Stack Size

[Amber Gold]

I have an old 2x6 Grimm and was wondering what stack size to use. I found a previous thread with sizes ranging from 6-8" and I thought someone had mentioned a 10". I'll have about 20' of stack, including the base stack, and conditions can get fairly windy. If it matters, the wind will be coming from the west, which is the direction of the front of the arch and the garage door.

Also, why are the flap style stack covers used versus the style that I have on my metalbestos chimney pipe for my wood stove?

Thanks

[softmaple]

my guess is less restriction on flue gas flow which is better draft

[Dill]

Robbie runs a 10 incher on his 2x6. I have a 6inch stack on mine currently, I think I'll go 8 next year, but I have to seal it up better anyway.
I would guess the flap style would be since you don't use it 11 months out of the year, you can seal it up tight and keep more water out of it. Where as you need you woodstove more often.

[Amber Gold]

Is it bad to get too much draft? I'm just wondering if you get too much draft if most of the heat goes up the stack. Obviously if you don't get enough the fire won't get hot enough.

[WESTVIRGINIAMAPLER]

About all 2x6's now come with 10" stack.

[RileySugarbush]

Brandon,

If you bought a 2x6 with a blower, would you still get a 10" stack on it? Seems to me that is too much and with forced draft, a little less stack draft may be a good thing. My 2x6 does 35 gph with a 8" stack and a 210cfm blower.

[WESTVIRGINIAMAPLER]

I would think 8" would be plenty on a 2x6 with forced air. I have 10" on my 2x8 inferno arch and I still push 1600+ stack temps.

[tuckermtn]

yes- 10" is what came with my 2 x 6. have you built your suagarhouse yet? if for some chance you have a 7 or 8 pitch roof (can't remeber which) , I have a good roof jack free for the taking...

I've used the flip over stainless covers...first one I used a piece of nylon cord to open and close...didn't last long...

[Amber Gold]

I don't intend to put forced draft on my 2x6, so it sounds like I'll need a 10" stack.

I haven't built my shack yet, and probably won't be able to until next summer. I'm drafting up the plans for it now and it's looking like it'll be a 30'x20' building with 16'x20' garage and 14'x20' sugar shack. I'm also figuring a 10'x20' wood shed off the side to store my house and sugaring wood. I was planning on posting my plans when they're completed to get feedback on the design/layout.

I am planning for an 8 pitch roof though and would be happy to have the roof jack. Thanks a lot. I'll send you a PM with my contact information.

I noticed that you can get 3' or 6' tall base stacks. Is one better than the other?

Thanks

[RileySugarbush]

I really recommend including forced combustion air. It's easy, relatively cheap if you have electrical power available,and really makes a 2x6 crank. I just got up from a great day of boiling at over 35 gph for 6 hours and I bet I didn't leave more than a cup of ash.

[danno]

I agree with John. Re-think that forced air thing - you won't be disappointed. Probably the least expensive improvement you can make to improve evaporation.

I tried partially blocking off the stack to see if I could keep the heat under the pans. I get huge draw on my 14" x 20' stack. Did not work - dampening stack just reduced the temps and the boil.

[WESTVIRGINIAMAPLER]

Ditto to what Danno said.

My arch is identical to an inferno arch except it doesn't have a floor and the may not have had a floor in it when I bought it several years ago. After one year without an airtight setup, I changed it over. I went from averaging 35 gph including startup and shutdown regardless of how I fired it to 60 to 65 this year which is 72 to 85 percent gain in evaporation. I also added a preheater, and it seems to contributed about 10% to that number the best I can calculate.

[Russell Lampron]

I have an 8" stack on my 2x6 and don't see the need for a bigger one. I don't have forced draft either. I closed the bottom of my arch off with fire brick and just used the draft door to control it but removed 2 bricks in front and one brick in the rear and now it really cranks. I get a good boil all of the way to the back of the flue pan and still have good heat under my front pan. My stack is 17' tall and I am planning to add another 4' section.

In the future I am planning to have an intensofire type arch built to replace mine so that I can add more taps. At that time I will add another membrane to my RO machine so I can handle the extra sap.

[Amber Gold]

I'd probably have about 20' of stack.

That's an amazing increase in evaporation rate. I have the older style arch with the double doors and no floor on the fire box. Can I convert it to a forced draft system, and if so, how would I do it? If I did go forced draft would I still want a 10" stack. I thought I had read with a forced draft system that you drop the stack size down one. Not sure though.

[danno]

I've made my past and current arch "relatively" air tight for forced air. Glued wood stove door gasket to all doors. When I'm running forced air, I get no spark or smoke in the sugarhouse. I've noticed bigger the stack, the better the draft. The better the draft, the less likely smoke or spark will filter through the doors - it's all getting sucked up the stack.

Also insulated my doors so I don't have to worry about cracking them due to the high temps cause by forced air. The steel inside my insulation glows red but the outside of the doors stay much cooler.

[Justin Turco]

We are using an 11 inch stack on our 2X6 and we like it. (leader said we would.) We also have a blower that we put on this year which is a great improvement. We made ours to look exactly like the woodsaver in leaders' catalog. I don't believe we are "saving" wood but it gets the back pan boiling as if we were burning the best wood we ever had. I have a stainless 36" inch tall basestack that will fit your rig for sale for $100., $185 new. (it's for 11" pipe) (I think lengths of stainless pipe sell for $80.) Wouldn't fit mine because my cast iron base flange is not a grimm...apparently. The basestack is in very nice shape.

I ran a 10" before I came across this 11" stack. 10" is perfect for a 2X6. My final word...Make a blower... Oh yeah..and use stainless tinwork when you restore your 2x6 if you can..it will look so nice!

[Brent]

Josh
the Phaneuf came with 12 ' of 10" stack. I was not getting very hot temps and I was not clearing the roof safely for sparks, so I added 4' more. Temps went up 150 to 200 degrees.

Next year I will likely go with forced draft.

The Chinese hat caps keep 80% of the rain out.
The rope operated closers will keep 100% out.
Rain in the stack means rain in the evap = RUST

But you need to tie them off both when open and closed. I had mine blow open a couple of times. The other issue is keeping heat in the sugar shack. I went up on the roof one night a few hours after a boil ... I think I could have cooked a hot dog in any of the 3 stacks. If you need to keep the shack from freezing at night the heat loss through the open stacks is HUGE. I've ordered rope closers for both the steam stacks now.

[Amber Gold]

Justin, do you have pictures of your setup. I'm not really sure what you're talking about not having seen a forced air setup before. I'll get back to you about the base stack. Do they make reducers for 11"-10" pipe?

What is used to insulate the doors with?

I got some sheet metal prices at onlinemetals.com and was originally planning on using 18 ga sheet, but it is expensive. It was going to be about $690 for stainless or $288 for galvinized. If I go to 22 ga. the cost comes down to $574 for stainless and $173 for galvinized. The cost for 20 ga. was the same as 18 ga. Although stainless would be nice, it's hard to justify that much of a cost difference. I haven't checked with local suppliers, but can't imagine they'd be that much cheaper. I've checked with local scrap yards and I don't think I'd find two flat pieces that are 28"x80" Is there any reason why I shouldn't use 22 ga.?

If I'm running a forced draft system is it typical to have stack temps of 1200-1400 degrees, and if so, would I need a stainless stack?

Thanks

Josh

[RileySugarbush]

Josh,

If you can find a local weld shop, they will probably have some sheet metal in stock and it will be far cheaper than online purchases due to shipping costs. I have a semi airtight (leaky cast iron door and rarely a bit of a leak around the pan gasket if things get bumped). I used 1.25 x .125 angle for a frame, 16 gage steel sheared to size by the local guy, and a strip of 1x.125 as a bolting strip on the edges. To attach the panels, I laid it down so they were horizontal, put down a bead of high temp sealant and put on the sheet and bolting strip. Then I just fastened it with self drilling/tapping sheet metal screws. Very fast to do with a drill and hex driver!

With my 8" stack and a 210 cfm blower I get 800 to 900F at the stack (with a magnetic thermometer, so it is likely a bit higher) and 35 to 40 gph on this 2x6, even with my short sap pan. I get enough draw from the stack that the blower doesn't shoot flames wildly out the door seams.

I insulated the front and door with 1" ceramic blanket wedged tight on the edges and held in with stainless fender washers and screws. I just tapped 10-24 threads in the cast door and front and screwed the blanket on from the inside. Even though this is in the firebox, the wood doesn't usually bother it since you are chucking it in and away from the front. It has held up fine after 2 seasons now.

[SeanD]

I opted for the arch board to insulate my sheet metal front and door. It worked great up until the high temp. gasket seal and gave out and it fell right off the sheet metal.

I was so bummed out. It was working so well that I could handle the latch bare handed. Once it fell into the firebox in the third or fourth boil I just watched the front warp before my eyes. There's something about the sheet metal that just wouldn't hold the sealant.

I wish I had tried screws, but I was afraid the screw heads and washers couldn't take the heat. It's good to hear that doesn't happen. John, how far apart did you space the screws?

One good thing to come out of it was that in my effort to keep the heat away from the door, I threw the wood to the back of the firebox and ended up getting a better boil in my back pan without losing too much in the front.

Do you think my front could recover from the warping? I'm going to try hammering it out flat again, but I don't know anything about the properties of metal. Now that it's been heated, warped, and cooled a few times is it more likely to warp in the future?

The door surprisingly stayed pretty flat, but I'm not sure how to hold the rope gasket on. That fell off in the seventh boil!

Here's a before picture. I don't think I can bring myself to take an after picture.

Sean

[WESTVIRGINIAMAPLER]

Stainless bolts and nuts should work good. They might have to be replaced after a couple of years, but should last at least 1 or 2 years if not much longer.

[RileySugarbush]

I tapped the arch front and screwed in the #10 stainless screws and fender washers through the blanket. I think they are spaced about 6", with only 4 going through my cast iron arch door.