[Shop-talk] battery operated soldering irons

[David Scheidt]

On Fri, Jun 18, 2010 at 7:10 PM, Randall <tr3driver at ca.rr.com> wrote:
>> Ok - so whats the difference between Butane and Propane anyway
>
> Not a whole lot, but they have slightly different properties. B Butane is
> C4H10, while propane is C3H8. B Butane has a lower boiling point, so works
> even in extremely cold weather, while pure propane can have problems when
> it's really cold.

butane doesn't work below ~freezing.  Boiling point is, as I recall,
just below 0 C.  Iso-butane boils about -10 C.  (most commercial
butane fuels are a mixture of the two, typically 80% butane 20%
iso-butane, but the mix varies from supplier to supplier.  (Iso-butane
is a bit more valuable than butane; it's used as a refrigerant, and as
feedstock in some chemical reactions).  Propane has a boiling point of
about -40.  (Commercial propane is a mix of propane, butane,
iso-butane, and a others; ratios vary wildly.  Most US propane is
pretty much propane.  )

Butane has about 20% more energy per kilogram than propane, and a bit
less than natural gas.

--
David Scheidt
dmscheidt at gmail.com