3 x 10 owners

[bees1st]

I've got a raised flue 3 x 10 with a 7 ft. flue pan . my stack seems overly laqrge at 15". just wondered what other rigs simular to this out there have?
every thing I see says I should be getting 70 - 80 gals / hour.I'm firing it hard with good dry wood, split real fine and am getting only around 50 gal/hr with a preheater!!! used to do better with my 3 x 8.banging my head on the wall here.

[Farmboy]

Mabey not enough stack. My 2.5X8 has a 14" stack. Im getting 55-60 gph. How tall is your stack it should be atleast 20'. It also depends on the brand for stack size.

[bees1st]

yup, I've got 20 feet of stack

[bobbyjake]

when we had a 3x10 and preheater and forced draft (just a blower stuck in the back, nothing fancy) we could crowd 100 gph. 20 is barely enough, a 10' evap is actually 11' long, so 22 feet of stack or more can't hurt. How much daylight do you have under the flues, it should be more than an 1" and 1/2" would be fine too. What is your stack temp? Are you throwing the heat up the stack, or getting good use of it.

You are right, it is really dogging at 50gph.

Good Luck

[Fred Henderson]

when we had a 3x10 and preheater and forced draft (just a blower stuck in the back, nothing fancy) we could crowd 100 gpm. 20 is barely enough, a 10' evap is actually 11' long, so 22 feet of stack or more can't hurt. How much daylight do you have under the flues, it should be more than an 1" and 1/2" would be fine too. What is your stack temp? Are you throwing the heat up the stack, or getting good use of it.

You are right, it is really dogging at 50 gph.

Good Luck

I have a 3' x 8" with a hood and a parallel heater doing 90 gph.

[Southtowns27]

I have a 2.5x8 with a 14" stack 18' tall, crappy preheater, and forced draft. We had it up to 93 GPH the other night, usually runs about 75-80. What's your stack temp? How deep are you running your pans?

[mapletbdf]

I have a 3/10 air grates with blower no preheater , 14 in stack 20 ft tall . Try placing some fire brick in the back before the stack to slow and force the heat in the flues . Fire with a stack temp. 800 / 900 I am getting about 125 130 of mine with a high eff pan

[sfsshadow]

if the front of the syrup pan doest boil, you have to much stack. if you have smoke when you open th doors, you dont have enough stack. you should have 2 in between the bottom of your flue pan and the top of the bricks in frontof the flue pan

[bees1st]

thanks all ,guess I'll have to check my stack temp. no smoke when I open the doors, front of the syrup pan is boiling but not real hard.I have the pans sitting on 1/2" of gasket compressed down to 1/4" or so.I think I should get a brush and clean the flues, don't know when that was done last.Guy I bought the rig from claimed he could do 80,course I tore it down to move it then rebricked it. used arch board too.

[Fred Henderson]

I know we have all said what our own rigs will do but I don't know if it will help you. Definitely get a stack thermometer. If the stack is SS you will need to wire it to it. Brushing the flues down before each firing will help. I know in my own case it take about 4 firings to get the stack to 500 degrees. I have 2" of ceramic wool and then bricks.Once I see the bricks in the fire box red hot I am in for smooth sailing.Also because of where my shack is located I use 18 ft of stack.

[WESTVIRGINIAMAPLER]

I brush my flues before every boil and it definitely makes a big difference. If you flues haven't been brushed in a long time, it is hard to tell how much buildup is on them insulating them from the fire. May take 2 or 3 boils and brushings to get off all the buildup. With good wood and firing it right, you should be able to do 80 to 100 gph.

[bees1st]

brushed my flues today before the boil, got her up to 70 gal/ hr.didn't know it would make that much difference!!.Still feel my spacing is too much by the exit at the back end.may lay some 1/2 bricks in there and see if that helps.

[WESTVIRGINIAMAPLER]

May help again brushing them the next boil because there is no way you got off all of the buildup in one brushing. I try to brush mine every boil even if last one was a short boil. Definitely makes a difference.

[mapletbdf]

When we first got are rig are rate was down, by my brother equaled the draft coming off the rear slope to the square inch of the grates . Are boil rate was low by adding some fire bricks in the back we picked up about 30 gal an hour. It you have ss stack get a stack therm. with a stem and drill you stack good luck

[PerryW]

I get 90 - 100 GPH out of my 3x10 with no preheater. 15" stack - 20 feet long. For the record, I never clean the bottom of the pans till the end of the season.

[bees1st]

Just an update -- I laid some 1/2 fire brick in the back to restrict to air a little more, bumped it up to just under 100/ hour . what a relief