My woodstove's smoke pipe has 13 joints in it before entering the
chimney, could this thin wall steel be miged or would tig be a must.
Is there any other way to seal these joints? When it is very windy out
I get small rings of smoke puffing out of each joint, the flue is
above my peak, I have tried with /withought the rain cap and I now
have a "whirlybird" on top which is suposed to aim downwind and cause
a venturi to aid in draft but I am still getting the back draft. Also
it only seems to happen when I have the combustion air inlet is turned
down low. Thanks for any help.

I know this doesn't exactly answer the question you asked, but----
13 joints is a lot of joints for a wood heat system. If there are any
bends in all that "jointery" you are loosing a lot of draft. You need
at least 0.05" water column of draft for good operation and then you
wouldn't see the puffing. Get a cheap draft gage and check it out.
If you DO weld all that pipe together, how will you get it apart to
clean it? You know, you will have to clean it from time to time
because you will get creosote deposits in it. They will create a
chimney fire sooner or later. Not a good thing seeing the red glow work
its way up the pipe.
How high is the total height above the peak? Needs to be at least
2 feet, but there can't be any downdrafts from nearby trees, buildings, etc.
Maybe even need to relocate the stove to eliminate bends. One 90
degree bend costs you a lot of draft. Making that bend in 2 45's
doesn't help much.
If you do have a draft problem, better to install a suction fan in
the pipe.

heated with wood for 25 years,
Pete Stanaitis
------------------------------------


mark wrote:
My woodstove's smoke pipe has 13 joints in it before entering the
chimney, could this thin wall steel be miged or would tig be a must.
Is there any other way to seal these joints? When it is very windy out
I get small rings of smoke puffing out of each joint, the flue is
above my peak, I have tried with /withought the rain cap and I now
have a "whirlybird" on top which is suposed to aim downwind and cause
a venturi to aid in draft but I am still getting the back draft. Also
it only seems to happen when I have the combustion air inlet is turned
down low. Thanks for any help.

Might be a silly thought, but, do you have the pipe sections aimed in the
right direction?
The lower pipe should enter inside the pipe above it to help with creosote
buildup and
air leaks.

--
Peter DiVergilio
Most of the money I've wasted was mostly spent trying to impress people who
were never going to like me anyway!

On Jan 23, 12:38*am, spaco wrote:
I know this doesn't exactly answer the question you asked, but----
13 joints is a lot of joints for a wood heat system. *If there are any
bends in all that "jointery" you are loosing a lot of draft. * You need
at least 0.05" water column of draft for good operation and then you
wouldn't see the puffing. *Get a cheap draft gage and check it out.
* * If you DO weld all that pipe together, how will you get it apart to
clean it? * You know, you will have to clean it from time to time
because you will get creosote deposits in it. *They will create a
chimney fire sooner or later. *Not a good thing seeing the red glow work
its way up the pipe.
* * How high is the total height above the peak? * Needs to be at least
2 feet, but there can't be any downdrafts from nearby trees, buildings, etc.
* *Maybe even need to relocate the stove to eliminate bends. *One 90
degree bend costs you a lot of draft. * Making that bend in 2 45's
doesn't help much.
* *If you do have a draft problem, better to install a suction fan in
the pipe.

heated with wood for 25 years,
Pete Stanaitis
------------------------------------



mark wrote:
My woodstove's smoke pipe has 13 joints in it before entering the
chimney, could this thin wall steel be miged or would tig be a must.
Is there any other way to seal these joints? When it is very windy out
I get small rings of smoke puffing out of each joint, the flue is
above my peak, I have tried with /withought the rain cap and I now
have a "whirlybird" on top which is suposed to aim downwind and cause
a venturi to aid in draft but I am still getting the back draft. Also
it only seems to happen when I have the combustion air inlet is turned
down low. Thanks for any help.- Hide quoted text -

- Show quoted text -

All these joints are in a 3' span. The pipe goes up 2' from the stove
and bends 90 into the chimney but it has to offset about 6". I used 2
90 degree elbows that are each made up of 3 sections that can rotate.
These are common elbows sold everywhere, the only other option are the
corrigated type which will not work for me. There is an adapter to go
from the 6" pipe to the 7" flue entrance. If I do weld it all together
I can still take the whole unit off as one piece. Where would I go
looking for a cheap draft gage. Also I should mention my house is
surrounded by tall (= to house height) spruce trees but they are about
50-100' away in all direction. The front of the house is on the water
and there are a few tall trees there. The smoke sometimes comes right
down to the ground.

Might be a silly thought, but, do you have the pipe sections aimed in the
right direction?
The lower pipe should enter inside the pipe above it to help with creosote
buildup and
air leaks.

That's backwards as far as my experience shows, and I've seen the same
woodstove set up both ways. The upper pipe should go inside the lower
so that condensing smoke (liquid creosote) continues to drip down
towards the stove firebox, and not out at the joints and onto the
floor. With a good draft, the direction shouldn't matter to the smoke
as the leaks shouldn't let smoke out but pull air into the pipe
instead, so the flow of creosote determines which way the flanges go.
If you need to control the smoke with the direction of the flanges,
then you don't have enough draft.

As far as the original poster goes, could you put an extension on the
chimney to get more height? Maybe your chimney needs a liner--a
chimney too large for your stove can cause as many draft issues as one
too small. Most chimney sweeps can install stainless liners in about
a day, or less. Also, consider a draft damper, like the oil furnaces
use. If you have enough draft except when you shut the stove way
down, it will allow enough airflow to pull the smoke along without it
having to go through the stove. I seem to recall it takes ten times
as much air for draft to move the smoke than you actually need to burn
the fuel, but I might be mis-remembering.

Are you using all the elbows to get nice vertical and horizontal runs
for your flue? Consider reducing the number of joints by running the
pipe at an angle instead. Most of the elbows can be adjusted to
smaller angles by rotating the sections, which might allow you to use
fewer elbows.

You also might have too much stove for your space--remember a
woodstove is basically a space heater, not a whole house heater. If
you have to turn it way down to stand being in the room, you're not
getting good combustion and making too much smoke. A smaller stove
might let you actually run it with enough air to burn clean and not
drive you out of the room. You can only move so much heat to other
rooms with fans and the like.

--Glenn Lyford

On Jan 22, 10:33*pm, mark wrote:
...When it is very windy out
I get small rings of smoke puffing out of each joint, the flue is
above my peak, ... Also
it only seems to happen when I have the combustion air inlet is turned
down low. Thanks for any help.

I've been monitoring and tweaking my wood stove for over 20 years and
almost have it figured out.

The flue temperature above my stove needs to be at least 200F on a
magnetic stack thermometer. This is probably the most important point.
I also live where the wind can blow the smoke straight down. It won't
blow back into the house if the stack is hot enough.

The stove is a copy of a good airtight Jotul but it misbehaves like
yours if set for slow "cigarette burn". I arrange the wood so the
incoming air has a clear path at least half way down the bottom center
and the wood burns full length. It runs happily like this on three or
four fist-diameter pieces of oak an hour.

There's a mirror outside showing the top of the chimney. I set the
draft opening as small as possible without visible smoke, which
depends on outdoor temperature, and then vary the stoking rate for
more or less heat. I made a gauge like a step drill to set the draft
opening consistently. Right now it's at 3mm X 20mm at the bottom and
about twice that for secondary smoke-burning air above. Originally
both were equal.

My stove wants at least 0.08" of draft, 0.12" is better, 0.15" when
the wind comes down off Hudson's Bay. (I found a surplus Magnehelic
vacuum gauge cheap) You can make a draft gauge out of a U of clear
plastic tubing with colored water in it, fastened to a board. Tilt the
board to rise 1 inch in 10 and the distance between the two ends of
the liquid will be 10X the draft in inches of water. Once you know how
hot to run the stack you don't need the draft gauge.

Jim Wilkins

Interesting concept.

My wood stove was a single wall unit that left the stove and went up 30'.
(about 10 meters). It was bottom pipe inside top pipe. So the top slides
over the lower one in the stack up.

I never had problems with it for more than 17 years.
I always cleaned it from the top - and so did my sweeper. The brush
is long on extensions. Hotels and large homes have very long ones.


Now for the flow issue - two 90 degrees - that is tough on flow!
I think IIRC, that is 1/4 the normal flow rate.

I might have gone stainless and with bends.

Why not an insert ?

Martin

Martin H. Eastburn
@ home at Lions' Lair with our computer lionslair at consolidated dot net
TSRA, Endowed; NRA LOH & Patron Member, Golden Eagle, Patriot's Medal.
NRA Second Amendment Task Force Charter Founder
IHMSA and NRA Metallic Silhouette maker & member.
http://lufkinced.com/


wrote:
Might be a silly thought, but, do you have the pipe sections aimed in the
right direction?
The lower pipe should enter inside the pipe above it to help with creosote
buildup and
air leaks.

That's backwards as far as my experience shows, and I've seen the same
woodstove set up both ways. The upper pipe should go inside the lower
so that condensing smoke (liquid creosote) continues to drip down
towards the stove firebox, and not out at the joints and onto the
floor. With a good draft, the direction shouldn't matter to the smoke
as the leaks shouldn't let smoke out but pull air into the pipe
instead, so the flow of creosote determines which way the flanges go.
If you need to control the smoke with the direction of the flanges,
then you don't have enough draft.

As far as the original poster goes, could you put an extension on the
chimney to get more height? Maybe your chimney needs a liner--a
chimney too large for your stove can cause as many draft issues as one
too small. Most chimney sweeps can install stainless liners in about
a day, or less. Also, consider a draft damper, like the oil furnaces
use. If you have enough draft except when you shut the stove way
down, it will allow enough airflow to pull the smoke along without it
having to go through the stove. I seem to recall it takes ten times
as much air for draft to move the smoke than you actually need to burn
the fuel, but I might be mis-remembering.

Are you using all the elbows to get nice vertical and horizontal runs
for your flue? Consider reducing the number of joints by running the
pipe at an angle instead. Most of the elbows can be adjusted to
smaller angles by rotating the sections, which might allow you to use
fewer elbows.

You also might have too much stove for your space--remember a
woodstove is basically a space heater, not a whole house heater. If
you have to turn it way down to stand being in the room, you're not
getting good combustion and making too much smoke. A smaller stove
might let you actually run it with enough air to burn clean and not
drive you out of the room. You can only move so much heat to other
rooms with fans and the like.

--Glenn Lyford

On Wed, 23 Jan 2008 08:19:33 -0800 (PST), wrote:
Might be a silly thought, but, do you have the pipe sections aimed in the
right direction?
The lower pipe should enter inside the pipe above it to help with creosote
buildup and
air leaks.

That's backwards as far as my experience shows, and I've seen the same
woodstove set up both ways. The upper pipe should go inside the lower
so that condensing smoke (liquid creosote) continues to drip down
towards the stove firebox, and not out at the joints and onto the

exactly!

And if there does happen to be a chimney fire, that liquid creosote will
be flaming liquid creosote and you really want it to stay contained.

With double-wall or triple-wall pipe, just make certain the inner pipe
is oriented so liquid flowing down the chimney cannot run out.

floor. With a good draft, the direction shouldn't matter to the smoke
as the leaks shouldn't let smoke out but pull air into the pipe
instead, so the flow of creosote determines which way the flanges go.

Yup.

If you need to control the smoke with the direction of the flanges,
then you don't have enough draft.

Sounds that way. Another possiblity might be a tight house -- negative
pressure inside can cause poor draft.

You also might have too much stove for your space--remember a

Yes. My last place I put in the smallest stove cosmetically acceptable
to SWMBO. It was a new house, and easy to overheat. During one of
those "it's too hot in here" moments I found out the draft worked a lot
better with a window cracked open just a bit.

sdb
--
What's seen on your screen? http://PcScreenWatch.com
sdbuse1 on mailhost bigfoot.com

You guys are absolutely nuts! Under _NO_ circumstance should
there
ever be liquid creosote in your smoke pipes! Jeezz......
phil kangas

The right of the people to keep and bear
arms shall not be infringed.


"sylvan butler"
wrote in message
rnal...
On Wed, 23 Jan 2008 08:19:33 -0800 (PST),
wrote:
Might be a silly thought, but, do you have the pipe
sections aimed in the
right direction?
The lower pipe should enter inside the pipe above it to
help with creosote
buildup and
air leaks.

That's backwards as far as my experience shows, and I've
seen the same
woodstove set up both ways. The upper pipe should go
inside the lower
so that condensing smoke (liquid creosote) continues to
drip down
towards the stove firebox, and not out at the joints and
onto the

exactly!

And if there does happen to be a chimney fire, that liquid
creosote will
be flaming liquid creosote and you really want it to stay
contained.

With double-wall or triple-wall pipe, just make certain
the inner pipe
is oriented so liquid flowing down the chimney cannot run
out.

floor. With a good draft, the direction shouldn't
matter to the smoke
as the leaks shouldn't let smoke out but pull air into
the pipe
instead, so the flow of creosote determines which way
the flanges go.

Yup.

If you need to control the smoke with the direction of
the flanges,
then you don't have enough draft.

Sounds that way. Another possiblity might be a tight
house -- negative
pressure inside can cause poor draft.

You also might have too much stove for your
space--remember a

Yes. My last place I put in the smallest stove
cosmetically acceptable
to SWMBO. It was a new house, and easy to overheat.
During one of
those "it's too hot in here" moments I found out the draft
worked a lot
better with a window cracked open just a bit.

sdb

"Phil Kangas" fired this volley in news:fntvqe$t3e
:

You guys are absolutely nuts! Under _NO_ circumstance should
there
ever be liquid creosote in your smoke pipes! Jeezz......
phil kangas

Well, not liquid creosote, Phil, but water mixed with creosote and other
soluble combustion products, yes.

Until the pipe heats up enough, it acts just like any other condensor,
and in my experience they ALL drip a little (preferably into themselves,
not out) during initial fire-up.

LLoyd

"Lloyd E. Sponenburgh" lloydspinsidemindspring.com wrote
in message
. 3.70...
"Phil Kangas" fired this volley in
news:fntvqe$t3e
:

You guys are absolutely nuts! Under _NO_ circumstance
should
there
ever be liquid creosote in your smoke pipes! Jeezz......
phil kangas

Well, not liquid creosote, Phil, but water mixed with
creosote and other
soluble combustion products, yes.

Until the pipe heats up enough, it acts just like any
other condensor,
and in my experience they ALL drip a little (preferably
into themselves,
not out) during initial fire-up.

LLoyd

From what I've seen on this subject of creosote dripping the
problem is
the 'automatic dampers' used. They allow the air intake
plate to completely
close off the air intake hole! This is not acceptable and is
the root cause of
the situation which in my opinion is very serious indeed and
must be taken
care of immediately. The simplest fix is with a welding rod
with one end
bent into a hook and you hang in on the intake hole so the
plate can never
close completely. None of my stoves have ever dripped
'liquid', ever.
The guy with 13 joints has a real problem!
phil kangas