I mentioned to Princeton rink manager Jeff Graydin tonight about the discussion
here on zambonis.
 
  He said VERY definitively (and with some obvious knowledge of the
physics/chemistry involved) that it was NOT because of mixing the new water
with the shavings.
   He said the zamboni has a razor-sharp blade that scrapes the ice smooth, and
scoops up the shavings.
 
   What the hot water does, as some people have mentioned, is release the
extranneous oxygen so the ice is more dense and "hard" making it better for
skating.  This is the reason hot water is used.
   He did say he knew that hot water freezes faster, but that that was not the
reason it was used, nor was it for creating a blend with the old ice.
 
   He also said the water is between 160-180 degress farenheit, and the zamboni
does NOT heat the water.  It is already heated when "poured" into the zamboni.
    Finally, he said there is a chemical mixture called "Jet Gloss" that is put
on the ice once a week, particularly after a tough practice.  The effect is the
same as using hot water (in that it releases the oxygen), but it gets there by
different chemical methods.
 
  Sounds pretty definitive.  I thanked him greatly for making me look good
here<G>!   Assuming no one disagrees, that is.
 
                                      AW