[TheForge] a lot of unimpressive BS

[Chris Worsley]

Tom,
I have never regretted a post made to this list. I can see why you 
regret yours.
My comment had nothing to do with the physics of  smoke and/or gasses as 
they leave a forge.
I was only concerned with your statement that hot air does not rise.

The next time you visit a shop as you describe below, have the user 
light a loosely packed ball of newspaper to preheat the air in the 10" 
dia. pipe, and it will draw if it is long enough and not restricted by 
debris or roofline height. I have done this for more than 20 years in 
both straight flue hooded forges and side draft flues. Neither style 
confuses me.

No pearls of response expected Tom, since you are not interested in 
communicating with "swine" such as I. ;-)
I'm done.

Chris
Alexandria VA

>>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
>
>
>  
>