Dumb Question of the Day

[SeanD]

I'm truly embarrassed that I have to ask this:

Which end is up on a smoke stack - the small end or the large end?

Up til now, I've done small end up so the smoke, like water is traveling into a female end so nothing gets out inside the shack. The trouble is that condensate and rain can run down the inside of the stack, mix with soot and then run onto the outside of the stack trashing it.

I've had black pipe before and it looks awful after one season, but now that I have some stainless, I definitely don't want to mess it up.

Sean

[ADKMAPLE]

I beleive the small if it is a nesting pipe, however everything else should pretty much be the same diameter and just piece together in sections.

[ejmaple]

small end up. if you do already have it set up that way you shouldn't have water running into it like you would if the large end was up.

[Ausable]

I'm truly embarrassed that I have to ask this:

Which end is up on a smoke stack - the small end or the large end?

Up til now, I've done small end up so the smoke, like water is traveling into a female end so nothing gets out inside the shack. The trouble is that condensate and rain can run down the inside of the stack, mix with soot and then run onto the outside of the stack trashing it.

I've had black pipe before and it looks awful after one season, but now that I have some stainless, I definitely don't want to mess it up.

Sean

Sean -- No question is dumb -- just some have more humor than others. Ha - Looks like you are getting answered both ways - now I too am confused. It has always been my experience with single wall black pipe - that the crimped or small end goes down into the stove collar. That of course is for natural air flow wood stoves and sap evaporators. But - now - this has got me to thinking (always dangerous) ---maybe on forced draft evaporators - it might work better with the large end down to keep some of the smoke out of the sugarshack and out the stack. So -- both answers could be right - depending on what you have -- Really -- it is a great question --- Mike

[ToadHill]

Small end = crimped end. Small end up + big end down = no smoke in sugarhouse + no water running down inside the evaporator.

Hope this helps.

[markct]

i found that i got some ash leaking out when it was installed small end down (like a woodstove to keep creosote from leaking out) on my forced draft arch, so i put it pointing up so the flow of smoke is not getting pushed out joints, and no longer does rain water get in the stack joints either. creosote realy isnt an issue with an evaporator, i know on my woodstove tho it sure does run down the inside of the pipe and find any leak it can!

[Brokermike]

I would think you'd want the small end down, keeping any run off inside the pipe

[ToadHill]

As Markct said there really isn't any creosote in an evaporator stack. So there really isn't anything that will run down the inside of the stack if you put the small end up. If you put the small end down water will run down the outside of the stack and into the joints and get inside the stack and run down into the back of the evaporator. There it will mix with the ash and the end result will be the formation of a mix that will prematurely rot out the back of your arch.

[SeanD]

With my black pipe, small end up, I got corrosion and rust all down the outside of the stack. A lot of it is in the shape of rivulets from liquid coming out of the seam and running down the outside of the stack. Maybe it wasn't soot, but it's definitely rusted and corroded.

Sean

[ToadHill]

Black pipe and galvanized will rust regardless of what you do. The heat destroys the galvanizing and it will rust 10 times faster after that. Stainless steel can get hot and will not rust. I'm on my 3rd evaporator with a SS stack and none of them has rusted. Some water will run down the outside of the stack if you don't do something to prevent it. If you insall the pipe with the small end up you can prevent any damage by installing a roof jack with a rain collar and then sealing it with some high temp silicone or furnace cement (out of my area of expertise on that one). That said, if your stack is small you would be best to take it down at the end of the season. That way you won't get any water running down the outside onto the back of your arch. I have dealt with a lot of arches that had the back end rotted out and the rest of the arch was fine. Most producers that haven't experienced this don't realize it until the damage is done.

[ejmaple]

i would rather corrosion out side on the stack than inside my arch.

[SeanD]

Well I have a couple of sections of stainless that will be up top so they should be good. The lower 12' are galvanized, though. I hope they last longer than the black pipe. I know black pipe has the shortest life span, but this is what it looked like after ONE season.

Sean

[markct]

i would put the stainless at the bottom of the stack where it will get the most heat, thats usualy where they fail first

[3rdgen.maple]

I would buy all stainless;) More upfront less down the road.

[Haynes Forest Products]

Lets start from the TOP shall we. If you start with the rain collar then its all the crimps at the top of the pipes. If you start at the bottom with the Starting flue pipe that might also be called the base stack / transition section then its crimps up. All base stacks that I have ever seen come with the crimps up. I have never been asked it I wanted a base stack without crimps. I believe all applications would include some kind of rain cap and I have never seen a rain cap that was crimped. If you think of the joints like you would shingles then it only makes sense that the crimps are at the top of the section so the next section of pipe would overlap the lower pipe making a water tight joint. Its a complete sytem starting at the base to the rain cap. leave off the cap and you cause unintended conesquences.

[Ausable]

Well SeanD -- Turns out that your question was really not Dumb at all - In fact - at this point - You might already wish you hadn't asked - as everyone seems sure of their answer - just can't agree. Good thing stove pipe only has two ends or the answers would be endless. I guess the right answer might be - do what works for you. Black single wall dosen't stay nice for long when exposed to nature and during the boiling season most of us run with no storm cap of any kind - do to the rip-roaring fires we have going. You got us all to thinking though and thats a good thing - sorry to leave you confused. - Mike

[maple flats]

Mine are all crimp up. I have a cap on all the time, right now it is a coolie type cap but I bought a flip cap that will be installed next summer. These keep water out quite effectively. Some gets in but very little.

[SeanD]

Thanks for all the input. I'll just keep it crimps up the way I've had it and hope the storm collar and cap keep more of the moisture out.

Thanks,
Sean

[kiegscustoms]

I will throw another thought in there for everyone. I always run flue (smoke) pipe crimp up so the water / condensation will run out the sides of the pipe. It is a lot easier to replace a section of pipe than the bottom of your evaporator, or stove. On the other hand with steam pipe I would run that crimp down so all the condensation runs back into your condensate pan. Last year we ran our steam pipe crimp up and the excessive amounts of condensation coming out the sides of the pipe made a big wet mess inside the sugarhouse and all over the top of the steam hood. This only works if you have a preheater with a condensate pan or a pan under the steam thimble as dave described in a different thread. That way all the moisture ends up in your condensate catch basin or tank, and not on the floor or your head or other places you don't want it.