"Real Evaporator" rookie seeks advice on stting up his arch and flue pan gadgets

My questions are many, but my brain is small. I will ask only what I can handle. A few questions at a time.

1. My garage is set up for a wood stove with a 6" flue chimney. My new (used) Small Brothers evaporator 2 X 6 is set up for an 8". can I reduce it at the ceiling? Will a longer stove pipe compensate?

2. The former owner used LP in it. I will be burning wood. He had the whole flat back of the arch filled with a combination of fire brick and just plane old 1880's red brick. Can I do the same? Other suggestions.

3. I see some manufacturers tell you to line the wood box/arch with high temp cement board and then brick. Should I do this?

Many more to follow if you can share your wisdom, it would be much appreciated.

Made about 60 gallons of syrup on a primitive flat pan/oil tank set up last year and years prior. Work schedule says get alot more efficient and FAST!

OK to start off, how did u make 60 gallons of syrup if your a rookie ? thats alot of syrup to make ?,
You can always just get a adapter for the pipeing as long as u have a good draft u will be just fine?
Adding any aditonal fire brick fire board blower is going to increase your boiling rate, i dont know how well old red bricks will work tho .
i would be glad to help answer anymore questions if u have them i just started last year but i have worked at a sugar house for a while .

To answer a few of your questions, 1. I am not really sure about the stove pipe, but I would guess it would be OK, especially if you add more length to it, and have a good draft or forced air.
2. You could use the same method that he used, it would work fine, BUT you wouldn't have the best insulation and in the long run, the red brick adds a lot of extra weight onto the arch, possibly aging it a little faster. To cut down on weight, you can use several things under the traditional firebricks, I put ash in the back of arch, then cement board and then firebricks; the ash cuts down on the weight, while still adding good insulation and takes up the space to allow the least amount of room between the firebricks and my flues (less room between is better, forces more of the heat into the pans for better efficiency and evaporation rate.
3. Once again, the more insulation the better, it will increase your evaporation rate, cutting down on your boiling time. In my firebox, I used ceramic fiber blanket first, then the cement board (arch board) and then I put the thinner firebricks (using cement to hold them in place), with this combination you can put your hand on the side of my arch without getting burnt. Not all of this is needed, but in the long run it does save time and also wood. I would also recommend adding forced air if you don't already have it, at least under-fire, you will get a better boil in your front pans and all the way to the back of the flue pan.

Good luck.

#1 6" sounds too small. If a test only costs you the price of a 6" to 8" adapter (you might try galvanized first for the test) then I would test it with a water boil. If you think you will add a fan, then I would go to 8 or 10 and skip the test...

I've read about fires starting from where stacks meet wood. Working out of your garage, you should be extra careful. Give yourself plenty of clearance and insulation, especially if you stick with the smaller stack (I assume it would get hotter than wider stacks).

#2 Assuming there is no insulation under the back brick and that it is all cemented in place, it might be easiest to just lay ceramic blanket down in the back (don't breathe this stuff in!) if you can afford 2" under the pans.

#3 My firebox is lined with ceramic blanket and then firebrick. The walls are a little bit wobbly in a section where the cement cracked, so I'd recommend the board instead.

60 Gallons on a flat pan? You had no sleep last March...

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Originally Posted by hikewithmike

My questions are many, but my brain is small. I will ask only what I can handle. A few questions at a time.

1. My garage is set up for a wood stove with a 6" flue chimney. My new (used) Small Brothers evaporator 2 X 6 is set up for an 8". can I reduce it at the ceiling? Will a longer stove pipe compensate?

2. The former owner used LP in it. I will be burning wood. He had the whole flat back of the arch filled with a combination of fire brick and just plane old 1880's red brick. Can I do the same? Other suggestions.

3. I see some manufacturers tell you to line the wood box/arch with high temp cement board and then brick. Should I do this?

Many more to follow if you can share your wisdom, it would be much appreciated.

Made about 60 gallons of syrup on a primitive flat pan/oil tank set up last year and years prior. Work schedule says get alot more efficient and FAST!

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First. Is your 6 inch flue up to codes??? Did you have it inspected for cracks? Given what I have been reading here we are talking serious flue temps. I have never been a fan of reducers and reducing 2 inches seems a lot. Might end up looking like a blowtorch on top of the garage at night. :lol:

Thanks for the quick and helpful replies. We boiled 19 times last year to produce 60 gallons and used all of our (and our neighbor's) firewood supply + 3 more trailer loads. Plus had to fight to collect sap (bags) before and after 10+" of snowfall at least 3 times last season and the snow never went away all season. I became an expert at getting my 4 wheeler unstuck. Attachment 9020 Clearly, maple syrup is an addictive substance, or I would not be back. This is my fifth season, but we have always been a very primitive and overzealous operation.

4. If not using a temperature regulated valve to draw off the syrup pan (I'm broke just buying the used evaporator), what are your best recommendations for monitoring and controlling at the draw off. I've never even seen one of these things in action, so I am clueless. How much monitoring is involved? How difficult is it to tweak it just right with the unstable heat of a wood fire?

With a flat pan, I just filled it, loaded the fire box, and walked away for a couple hours if I needed to, and accepted the lower evaporation rate. What to I do in the same scenario with this contraption.

The stovepipe is up to code.

The rule for stove pipe is you can always bigger, but never smaller. With evaporator temps usually averaging 500-1000 degrees in order to get a good boil going, I would really think hard about using that little 6" pipe. Or you just won't get the draft you need to produce for you too. I have a 2x6 with a 9" pipe and which it was bigger sometimes, especially after I have air added to it now. I actually caught my roof on fire the first year I started because I only used a typical ceiling roof jack.. I was so glad I had a water hose nearby. Be careful man....

60 gallons on a flat pan? I am impressed.... :)

To answer 4. I hope you have a hydrometer and a testing cup, along with a good thermometer; I have a 2x8, with no automatic draw off and I manage, you just keep to keep testing the syrup at your draw off point until it is close to being done; you don't want to push it too much though, because once it turns to syrup, it turns fast and you're likely to burn your pans. Once you do it for a few boils you'll get the hang of it and know what signs to look for when its getting close, trial and error; just hope for very few errors!

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Originally Posted by hikewithmike

With a flat pan, I just filled it, loaded the fire box, and walked away for a couple hours if I needed to, and accepted the lower evaporation rate. What to I do in the same scenario with this contraption.

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You dont load and walk away... unless you like buying new pans. I fuel my 2x6 every 5 min.

Never ever walk away from an evaporator. Its amazing how much can go wrong in the blink of an eye! We always run with two of us, one at the evaporator and the other watching every thing else, and standing in for lifes necessary stops!

your not primitive any more. This is much more a production process, This evaporator will need pretty much constant attention, either getting wood, firing the evaporator, checking or rechecking the sap levels, watching the syrup temp near the draw off, checking the density of syrup. Repeat the process several hundred times per season. You will be busier. Best to have several people watching some of the first boils till you have made several gallons of syrup off the rig. Good news you have made a lot of syrup and you have been through the basics of making syrup. This is a different tool. You will like it!
I love the four wheeler and the sap tank!
Regards,
Chris

Just with wood stoves... smaller pipe will give more draft. It's physics

6" is just fine. Reduce it at the Evap not at the ceiling.

I would worry about the steam getting out of the garage more. Are you running a vent of some sort?

Quote from WoodHeat.org

Chimney Size Should Match the Appliance

Chimneys that are over-sized for the appliance they serve are common, partly because people used to think that bigger is better. Now it is clear that bigger is not better when it comes to chimney sizing. A given volume of flue gas flows faster and has less time to lose heat in a small chimney flue than in a large one. In planning wood heating systems, experienced installers will sometimes choose a chimney that has a smaller inside diameter than the appliance flue collar.