Fuel tank arch

[Lilshot]

Small time maple syrup addict here. Used a 10 gallon pot the last couple of years. FIL had a 275 fuel tank rusting away beside his garage. Decided to use it to make an evaporator arch out of it. Became a member here and went through old posts getting ideas. Sounded like good idea to recycle a used fuel tank but the curves present quite the challenge. Barrel stove kit for the door and stack adapter. 2" ceramic roll insulation and 1/2" cement board and topped with fire brick for the combustion chamber. Ceramic blanket across the arch to the flue. I have 6" below the grate and 17" above the grate in the fire box. Fire box is 20" deep. Planning to burn slabs from the neighbors saw mill. Was going to use buffet pans but decided to get 2x4 batch pan from smokey lake. Was looking for suggestions or reassurance on my build. Hope test fire this rig tomorrow.

Collected 35 gallons of sap today and should have that much tomorrow. 5/16 taps in bags pvc holders. Mostly reds, some sugars,and a few silvers for trees. Dragging buckets through the wood lot for collection. Kicks my a$$.

I hope to use this same rig for evaporating sorghum juice as well. Anyone using their maple sugaring equipment for sorghum as well?

PS. How in the world do you get the 6" stove pipe into the barrel stove kit adapter?

Going to try to post pics of the arch. 171491714817150

[Cjadamec]

Nice job on the arch. I went the duct pipe route for the stack. I know it won't last more than a few seasons but both pieces I needed were only 14bucks. You may want to consider going to an 8 inch stack over the 6 inch.

[West Grove Maple]

Just boiled around 50 gallons down today on my fuel tank arch. I have a 2x4 divided pan. I also just picked up a sorghum mill a couple months ago and will be using mine for sorghum also.

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[barnbc76]

I had the same problem getting it to fit, I believe we cut a couple relief cuts in it to let it bend a little to fit...

[barnbc76]

What's with the angle of the brick in the fire box? I would try and make it as wide as the tank will let you. Looks good, how long did it take to boil?

[maple flats]

Most duct pipe is only 28 ga, watch it close, it may not even last 1 season.
Nice looking arch with the SS pans set in. Have you ever considered making some sets of tubes to maintain sap levels? There used to be a system used in the "old" days where a copper tube extended down in one section and crossed up and over into the next. Then on the top most had a way to pull the air out. If the tube remained full of sap the level stayed the same in both sections. You do need to keep an eye on that method and you want a way to pull more air out as needed because a hard boil can disrupt the action as a bubble enters the tube. A little valve with a suction device will do the trick.

[Cjadamec]

Making and equalizer set-up with tubing had crossed my mind but it's one of those finer details I still need to get some time to tackle. At the moment it was a victory just to get the main part completed. Not a moment too soon as I've already put about 100gallons of sap thru it. 3/16th tubing works every bit as well as its hyped up to.

[Lilshot]

I had collected 37 gallons of sap before the cold shut the trees down. Got started boiling yesterday morning and had a boil in just under an hour. Took a bit to get the hang of how small to split the wood and how often to load the fire box. I was able to keep a rolling boil for the length of the pan, except we're the cooler sap was trickling in.

I didn't think that i was getting enough draft and put a small fan blowing into the ash box door. This made a big difference. Very hard boil throughout the pan. It also made the wood leave very little ashes and no smoke coming from the stack. Just as I really figured out how to make it hum, I was down to 5 gallon of sap and needed to start thinking about shutting things down.

Overall I was pleased with how it ran but already see how to make improvements. I currently have 6' of 6" pipe for the stack do you think that adding another 4 or 6 feet would make much difference in the draft? Or would the best bet be to add a blower?

Also I did not insulate the curved portion of the fuel oil tank that the stack is attached to, and was wondering if there was any use to make a shroud around this portion to have a blower pull hot air and put it back into the fire box. Just trying to make the most of the wood that gets burnt. Also would putting the blower entering the fire box from the back cause any issues? What cfm blower would be appropriate size?

Anyways I am probably having more fun than I should with this and looking forward to the next run of sap... This coming weekend 3 days well above freezing. Going to tap a few more trees and try to get 100 gallon for the next boil.

[Lilshot]

Cjadamec 8" stack maybe in my future. Just figured the 6" cast collar came with the barrel stove kit and made it convenient.

West grove maple- I'll be looking forward to get your take on the sorghum process. Trying ourselves for the first time this year. We are planting Rox Orange what are you going to plant?

Barnbc76- that's exactly what I ended up doing with the pipe. Not sure of the angle on the sides of the fire box but the door is only 10" x10" so it works out ok. The grate is 10" wide and tapered out to 23" at pan level. Fire box is 18" high.

I ended up with just over 3 quarts of syrup from this first boil.

Thx all for the feedback and I'm sure I'll have more questions along the way.

[barnbc76]

Sounds like your doing great that should keep you busy... it does take a few boils till you get it most efficient defenately have that blower on and a 12ft stack would be good. Always have that extra 5gal bucket with sap just in case. I like to run my pan with about 1.5" to 1"of sap to achieve best boiling rates. How heavy is your pan when you take it off, that's gotta suck with a 2x4 with just one person batch boil. My 2x3 is bad enough.

[Lilshot]

I didn't pull the pan with sweet sap..as last 5 gallons of sap was dribbling into the pan from the pre heater i just eased up and the wood and air until only front half of pan boiled. Kept low steady fire until there was 3\4 of an inch left in the pan. I was afraid to go any lower. Then pulled the few hot coals from the ash drawer and left stove door open for 30 minuets to cool the fire brick. Then open valve and drain to stock pot to boil down over propane. When it is down to 3 gallons filter into 4 gallon pot to finish inside on stove. Boil till it's syrup and then cold crash it in half gallon jars in the fridge.
Next day, Pour off the good clear syrup till the funk on the bottom starts to come out. Then heat to 185 and into sanitized jars.

We have never had much luck filtering out the fines. Cold crashing the hot syrup really clears it up and makes it easy to decant. Saving the slops from all runs to combine at the end of the season. It ends up in bbq sauce when tomatoes and peppers are ready in the fall.

[Lilshot]

Just sent to check to see if they all sealed and they did. Thought it was time for a family portrait. Batch 2018-02.1725917260

[Cjadamec]

Ducting your AUF to pick up warm air off the stack will improve your efficiency not by a huge amount but it will help if it's easy enough to configure. My blower enters the back of the firebox to prevent any tripping hazards while walking around the evaporator. Adding a blower is the single easiest thing you can do to increase your boiling rate.

Most any blower will work for AUF, a lot of people use squirrel cage blowers rated between 150-300cfm. I'm using a 6" inline duct fan rated for 250cfm. You will want a rheostat fan speed controller or a damper setup to control the amount of air. Amazon has a ton of options for fans and speed controllers. If you want something today your local home improvement store should have everything you need on the shelf for a blower set up.

I'm going to be firing everything up this afternoon I have 50 gallons waiting to get in the pan and should get another 100 or so this weekend if it runs like it did last weekend. I'm looking to have temps in the upper 40's Saturday and Sunday.

I'm with you on the having fun, I never would have thought boiling water could be so entertaining and I used to operate a combined cycle power plant. Just wait until you get a tubing system and get excited watching the bubbles move through the tubing. I'm sure my neighbors think I'm nuts standing their staring at the blue tubes in the woods.

[Lilshot]

I was able to get 21 more taps out today. Sap was running out the hole by the time I got the drill set down. Makes 63 so far and got permission from neighbor to tap 6 big sugar maples along a common fence row. That will make 75, should keep me busy. Looked like most trees had about a half gallon or so in the sacks from today. Ought to be a pretty good haul before the weather shuts em down on Monday. I'll try to gets some pics when I fire up the evaporator again.