Oil into silicone?

[AF 70]

I use a galvanized container with a flex spout for adding oil to power trol, engine etc. It's kept in a plastic bag when not in use. The way it's "designed", you can't get about two tablespoons of oil out of it. This settles into the various seams, welds etc. The other day I discovered that the "oil" in the seams wasn't oil any more. It had set up into a stretchy substance resembling a thin, brown bead of silicone sealer. I dug it out and it came out pretty cleanly in strips. I generally use the can for 10-40 detergent oil. What's going on here? Can this happen inside the tractor? What about in 2-5 gallon containers? This has got me a little bugged!!!
 

[old]

Sounds like the oil is eating the plastic bag and when it does it in turn forms a plastic/oil mix that is what you have now. No the oil does not do that in the engine unless of course you have that plastic in the engine
 

[Bob Harvey]

"It's kept in a plastic bag when not in use"
 

[old]

Yes and that is where he said he found what he did and no matter what it is hard to get every last drop of oil out os something like that so yep the plastic bag and oil do not agree with each other