"The Natural Philosopher" wrote in message
...
Donnie wrote:
Hey all, just filled a tub in the back yard with a caustic soda mix to
clean up an old 2 stroke exhaust but it's just occurred to me that
there will be approximately 3 or 4 gallons of caustic soda / rust mix
to dispose of.

I am assuming I can dump it down the outside drain as caustic soda can
actually be used to clean drains?
yes. Or mix oil with it to form the sort of detergent the drains cope with
every day.

With enough water in it, its not that evil a mix.



You actually have to boil vegetable oil or animal fats with caustic for some
time for specification. and it is not possible for mineral oils or paraffin
waxes:

http://en.wikipedia.org/wiki/Saponification
http://en.wikipedia.org/wiki/Unsaponifiable

In testing oils, one key test of purity is its 'sap value'.

When oils are emulsified they are actually more polluting than when they are
separated out from the water environment: the difference would be like you
walking through a puddle of oil as opposed to having it sprayed at you in a
mist that you could not avoid breathing in.

S