[TheForge] a lot of unimpressive BS

Sat Jan 3 21:32:02 2004

on 1/3/04 7:10 PM,
> From: Chris Worsley <[email protected]>
> To: [email protected]
> Subject: Re: [TheForge] hot air does not rise
> Reply-To: [email protected]
> The truth comes in simple words! Well said Dave, without a lot of
> unimpressive BS ;-) .  Thanks.
> Chris

>> Details, details, details.  It still boils down to warm/hot air rises,
>> cool air sinks.  Exhaust from a gas forge is warm/hot and will move
>> upwards, not towards the floor.  The mechanism of the action is moot.
>> It happens.  The CO and CO2 and the H2O and other byproducts of the
>> propane forge combustion will rise.
>> 
>> Dave Brown
>> Heritage Smithing
>> Green Bay, WI

Dear Chris and Dave,

My attempt at an explanation of the physics of gases was not meant to be a
criticism of Dave, or his shop, only a simple clarification of a very
commonly misunderstood phenomenon. Several times a year I have the
opportunity to demonstrate physics to elementary school students, and they
understand the difference right away. They go home and explain it to their
parents.

The reason that I bothered to comment in the first place was not merely to
pontificate "a lot of unimpressive BS" but in the hope that the information
could be understood and utilized, apparently I was mistaken.

I have visited many metalworking shops where a 6 foot diameter sheet metal
hood was placed directly over a gas or coal forge, and vented straight up
through a 10" dia pipe; and even though the forge directly below provided an
endless supply of "hot air", the hood failed to draw. The owners simply
couldn't understand why the shop was still smoky. The same goes for
fireplaces in modern houses.

The inverse of this is the "side-draft" flue, where smoke and flames from
the forge turn 90 degrees sideways before they go up the stack. I sincerely
hope that you never stumble upon one of these in action, it might confuse
you.

I almost always regret my postings to this list, and this is case is no
exception. "Pearls before swine", and all that. I shall pester you no more,
and please accept my sincere apologies for my rude intrusion into your
contented ignorance, 'twon't happen again.

Tom Troszak