My oil tank arch build

[crzypete]

I was immediately attracted to the oil tank arch designs pioneered by many. I love the repurposing of an object and was able to get a free tank from my neighbor.

My build began last summer, but I of course dropped the ball and had to crank it out over the last week.

I have a pretty complete shop and tasked myself to make the pan as well as the boiler. I press braked the long sides of the pan and welded the ends. My welds on the first end of the pan are pretty ugly, but after some excellent advice at the welding supply store, I saved my good name on the second end.

I test ran it today for the first time and am quite pleased. No time to waste, will be making syrup tomorrow.

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[crzypete]

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[crzypete]

I got the order of the photos a bit screwed up. Sorry about that, Here is the rest of the build

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[crzypete]

And one last little sequence, because this made me happy, I always wanted to layout a union of two different sized pipes. It took some serious studying of my 1950's sheet metal book to fully comprehend the process, but I was very pleased with the result. This is made from part of the oil tank and rolled on my slip roll.

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[wobbletop]

Very jealous. Great work.

I have seen here that people will put the fire grate in the opposite way to yours. They say the ash held in the bottom of the "V" will help prevent the grate from warping.

[NhShaun]

That is one of the finer oil tank evaporators I have seen, nice work! I especially like the door design and the stove pipe collar. I agree with the last post, I tested my grates both ways and found them to be less likely to warp with the grates flipped the other way, especially with the extra heat the blower creates in the Firebox. Hope that thing boils good either way, talk about under the gun on a project. Do you have a pre-heater of any kind ?

[crzypete]

Thanks guys. I actually had read about using the grate with the V's pointing up and welded it such that I could use it either way. The reasoning I had read was that it held coals better with them pointing up, but my gaps are small enough that I figured it wouldn't be an issue, didn't read about helping to prevent warpage, I'll have to flip it next time I'm in there. Unfortunately, the fire bricks are sitting on the grate, not a perfect solution, I may have to trim the grate to alleviate that.

No preheater.....Yet. I have been observing the designs that are out there and will probably add that to my list for next year.

I'm also not sure about the blower being properly situated, it's far from the fire on the stack side. It definitely makes a difference, but is it as effective as it could be? I don't know.

I made 3 quarts of syrup today and blew through my entire supply of sap. I need to tap more trees tomorrow to feed this thing. 24 trees currently tapped.

Pete

[brocken]

quick question, what are the two holes under where the angle grinder is sitting in picture #11?


dave

[crzypete]

they were threaded bungs from the original oil tank. That used to be the top that I had cut off. I welded them shut during my build.

Pete

[SSS2017]

Looks really good!

[crzypete]

I had an inquiry about how things were going on another thread and have decided to paste my response here as well. I'm really enjoying this thing!

I've been really pleased with it. Actual rate is a bit hard to determine as it really depends how hard I push it. I've gotten more aggressive in adding wood and it has definitely responded. I easily hit 10gph when I am stoking it hard.

I suspect a preheater for my sap will increase that rate- I'm debating the best way to build this for next year- thinking of a split pan so I can heat one side while I am filling from the other side, but this may be way overkill.

I'm also thinking that the ramp may benefit from being closer to the pan, I was planning on insulating that area, but haven't gotten to it- I'm planning on experimenting with some firebrick and sand to see if that makes a difference. I'm happy with how I built it though as it is pretty easy to move it up, but it's hard to move it down.

Things I did right- make the fire box deep enough to get a 16" piece of fire wood in straight. I find that I cross stack and having the ability to go straight in makes life easy.

I'm still not certain whether my blower should be closer to the fire or a bigger blower. It certainly makes the fire more intense, but I'm not experienced enough to tell what would make it even better.

The pan is 26" x 48" no dividers. After reading much about continuous flow, I am convinced that this is the method best for me. Continuous flow just seems overkill for my operation (36 taps this year, but enough maples to go up to 50 if I desire).

All in all I absolutely love it and its completely great for my operation. I am scheming on upgrades for the fun of further construction more than the need for higher efficiency.

Peter

[brass maple]

Crzypete
run a 2 inch metal pipe from the back to the front through the hole you cut. On the end of the pipe that goes to the front of the barrel make several short cuts on the end of the pipe and bend them over to plug the end of the pipe. Then on the top of the pipe drill 3/8 holes in three different lines down the length of the pipe only under where the fire will be. One line right down the top of the pipe one line at 11 oclock position and one line at the 1 o'clock position. On the other end of the pipe hook up the blower. It works well. Done this way you don't get a lot of ash blowing out of door when opened and you have the air aimed right where you want it. My blower is a leaf blower and it doesn't blow any thing out door with that much power, It will increase the heat in the wood chamber considerably. If you don't already have one fix a plate of metal that fits over the opening of the air Intake of your blower and put a screw in a spot that wont interfere with the fins of the blower so that you can open or close it to control how much air you are pushing through the grates.

[Austin351]

Crzpete- With exception to the fire door, your build looks exactly like the evaporator I built last season.


https://www.youtube.com/watch?v=Srfksbj39Hk

[crzypete]

Matt, Thanks for the piping idea. What are you using for pipe? I can't imagine listening to a leaf blower while boiling, ditto all the guys using shop vacs.

Austin, looks like a nice build. Love these oil tank evaporators!

Anyone have ideas towards a pre-heater? I am having grandiose ideas of a contoured stainless pan that sits on the top curved area of the tank and has a hole for the chimney to pass through. Why? because it sounds like a fun challenge to build and would look cool. Functional? Maybe? Stupid? Definitely!

Pete

[wobbletop]

I use a bathroom fan. Probably around $30 at home depot and not very loud. Add a speed controller for maximum adjustability.

[billschi]

This is the one I made last year.
https://youtu.be/oNUk0AQvoeU

[northwood]

Very similar to the one i have as well. I have one large flat pan (22 x 34) and one 12 x 22 finisher. Also have room at the back for 2 large stock pots for preheating. Last year I added a small quiet cage fan connected to the 2" hole under the front door. I went from 6-7 gph to easily boiling away 10-12 gph. The fan blows about the same amount as a hair dryer, but really keeps the fire hot. (and no buildup of coals) If I have to step away for a bit, I load up the unit with wood and sap, unplug the fan and it would simmer away with no worries. Mine is fire brick front end with a ramp to the stack. Short of buying a drop flue pan, not much more I can do to increase the gph.

[Sugarmaker]

Nice build! Probably what I should have started with!:)
You did the right thing on the big flat pan. getting gradient on a pan this size is not always easy.
Regards,
Chris

[Mendhammaple]

Hey Pete - this is my second year of sugaring and am looking to increase production by building an oil tank evaporator. Great pictures! I have a question for you. In the third picture of the inside there are holes drilled into the metal. What are those for? Do you have any hints or tips for making a successful evaporator?

Thanks!

[crzypete]

I think you're looking at the photo with the two large bungs that were originally part of the top of the oil tank. I eventually welded them shut. I really tried to use as much of the tank as possible.

My biggest tip would be to design the fire box around the size of your preferred wood length. You'll want to be able to get them straight in easily. the fire is so unbelievably hot there is not much time for messing around when you are loading it. If I didn't wear gloves when I was loading it, I would burn off my mid-digit hair.

I wish I had a bit more of a lip from the bottom of the door to the grate- it would hold the mountain of coals in a bit better.

Otherwise, I'm pretty pleased with the result. I'm planning some tinkering for next year, but this was the big hurdle. First and foremost is a pre-heater. I've been scheming on some fancy sheet metal ideas, but think I my be over-thinking it.

I'm also tempted to build a drop flue because it looks like a fun build project- I have been scheming on how to bend the flues with my press brake. But I suspect time and energy will get the best of this scheme.

My season total ended up being 10 gallons of syrup this year! A very nice improvement on last years 3 gallons. I pulled my buckets yesterday and called it a year.

Anyway, good luck with your build and ask any other questions you have, I'll try to help.

Pete

[Austin351]

Hey crypete, check this rig out. It was made by Billschi up in northern MN. 6' pan, used excess steel from the tank to extend the arch. Although I will want the stack coming out of the top, I think I'll have to build another one this summer based off this design...

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[crzypete]

That's a cool variant. I think I'd be tempted to do some sort of dropped flue if I increased the size- partially for the sheer entertainment of bending and welding a crazy zigzag pan.

I'm really in need of a pre-heater for mine. And possibly more air added to the fire. I found that when I really had it going the smoke wood be blackish rather than clean. My friends and I were debating whether it was carbon burning off the bottom of the pan or fuel not being thoroughly combusted. I think I'm leaning towards incomplete combustion. Debating where I need to add more air.

My season was a huge success for me. 10 gallons of syrup made and it was extremely enjoyable using this rig. I literally used up every mason jar in the house and had to go out and buy a dozen for my last batch- that is kinda nuts as I thought we had a ton of mason jars. My peak evaporation rate was ballpark 12 GPH, I didn't really calculate these things too perfectly, just let the thing rip and enjoyed the moment.

I'm mostly cleaned up for next year. I boiled my taps today and have cleaned the inside of my pan with a vinegar and water mix. Also used the copper scraper trick to rid one little burnt stripe on the back of the pan. Just need to clean the bottom of the pan clean the ash from the bottom. Also I'd like to add some fork pockets so I can safely move this around with my Kubota.

Any preheater pics would be much appreciated. Also any thoughts on introducing more air to get a more complete burn

Pete
http://mapletrader.com/community/attachment.php?attachmentid=18567
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[billschi]

Although I will want the stack coming out of the top, I think I'll have to build another one this summer based off this design...

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I have it coming out where it is because it sits under a roof without walls, like an open air lean to. This way when it rains, it keeps the roof from dripping into the pan. I did make it big enough so it can actually go out the top if I actually make a designated sugar shack in the future.
I fired it up Thursday and it worked very well, without the blower fan.
A friend of mine just brought a steel tray for me today. This tray will enable me to place brick on top and the fire to pass underneath so I can evaporate birch sap without letting it boil and burning the syrup.
Here's a pic of how I lined the arch with firebrick.
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[billschi]

[QUOTE=crzypete;355373]

Any preheater pics would be much appreciated. Also any thoughts on introducing more air to get a more complete burn
Pete

Pete, I don't think you need a blower fan.
I cut three 2" holes under the door of mine that allows air in under the grate. After you do that, add 10 or more feet of stove pipe. You will be amazed in the difference and you won't need to listen to a noisy fan.
The heating oil tank arch I built cost just about $400 and that was due to the door adhesive tape (for under the pan), firebrick and stove pipe.

[crzypete]

I boiled my first batch yesterday and wanted to share some improvements and changes I made to my evaporator.

Firstly, I made a preheater pan. This was as much to dribble my sap in rather than dumping gallons in. Also, as an entertaining bending and welding exercise.

Next, I lined the rest of my evaporator with some ceramic blanket from mcmaster carr. I'm hoping this will push the heat a bit closer to the pan as well as protecting my tank.

I added a section of stove pipe to extend my stack a bit- as per advice in this thread.

Lastly, I added a sealer strip between the pan and the angle. I used wood stove door sealer and the glue they provided to glue it in place. I found a flat product that gives me some latitude in positioning.

The boiling photo is my first batch this year- kinda a warm-up run. I didn't use the blower or the preheater pan due to a lack of sap. Made only a quart, and I have tapped fewer trees this year due to a looming work deadline.

Pete

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