Chinook 30 install

[WoodyIsGoody]

I have 12 feet of vertical 6" Selkirk DCC double wall pipe to reach my SS chimney. The tech guy at Selkirk said I would need a Selkirk DCC stove adapter to properly fit the flange on a Chinook 30 so I ordered one of those too. But it gets weird.

The double wall pipe fits the stove flange perfectly, nice and snug and it drops down far enough to use the three screw holes in the flange if I wanted to affix the double wall pipe directly to the flange. Very solid and air-tight feeling. But Selkirk says the outer wall must sit flat on the stovetop or the stove flange adapter is necessary. I believe the reason for that is so the weight of the outer wall is physically supported by more than the connection between the inner and outer pipes and the screws. But it might also be to limit the amount of air that can flow between the inner and outer walls.

Here's the weird part. The inner wall of the 6" stove adapter fits inside the stove flange and the outer wall rests on the top of the firebox but the inner pipe is not even close to being airtight within the flange. I cut a 22" inch long piece of 30 gauge steel I had laying around into a strip 2" wide and inserted it around the inside of the stove flange so it stays put by spring pressure. It goes around 1 1/4 times. But the stove adapter is still so loose I can still slip it inside the flange without disturbing the sheet metal! This will ruin my draft! Aren't stove pipe and stove flange sizes standardized? I've never run into this issue before.

What should I do?

 

[double-d]

I read the DCC installation, and it said the same thing..."Select a section of Double Wall Chimney Connector and place it over the stove collar. The outer wall of the connector should rest flat against the top surface of the stove..."
Not sure who you spoke to but, I usually call the Selkirk 800 669 3190 and talk to Price Grandy...seems to know everything about Selkirk

 

[kennyp2339]

OPTION 1

 

[WoodyIsGoody]

I read the DCC installation, and it said the same thing..."Select a section of Double Wall Chimney Connector and place it over the stove collar. The outer wall of the connector should rest flat against the top surface of the stove..."
Not sure who you spoke to but, I usually call the Selkirk 800 669 3190 and talk to Price Grandy...seems to know everything about Selkirk

Yes, I spoke with Price before I placed my order. I've left him a voice mail and am waiting for his return call.

 

[Rickb]

I have a sirocco 20 and my dbl wall stove pipe goes right onto my stove nice and tight. I am using no adaptor. It does not slide all the way to the top of the stove but it slips on about 1.5-2 inches.

 

[WoodyIsGoody]

I have a sirocco 20 and my dbl wall stove pipe goes right onto my stove nice and tight. I am using no adaptor. It does not slide all the way to the top of the stove but it slips on about 1.5-2 inches.

Yes, mine connects directly to the double wall pipe with a perfect fit as well. But the pipe manufacturer says this is only acceptable if the outer pipe rests on the stovetop. With Selkirk DCC pipe this would only be possible if the stove's flange was 1" or less high.

 

[begreen]

What is stopping the pipe from dropping all the way to the stove top? Is it the taper of the inner liner crimp or is there a bar or other obstruction inside the flue collar?

 

[WoodyIsGoody]

What is stopping the pipe from dropping all the way to the stove top? Is it the taper of the inner liner crimp or is there a bar or other obstruction inside the flue collar?

The double wall pipe only allows for an insert of about 1". Here's a photo of the bottom end of the extendable section that was damaged because the included screws were not affixed to the inside of the pipe when packaged by the manufacturer. The screws ended up at one end of the pipe box and, at some point during transport the box was positioned vertically and the thin pipe edge rested on the screws. You can see why it will only allow for 1" of insertion. Contrast that to the stove adapter in the next photo. Why the diameter of the inside pipe of the adapter is so much smaller than the other pipe sections, I have no clue.



And this is how I satisfy my need for fire while I'm currently stoveless:

 

[WoodyIsGoody]

I'm just waiting for Price at Selkirk to return my call. I left him a message early Friday but he must have had the day off.

 

[Highbeam]

I would not want to sacrifice a good seal at the stove. I would much rather skip the adapter if Price lets you. If you are forced to use the adapter then I might use a better brand or try and seal the collar with something, probably unsuccessfully.

 

[WoodyIsGoody]

I would not want to sacrifice a good seal at the stove. I would much rather skip the adapter if Price lets you. If you are forced to use the adapter then I might use a better brand or try and seal the collar with something, probably unsuccessfully.

I think it's a given that the seal at the stove has to be tight. Worst case scenario would be to have a metal fab shop cut and weld a support ring for the outer wall of the regular double wall pipe and return the stove adapter. But I'm hoping the stove adapter is just way, way out of spec. Don't all woodstoves that are designed for 6" stove pipe have flue collars with the same inside diameters?

 

[Highbeam]

Don't all woodstoves that are designed for 6" stove pipe have flue collars with the same inside diameters?

No! They don't. It should be a standard but it is not. And then there is the fact that the collar(on most steel stoves) is just welded on top of a hole cut into the stove top and some companies have such short collars that the tapered flue pipe has to interfere with the stove top inside the flue collar.

The only weird thing about your install is that the Selkirk pipe requires that the outer wall of the double wall rest on the stove top. If not for that requirement, I would highly recommend you go with plan A for a tight seal. I did in fact install the simpson double wall in this manner with my hearthstone heritage. It made a wonderful seal.

 

[begreen]

If not for that requirement, I would highly recommend you go with plan A for a tight seal. I did in fact install the simpson double wall in this manner with my hearthstone heritage. It made a wonderful seal.

That is also the way our DVL stove pipe is installed and it seals well. With just ~6 ft. of stove pipe above, screwed at the joints I am not worried about the weight, though I don't recall DuraVent having a requirement to sit on the stove top.

 

[WoodyIsGoody]

That is also the way our DVL stove pipe is installed and it seals well. With just ~6 ft. of stove pipe above, screwed at the joints I am not worried about the weight, though I don't recall DuraVent having a requirement to sit on the stove top.

Does the DVL pipe have vent holes so air can travel from pipe section to the next pipe section between the two walls? Or is the only venting out to the room at the top of each pipe section?

The manufacturer of the DCC pipe requires the top to be tight against the chimney adapter as well as the bottom against the stove top. Maybe this is to prevent the hot air between the double walls from flowing upwards due to natural convection? Air can migrate freely between sections but not out the top or in the bottom?

 

[WoodyIsGoody]

No! They don't. It should be a standard but it is not.

I noticed the inside of the stove adapter is tapered in three steps. Maybe the adapter is designed to be shortened to the appropriate taper to suit the diameter of the particular stove collar it needs to fit?

If so, what would be the best way to cut three inches off the bottom of the adapter? Given how the inner and outer walls are only supported at the top of the adapter, I don't think a hacksaw would work very well.

 

[Highbeam]

If so, what would be the best way to cut three inches off the bottom of the adapter? Given how the inner and outer walls are only supported at the top of the adapter, I don't think a hacksaw would work very well.

I have had the best luck cutting pipe with a die grinder fitted with a thin disc. It's noisy, and you need eye protection but you can cut precisely without distorting the surrounding metal. Cutting with tin snips always buggers up the metal. You can also tighten the taper of the stove pipe with a tool made for that, it looks like a pair of pliers.

 

[WoodyIsGoody]

I have had the best luck cutting pipe with a die grinder fitted with a thin disc. It's noisy, and you need eye protection but you can cut precisely without distorting the surrounding metal. Cutting with tin snips always buggers up the metal. You can also tighten the taper of the stove pipe with a tool made for that, it looks like a pair of pliers.

Thanks for that! I just found a 4" thin cutting disc for my angle grinder (it's made for SS). I forgot I even had this.

I think I need to use wood wedges/shims to support the inner pipe when cutting.

 

[begreen]

I have had the best luck cutting pipe with a die grinder fitted with a thin disc. It's noisy, and you need eye protection but you can cut precisely without distorting the surrounding metal. Cutting with tin snips always buggers up the metal. You can also tighten the taper of the stove pipe with a tool made for that, it looks like a pair of pliers.

One of my early jobs as a kid was tin knocking. I got lots of cuts at first. Cutting with tin snips is a skill. Done properly there will be a nice clean edge with no fishhooks. Don't use yellow handle snips for a cut on a round pipe. You must use either the red or green handle snips depending on the direction of the cut. Don't use cheap snips, Wiss makes good ones. Put a drop of oil on the cutting edge to make it work smoother. If you haven't done this a lot, then use the angle grinder.

 

[WoodyIsGoody]

I would not want to sacrifice a good seal at the stove. I would much rather skip the adapter if Price lets you. If you are forced to use the adapter then I might use a better brand or try and seal the collar with something, probably unsuccessfully.

O.K. I spoke with Price at Selkirk. He informed me the fit is supposed to be a loose fit. His explanation was that since the inside of the stovepipe is a negative pressure area, smoke will not come out. A little air might go in, but not out.

I told him I was confident smoke would not leak out, my concern was with the air that would go in and reduce the available draft. He said if the outer wall is resting on the stovetop, there is no way for much air to go in.

I asked him about using 1/4" plate steel to fabricate a free-floating support collar that would support the outer wall of a regular stove pipe section and that would rest on the top of the firebox (allowing me to connect the stovepipe which fits tightly without the adapter). He said if I wanted to do that, sure, that would be fine, but that the loose fit of the adapter would not matter at all and he said it with a tone that signaled he didn't want to discuss it further.

He also confirmed the reason the outer wall must be supported is for structural support reasons, not airflow reasons (three screws into the stove collar not being sufficient support).

Sensing he didn't want to discuss it further, I thanked him for his feedback and let the call end.

Here's how I see it. The very loose fit at the collar will be under a vacuum, quite a strong vacuum with a hot fire and a low thermostat setting. It will create a an equal vacuum between the two walls of the pipe (assuming that space was airtight). This would be fine assuming the outer wall was airtight at the bottom and the top (where it connects to the chimney adapter). Oh, also every outer wall seam connection on the 12' run to the top. Oh, also the extendable section. But folded pipe seams cause air leaks at every joint and the 66" extendable section is also another major source of air entry because the slip fit is not that tight, there is no gasket and I will be using it neat it's maximum extension of 3" min. overlap of the sliding sections. The top and bottom of the 12' run are not gasketed either. That's a lot of small air leaks.

Wherever there is a leak in the outer wall, it will draw room air into the space between the walls and it will draw the heated air between the walls right up the stack (via the large gap between the inner wall and stove collar). So not only is the insulating effect of the double wall pipe greatly reduced, but the draft available to the stove is reduced. And, all the air that was heated by the inner wall is sucked right up the chimney.

Blaze King has minimum acceptable chimney heights for good stove performance. This height is based upon supplying the stove with adequate draft. I would like to know if the stove manufacturer approves of the use of a double wall stove adapter that is such a loose fit in the stove collar. BKVP?

 

[kennyp2339]

If the makes says that the outer jacket must lay on the stove flat then so be it, that loose connection of the inner wall will seal up with creosote after burning a while and all air infiltration that your worried about will go away.

 

[WoodyIsGoody]

I should add, any air that is sucked into the double wall space from where the ungasketed outer wall rests on the stove top will be sucking heat off the top plate of the stove and stove collar. Most of this heat that would have gone towards heating the house will go right up the chimney.

All of a sudden the double wall pipe, pipe that was supposed to be increasing the efficiency of the system, is sucking heat up the chimney, right from one of the hotter areas of the stove (around the collar).

 

[WoodyIsGoody]

If the makes says that the outer jacket must lay on the stove flat then so be it, that loose connection of the inner wall will seal up with creosote after burning a while and all air infiltration that your worried about will go away.

My experience is that leaks around the stove collar do not plug up due to the high temperatures and because air is always being sucked in. I burn dry wood.

The "loose" connection is a HUGE gap. I would estimate 1/8" all the way around. It's not going to seal up.

 

[kennyp2339]

My experience is that leaks around the stove collar do not plug up due to the high temperatures and because air is always being sucked in. I burn dry wood.

The "loose" connection is a HUGE gap. I would estimate 1/8" all the way around. It's not going to seal up.

Rope gasket?

 

[WoodyIsGoody]

Rope gasket?

I'm not sure rope gasket would hold up to flue collar temperatures.

 

[Highbeam]

That's BS. Price should be ashamed of that answer, Selkirk should be ashamed of that answer, I would return that crap and buy a better product before half a$$ing the installation as Price advised.