several bottles of oil stored.
A couple of the plastic bottles were many years old but it was impossible to see which bottles were leaking due to the fact that the whole shelf was drenched in oil, including the bases of the bottles.
I removed and disposed two of the oldest bottles, assuming it must be them-----so my question is, why did the bottle/s suddenly spring a leak ??.
The weather was cool and sunny and frosty, first thing but nothing too extreme, so I wondered if rodents or something else may have caused the leak.

[IJKLM]

It depends a bit on the plastic and the oil.
There are many different types of plastic - polyethylene, polypropylene, ABS and so on.

Many of these use additives called plasticisers to make them a bit softer and more pliable.

Mineral oils (and synthetic oils) can dissolve the plasticisers and also some low-density plastics.

WHat I suspect is ging on is that over time, the oil has leached plasticisers out of the plastic and degraded the materials to the point where the plastic gave way.

It's a very slow, gradual process, so the specific weather or temperature on the day of the failure is not that relevsnt - though he process will speed up at higher temperatures.

Probably, if you can recover the offending bottle, you'll find it is more brittle than the top of the bottle, for example.

Hope it helps

[gingejbee]

I'm quite interested in why you have several bottles of engine oil stored in your garage.....no, really interested!
And, for many years, too.......

[tonyav]

I have to ( several bottles of oil ), gathered over the years. Different cars that I have owned have used different oil specs.

[gingejbee]

^^^but why keep oils that you no longer need?

[tonyav]

May have another car that uses one of the oils that I already have.

[Chipchopper]

I'm kinda leaning towards a sudden change in temperature as caused some sort of reaction but I'm still mystified.

[Chipchopper]

Why several bottles of oil in my shed ? simple some for the car, some for the mower and garden machinery, plus some used sump oil for keeping tools rust free and good condition and come to think of it a bottle what someone gave to me when they moved house.

[diddlydo]

Take the whole lot to your local tip and start again.

[Old_Geezer]

I suppose everything degrades in it's own time.
I had a similar issue with some Jeyes Fluid tins, but separating them and checking after a while told me which was the leaky one.

[TonyV]

plastic containers have probably degraded over the years and last cold snat finished them of