"billh" wrote: (clip) too many variables and too many documented cases of
oily rags starting fire to take any chances at all with them.
^^^^^^^^^^^^^^
Bill, I certainly agree that it would not be wise to take chances by
allowing oily rags to lie around unattended. However, what I wrote was a
comment on a particular *alleged* incident. I am a mechanical engineer with
some background in heat transmission and combustion, both of which relate
to an understanding of spontaneous combustion. My training tells me that an
oily rag on a bench for a brief period will not have time, nor the right
conditions to heat up. If this were not the case, rags would start
smouldering while the person is IN the shop, even if the phone didn't
distract him/her. It would be such a common experience that most of us
would have witnessed it, and oily rags would be considered dangerous.

Still, what I wrote was full of weasel words like "likely to be untrue," and
"probably." I wouldn't want anyone to consider what I said as encouragement
to pile up oily rags. What you said is much safer than what I said.