Rear Pan Not Boiling Well

[Maple Hunter]

I recently upgraded to a "new" evaporator, which I thought was a 2x6. However, turns out it's 20" x 5'. The whole thing apprears homemade, but pretty well done, especially the pans. I fired it up for the first time today and was rather disapointed to find the back pan rarely went to a boil. I built up the rear section with fire brick and would say it's probably 1 1/2 - 2" from the flues. Lot more smoke than usual, so I'm guessing there's a draft issue, but not sure what else might be wrong? Front pan boiled fine, but of course the fire is right there. I'll try to post some pics of it later tonight. Would definitely appreciate any thoughts!

[rcbulldog]

Have you got a lot of soot buildup on and around the flues? I brush my drop flues out before every boil and it goes nuts.

[vtwoody]

Should be a gentle roar like a freight train or the sound of an airplane while riding inside....the smoke issue might mean it needs more air...assuming you are not using a blower, how wide is the spacing of your grates? getting enough air through? soot/creosote on pans/flues insulates from the heat - clean them off down to shiny metal for better heat transfer. Are you using dry, split-small (wrist size) wood? is your chimney at least twice as tall as length of rig (5' X2' = 10')? All common places to look at for getting better boil. I know all of these issue from experience.. ;)

good luck!

[maple man-iac]

One, not enough air for whatever reason. Two, the bricks should be up to your flue drop. Three, possibly not enough draft from your stack, too small of diameter and or not tall enough.

[Maple Hunter]

From the back pan I bricked level all the way to the stack opening, so maybe that's one of my problems with draft. Should I drop it back down a little before? Stack is roughly 6'. Hoping to get this thing right before the season ends or I run out of storage. Thanks for the ideas so far, I'll certainly be trying some things tomorrow. Oh, one more thing. The stack was never too hot to touch, no matter how hot the fire.

[nymapleguy607]

Front pan boiling with little boil in the flue pan means there is not enough draft. Generally you bricks should be within an inch of the flues. If this is a raised flue you will need to have an area before the stack collar to let the smoke go back down into the arch. It sounds like this is a drop flue so you shouldn't have to worry about the step down. I would add another section of stack so its closer to 10ft that should help alot.

[Flat Lander Sugaring]

AUF, more stack and like said before with in 1/2 to bottom of flues

[Maple Hunter]

So here's a bottom pic of the rear pan. Prior it was fairly clean. The majority of it is covered in a thin layer of what I assume is creosote, which appears to have mixed with moisture creating what looks like black powder coat. Hopefully this won't be too hard to clean. I opened up the stack area, so hopefully I can try that and see what happens.

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