2x6 verses 2x9

[sap runner]

I am thinking about changing my rig and would like to know is there anyone out there that knows if a 2x6 arch is the same as a 2x8 or 2x9 as far as the firebox area is concerned.Does the back ramp hit the syrup pan on the bigger ones or does it have a longer firebox.I am thinking of making mine longer and putting my 2x2 first then a new 2x3 and then my flue pan last,becaause of this mod my flue pan is back behind the ramp angle and I am not sure if I would still have a good boil in the back.Thanks ahead of time if anyone has an idea.

[vtsnowedin]

Dropped flue or raised flue would make a big difference on that set up. Dropped flue would be no problem but a raised flue you would need the baffles in the right place to direct the flames up into the flues.

[brookledge]

The fire box would be the same. And if you are looking to add length to the arch(with a raised flue) do it in the middle of the flue pan, that way you do not affect the angles of the fire going up or down. If you have a drop flue you can add the length at the end, just extend the back casting for the smoke stack
However you won't get much added boiling rate by adding another syrup pan.
you would be better off with a 2X6 or 2X7 flue pan and keep your 2X2 syrup pan.
Keith

[PerryW]

I would guess that the stack would also be a larger diameter (and longer) for a 2x8 or a 2x9.

For example, I believe a 3x8 has a 14" X 16' stack and my 3x10 has a 15" x 20' stack.

[3rdgen.maple]

I agree totaly I think you would be alot better of adding a 6 foot flue pan to it than another flat pan. That way you could keep the ramp as is and just add the length. 2 more feet of flues would give you a much greater surface area than a 2x3 flat would. Seems like it would be alot of work for little return without the extra flue length.

[sap runner]

Thanks for the replys and with that being said I think the best fix is the flue pan.Now can I extend the back of the arch,basicly move the stack back and add another 2x4 flue pan behind the original setup making it a 2x10.Seems like it is easier to find a 2x4 pan verses a 2x8 flue pan.I think I would have have a few ramps to get heat up inside flues,with that setup I would be able to have one float box to maintain both flue pans.Do they make a 2x8 flue pan?Seems like the extra work changing over the arch would be well worth it verses a different evaporator all together.I rebuilt it last fall,all new brick grates,air to the back of the fire box and a brass/glass wood stove door.It can be very relaxing watching that fire burn,thats the reason I don't want to give up the whole set up,not only that it's much fun building than anything else.Im sure next year I will try to add again or re-invent the wheel:lol:

[RileySugarbush]

I'm thinking along the same lines. I added a probe type stack thermometer this season and observed up to 1750°F 2 feet up the stack. I'd rather expose sap to those temps than just a stack. I already have a relatively large sap pan at 24"x33".

Adding another drop flue sap pan or replacing my 3' with a 5' or 6' seems like the way to go. With forced draft and air tight arch, I think the need for a large stack is gone.

[vtsnowedin]

I'm thinking that a two foot wide rig needs the same size stack no matter how long it is. Your just giving the hot gasses a longer time and surface area to transfer their heat to the sap in a longer setup. Air in equals air out so the stack size should come from the width of the arch not the length. That being said I have seen three foot wide rigs with everything from ten inch to twenty-four inch stack. Once you go past the minimum it hurts nothing to be bigger then necessary you just slow down the velocity of the smoke. I suppose some one has tested this out and published their results but I would be surprised if they concluded that any two foot wide rig needed more then an eight inch stack regardless of the length of the arch.

[brookledge]

That is my feeling. The size of the fire box governs the diameter of the stack. The length of the arch governs the length of the stack and should be a minumum of 2 times the length of the arch
Keith

[dgp219]

If you are modifying your arch what about putting a drop flue between the syrup and raised flue pan, or even a WF Mason tube flue pan, check out his web site they look coolhttp://mapletrader.com/community/images/smilies/cool.gif!