How to seal stove pipe

[tsh2002]

Hello:
Today we fired up a new stove for the first time, with a new chimney install. We have the BK Ashford 30, so the stove pipe coming up and to the thimble is the standard 6 inch single wall black pipe. We have the outside air kit installed as well to ensure no flow issues. Today I noticed that if the wind picked up outside, there was a whistling noise in one of the joints of the 6" pipe in one of the elbows. When the wind stopped, the noise stopped. The draft is good as nothing comes in to the room, so it appears to be pulling air in as intended. I was just wondering is there a product I could use to seal the noisy seam? I can pretty much pinpoint exactly where it is coming from which seems to be one of the seams of the elbow, and I suspect it is a super tiny gap just enough to make the noise. I know they make hi temp silicone caulk but it seems to be good only up to 500 degrees. I was hoping for some sort of caulk but so far I don't see anything that seems to be for this type of issue.

Thank you!

 

[webby3650]

Is there a reason you didn’t go with the recommended double wall stove pipe? Furnace cement is the only thing that’ll hold up to those temps. Get some quality 22 gauge pipe if you’re gonna run single wall, it’s uniform and doesn’t have the gaps that snap lock has.

 

[tsh2002]

Is there a reason you didn’t go with the recommended double wall stove pipe? Furnace cement is the only thing that’ll hold up to those temps. Get some quality 22 gauge pipe if you’re gonna run single wall, it’s uniform and doesn’t have the gaps that snap lock has.

I just figured I'd get more radiant heat in the room with the single wall. I used 24 gauge black 6" stove pipe from Menards. In my case I wanted to put in two 45 degree elbows and used the adjustable elbows to do that. I do see they have the furnace cement in tubes, I might look at that or see if it's worth swapping it out at some point. It's a pretty minor issue but annoying at times.

 

[webby3650]

I just figured I'd get more radiant heat in the room with the single wall. I used 24 gauge black 6" stove pipe from Menards. In my case I wanted to put in two 45 degree elbows and used the adjustable elbows to do that. I do see they have the furnace cement in tubes, I might look at that or see if it's worth swapping it out at some point. It's a pretty minor issue but annoying at times.

The flue needs the added heat to operate efficiently. Double wall pipe should be used with a blaze king.

 

[Hoytman]

The flue needs the added heat to operate efficiently. Double wall pipe should be used with a blaze king.

I agree with the above. Use double wall pipe.

For additional information I’ve been using this and really like it for sealing single wall. Cleans up easily with water. Comes off easy at end of season to remove pipe. Holds up great.
(broken link removed)

It has a “800*F continuous” rating.

 

[stoveliker]

The reason for needing double wall is that you bought a stove that is so efficient that not much heat can be extracted from the pipe without negative consequences.
Especially when you run it low, you are close to (creosote) condensation temperatures, so you should keep as.much heat.in there as.possible.

 

[tsh2002]

OK thank you for the replies. FYI our flue is insulated from the thimble and onward, I didn't know that the pipe near the stove could have any creosote issues since it's completely indoors and the BK manual says to use either single or double wall. I'll look in to the double wall pipe, since it's a fairly easy swap compared to other things. And thank you for the hi temp sealant, I had searched and did not see that one. Thank you!

 

[RockyMtnGriz]

For additional information I’ve been using this and really like it for sealing single wall. Cleans up easily with water. Comes off easy at end of season to remove pipe. Holds up great.
(broken link removed)

It has a “800*F continuous” rating.

Another thank you for the sealant mention. I hadn't seen that and I'm going to have to try some. I've been using silicone liberally, and it has been working great, but depending on the situation, it can be hard to remove.

Strange that Rutland gives this latex formula a higher temp rating than their silicone products. That sorta turns what I know of the world upside down!

 

[BKVP]

Just to clarify:

All wood heaters are tested using single wall black stove pipe to establish clearance to combustibles. This is an industry wide practice at safety test labs.

On pages 2, 9, 10 and 35 of the AF30.2 manuals we recommends the use of double wall stove pipe. Page 10 does reference the use of single wall and double wall, again because that is how they are tested.

As most of you may recognize, many stove companies are now making catalytic units and are recommending the use of double wall stove pipe.

BKVP

 

[tsh2002]

Just to clarify:

All wood heaters are tested using single wall black stove pipe to establish clearance to combustibles. This is an industry wide practice at safety test labs.

On pages 2, 9, 10 and 35 of the AF30.2 manuals we recommends the use of double wall stove pipe. Page 10 does reference the use of single wall and double wall, again because that is how they are tested.

As most of you may recognize, many stove companies are now making catalytic units and are recommending the use of double wall stove pipe.

BKVP

Thank you BKVP! I did not catch those references to the double wall pipe in the manual, so thank you for pointing that out and for the explanation, very helpful. Today I ordered the double wall pipe and will be swapping it out as soon as it gets here in a week or two hopefully. In the meantime, just learning how the stove runs but we absolutely love it.

 

[mellow]

DBL wall should cure that whistle as well without putting chemicals on it. Since this is new to you I would highly recommend putting an alarm system on the exhaust pipe, even old timers will forget to close the bypass sometimes and turn down the air.

Thermometer for Stove Pipe,Chimney,Outdoor Wood Boiler,w/ Alarm Thermometer for monitoring temperature on stove, chimney, or outdoor wood boiler [AT200CHIM] - $74.99 : Auber Instruments, Inc., Temperature control solutions for home and industry

Thanksgiving sale ends on 12/1/2024! This thermometer kit can be used for monitoring the temperature in stove pipes, chimneys, and outdoor wood boilers. This thermometer reads a thermocouple probe, shows the temperature on its red LED display, and makes a buzzing sound when temperature rises...

www.auberins.com

 

[kennyp2339]

Thin rope gasket material shoved between the stove collar and smoke pipe will make tight seal and handle the heat, the stove cement or high temp silicone makes a mess

 

[Hoytman]

This Rutland latex sealant is good to 800F and is water cleanup and does NOT make a mess.

Seal It Right® Flexible Latex Sealant

RUTLAND Seal It Right® Flexible Latex Sealant forms a non-permanent seal that expands and contracts. For metal, wood, plastic, masonry, and aluminum.

rutland.com

You can buy it at Tractor Supply. Stuff is great!

 

[tsh2002]

I've finally been able to get the double wall stove pipe (I ended up using Duravent DVL, seems like decent stuff) and installed it yesterday, will see how it goes.
But... when I removed the single wall pipe, there was some creosote already built up in it after running it about a month continuously 24/7 at its lowest setting. I know the single wall pipe is no good for this stove, but I am also curious if I might be adding to the problem, too. The BK book says to let the fire to "establish" on every reload and says it takes about 20-30 minutes, then turn the dial back down. However I've been waiting about 5-10 minutes or so and turning it down, as the fire seems to be going pretty good to me and the gauge is already in the "active" zone. It does cause extra smoke but the temp gauge keeps going up and will usually settle around halfway in the "active" zone. Would it be better to purposely let the fire burn high for 20-30 minutes instead and could that help prevent any further creosote issues? Again, thank you as we are still beginners at this.

 

[stoveliker]

I turn down when all the (visible..) wood is black and the fire is going well. Indeed for my system that's sooner than 20 minutes.

It's important though (in my case) to dial down in steps. I take 5 minutes between steps and go from full bore (5 or 6 pm on the thermostat of my stove, where 6 pm is the highest) to 3 pm in two or three steps.

 

[BKVP]

We "dial down" to adjust for MC. That is variable. So visual inspection, like Stoveliker is the best way, not actual minutes.

BKVP

 

[tsh2002]

Hello again. I'm just following up as now that we are a few months in to our new setup, I recently discovered we've been getting a lot of buildup in our flue, mostly up near the top and around the rain cap. Attaching some pics. The cap had a 1/2" hardware cloth mesh that I just removed because it had a lot of buildup on it. I've started to clean the flue as well, everything shown in the pics is the dry crusty stuff so it comes off easy, but now the question is what should I do moving forward. I started double checking the wood we are using, it's been under a lean-to and mostly out of the weather for about 2 years, some of it has had a little rain/snow on it that blows in, however all readings are coming back between 8-12 mostly after splitting it in half, a piece here and there is up to about 16. The BK manual says to stay under 20, and obviously the lower the better. The second thing is I'm wondering if I should be running the stove hotter on reloads. Typically I let it get down to the coals (needle is just inside the "active" zone), then open the bypass wait a couple minutes, reload, close the bypass and run it on high for a few minutes until the fire is going pretty good then dial it back down. Usually when I dial it down the needle is 1/2" or so just inside the "active" zone, and the stove will run and eventually get about halfway in to the "active" zone then stabilize there for many hours. Right now is also our shoulder season, too, temps have been hovering between 20-50 degrees outside.

Open to any thoughts on this of what we can do to prevent this from happening again. For example I'm probably going to get a bigger mesh and toss this 1/2" stuff. Thank you very much as this forum has been a super help.

 

[BKVP]

Getting rid of screen will help. Honestly, your wood, unless stored indoors, is likely higher in mc than your meter is reading.

Yes, run the stove on high for about 30 minutes after each reload. I would make certain you are also lock the bypass.

Give that chimney a good cleaning and then check it more often...

BKVP

 

[tsh2002]

Getting rid of screen will help. Honestly, your wood, unless stored indoors, is likely higher in mc than your meter is reading.

Yes, run the stove on high for about 30 minutes after each reload. I would make certain you are also lock the bypass.

Give that chimney a good cleaning and then check it more often...

BKVP

Thank you BKVP! I am certain the bypass is locked tight always. But yes, I will definitely be getting this wood situation improved and run the stove hotter just as you said. Will get this cleaned and see how it goes from there.

 

[stoveliker]

The bypass does cam over (lush through a bit of resistance)?

The wood should be measured at room temp, so best take a split inside for 24 hrs, then resplit and measure.
Make sure the pins are deep into the wood, and that they are parallel to the grain.

I do think that charring the load a bit longer is useful. You could also reload slightly earlier so that when you open the bypass a bit more heat goes up, and the moisture from the charring phase has less chance to condensed and capture smoke.


How tall is the chimney and is it inside?

A tall chimney may not only have a cooler top but also decrease the residence time of the gases in the cat (thus allowing more smoke through).

 

[EbS-P]

Hello again. I'm just following up as now that we are a few months in to our new setup, I recently discovered we've been getting a lot of buildup in our flue, mostly up near the top and around the rain cap. Attaching some pics. The cap had a 1/2" hardware cloth mesh that I just removed because it had a lot of buildup on it. I've started to clean the flue as well, everything shown in the pics is the dry crusty stuff so it comes off easy, but now the question is what should I do moving forward. I started double checking the wood we are using, it's been under a lean-to and mostly out of the weather for about 2 years, some of it has had a little rain/snow on it that blows in, however all readings are coming back between 8-12 mostly after splitting it in half, a piece here and there is up to about 16. The BK manual says to stay under 20, and obviously the lower the better. The second thing is I'm wondering if I should be running the stove hotter on reloads. Typically I let it get down to the coals (needle is just inside the "active" zone), then open the bypass wait a couple minutes, reload, close the bypass and run it on high for a few minutes until the fire is going pretty good then dial it back down. Usually when I dial it down the needle is 1/2" or so just inside the "active" zone, and the stove will run and eventually get about halfway in to the "active" zone then stabilize there for many hours. Right now is also our shoulder season, too, temps have been hovering between 20-50 degrees outside.

Open to any thoughts on this of what we can do to prevent this from happening again. For example I'm probably going to get a bigger mesh and toss this 1/2" stuff. Thank you very much as this forum has been a super help.

View attachment 326483 View attachment 326484

Is the second pic looking down the chimney??

 

[tsh2002]

The bypass does cam over (lush through a bit of resistance)?

The wood should be measured at room temp, so best take a split inside for 24 hrs, then resplit and measure.
Make sure the pins are deep into the wood, and that they are parallel to the grain.

I do think that charring the load a bit longer is useful. You could also reload slightly earlier so that when you open the bypass a bit more heat goes up, and the moisture from the charring phase has less chance to condensed and capture smoke.


How tall is the chimney and is it inside?

A tall chimney may not only have a cooler top but also decrease the residence time of the gases in the cat (thus allowing more smoke through).

Yes the bypass door is tight and when it locks it does have some slight resistance, and I did verify this before I installed the stove pipe as well to the top of the stove, the gasket is there at the flap and the seal looked good.

The chimney is about 16ft from the thimble to the top.

 

[stoveliker]

Good.
Assuming the bypass gasket is okay, then the only thing I can think of is what BVKP said: char longer.

 

[tsh2002]

Is the second pic looking down the chimney??

Yes, from the top down. That severe buildup is only in the top several feet, once past that part the flue looked decent but I will confirm once I do the full cleaning.