Extra heat? That is the wood burning in addition to the wax.
All wood has the same energy? Oh wow, think of all the time I spent
messing with the oak rather than the aspen... See that was my
problem, I thought I was getting more heat from the oak than I did
from the softwoods all those years.
I thought the hardwood burning along with the wax did the trick for
the extra heat. The only person I know (from a list) who has used one
said it worked great in the car that had run off the road in a snow storm.
It  is  one  of  those  emergency things  you  keep
in  back,  with  any  luck  you  will  never  have  to  find  out  if
  it  gives  enough  heat  to  keep  you  alive  thru  the  night.
<Shrug> Next time you're messing with a presto log give it a try and
let us know if it works.

Rob
becida@comcast.net

At  10/30/2009 08:25 PM,Mike S wrote:
>At 10:19 PM 10/30/2009, Rob wrote...
>>At  10/30/2009 06:32 PM, Mike S wrote:
>>>Sounds much like one of those artificial fire logs. You could
>>>probably just get one of those, and cut off what's needed, as needed.
>>
>>This is a candle gives off 'extra' heat not a presto log.
>
>Where does this "extra" heat come from? A special high-calorie wax?
>Dry wood is around 6K BTU/lb., whether hardwood or softwood.
>
>Cutting off a few inches of a artificial log, and stuffing it around
>a wick in a can (the logs use a soft wax, and crumble easily), seems
>much easier than mixing melted paraffin wax and woodchips. It also
>allows one to replenish the candle when needed (a log and some wick
>are all that's needed). Probably cheaper than paraffin, too.