[TheForge] Re: coal forge flues

[Bob Willman]

	We have a new side draft forge at the local museum with 12" single
wall stainless stack through the roof - total length about 12-14 feet. You
can lay your bare hand on the stack above the forge for a short time with
out damage to the skin. 
 	My forge at home has 6" triple wall stainless - it was free -
straight up from the firepot with a square hood since 1988 and I have no
problems with the inspector. There is nothing in the code book about forges.



Bob Willman
Bowling Green, Ohio
The Eagle's Anvil
WB8NQW

-----Original Message-----
From: theforge-bounces at mailman.qth.net
[mailto:theforge-bounces at mailman.qth.net] On Behalf Of Marc Godbout
Sent: Monday, January 14, 2008 7:15 PM
To: Sponsored by ABANA
Subject: Re: [TheForge] Re: coal forge flues

I think there's still a problem with a hot flue that isn't related to
creosote and chimney fires. The flue itself will still get hot during normal
operation. A fire inspector would be concerned that the flue doesn't get hot
enough to start combustion in the wall or ceiling/roof that it's going
through.

--Marc

On 1/14/08, Mike Spencer <mspencer at tallships.ca> wrote:
>
> Bruce wrote:
>
> > What you want to do is convince him that the forge flue will never 
> > get as hot as a wood stove.
>
> In particular, neither a coal forge nor a propane forge will coat the 
> inside of the flue with "creosote" -- highly inflammable wood 
> distillates that are volatile at stove-fire temps and solid at lower 
> temps.  The really disastrous flue fires arise from running a "normal"
> wood fire and allowing a heavy build-up of creosote to accumulate, 
> then running a hotter that usual fire that ignites the accumulation 
> near the stove.  Then the flue fire propagates rapidly along the 
> creosote in the rest of the flue until the whole thing is a 
> self-fueled blowtorch, spewing chunks of flaming, coke-like carbon and 
> heating the flue red hot or (depending on the available air inflow) 
> hotter.
>
> Doesn't happen with a forge flue.
>
> If you let the flue fill with heavy coal smoke during start-up, you 
> can have a short-duration "event" when the smoke ignites and a 
> fireball flashes up the flue.  If the joints (or mortar) in the  flue 
> aren't tight, the overpressure during this event can blow tiny sparks 
> of burning soot out through any gaps.  But no sustained, self-fueled 
> blowtorch effect.
>
>
> FWIW,
> - Mike
>
> --
> Michael Spencer                  Nova Scotia, Canada       .~.
>                                                            /V\
> mspencer at tallships.ca                                     /( )\
> http://home.tallships.ca/mspencer/                        ^^-^^
> _______________________________________________
> Manage membership or unsubscribe at:
> http://mailman.qth.net/mailman/listinfo/theforge
> theforge mail list group photo site is http://www.photoaccess.com
> Login:  blacksmithblacksmith at hotmail.com
> password:  anvil
> ___________
>
>
>
_______________________________________________
Manage membership or unsubscribe at:
http://mailman.qth.net/mailman/listinfo/theforge
theforge mail list group photo site is
http://www.photoaccess.com
Login:  blacksmithblacksmith at hotmail.com
password:  anvil
___________