Bad mistake and close call

[johnpjackson]

Last night I really screwed up. I'd been boiling on my home made evaporator since 7:30am. I had ~120 gallons of sap to do. I kept at it non-stop. Around 3am or so I was almost done and figured I had about 3 gallons of almost syrup in the pan. It had gotten down to about 14 degrees outside by then and I'd been going in the house in between adding buckets of sap to the evaporator about every 20 minutes or so. The evaporator is inside a little room in the attached shed between our house and barn. It's fired by the biggest turkey fryer style propane burner I could find. It's enclosed by cement blocks that my pan sits on top of.

Anyway, despite my promises to myself to be vigilant, I ended up falling asleep in the house for about a half an hour or so. When I woke up I panicked because I knew I had been asleep and longer than was going to be survivable. When I opened the door into the shed area I smelled the burned sugar. My heart sank and it hasn't really recovered yet. The first thing is, I am so lucky I didn't sleep longer. I can't see how the contents of the pan wouldn't have caught on fire soon enough. What I found was that the syrup had boiled over the side of the pan and onto the floor, more than a gallon of it. It reminded me of the Elephant's Foot of nuclear fuel molten glass in the basement of the Chernobyl reactor building. What was still in the pan had begun to turn into a black, carbonizing disaster. I immediately shut off the propane burner and then dumped a couple of gallons of freezing cold sap into the pan to get it cooled down. After that I did a little basic cleanup but left the mess for this morning to face. After that whole day of boiling, and all the work my family and me had put into getting those first 120 gallons of sap collected, all I wanted to do was just go to sleep and get away from the shock for a while.

Today I dealt with the ruins in my evaporator pan. The pan is (was) a beautiful piece of work I got for a few hundred dollars from a guy in Michigan who makes them. 21" x 24", divided into 3 troughs, with bulkhead fittings for a draw off valve and thermometer. Plus, a little warming pan that sits on top of one end of the troughs. I used to be worried about doing anything potentially rough on the pan as far as cleaning it, based on how careful it looks like people in videos online and here in places like this sound about it. I had to give up that ethos. The burnt on, carbonized sugar in most of the inside of the pan was indescribably bonded to the stainless steel. I spent 5 hours getting it all removed. After getting the initial sugar goo off everything, I eventually decided there was no way I was going to get the carbon off without scratching the metal. I settled on a razor blade scraper and tried to minimize the scratches and gouges with it. After I got through it all, down to every little bit everywhere, I used an industrial scotch brite type of abrasive pad to sand/clean the whole interior surface. That smoothed out the discernable feeling scratches and gouges, and it took off the bluing that the overheating had caused to surface metal.

The lasting effect of the overheating though was that it warped the bottom of the pan pretty badly. It's pretty wavy looking now but it is still just as solid as ever and will hold and boil sap, I'm sure. Other than looking shabby and abused for that, is there anything about the pan being warped, or having needed to be scraped out so extensively, that will negatively impact my syrup making with it now?

:(

[Sugarmaker]

Let me the first to congratulate you! You are now officially a sugarmaker!
You may notice my handle, and yes i was not the first or the last one to scorch a pan. You did a good job recovering!
The pan may need to be boiled a little deeper to make sure you can cover any high spots.
You can now proceed with your syrup adventures and count your lucky stars that you did not burn the place down.
In hind site stop boiling when your tired or have someone with you who is wide awake.
Your next syrup will be just fine!
Regards,
Chris

[Twisted Minds]

I've been there, long days working, collecting, transporting and long nights boiling. We've all done it. That being said, my operation is open air, with a wood burning evaporator and pan large enough I always keep enough sap in that can't get away form me just in case I do doze off, fire will go out before pan boils off. To be operating with an open flame propane burner in an enclosed building, attached to the house, you're lucky it didn't catch fire boiling over. We've all seen the videos off dropping turkeys into fryer too quickly and instant inferno. I'd be more concerned with flame going out and building filling with gas and . . . . well a scorched pan would be least of your worries. Never leave a gas flame unattended.

[Sugarbush Ridge]

Stainless steel ,,, or an iron pan????? To polish it up, blue scotch-brite and then go to a janitor supply store and get the 'white' floor polishing pads to get the scratches polished down. You can get the 'white' in squares.

[buckeye gold]

yup you are official now. Run your sap deeper and move on as a pro. There are those who have burnt pans and those who are going to, those are the only two categories in syrup making.

[mainebackswoodssyrup]

Yup, you’re the real deal now. Run it a little deeper as others have suggested and keep an eye on it. It will probably still make good syrup. What seems like a disaster will make a great story down the road. Chalk it up as a lesson learned and another memory made :)

[Z/MAN]

We have all learned the hard way to never leave that pan unattended. My lesson was on my first ever boil and I wanted to cry. If you ever have it happen again, to prevent scratching the pan, pound a piece of copper tubing flat on one end and use that to scrape the pan. Copper is softer than stainless and will not scratch your pan.

[LMP Maple]

I am sorry to hear this and as the others have said be thankful that the house is still standing and your family is safe as all else can be fixed/replaced. As a motorcycle rider told me years ago its not a matter of if you go down on your bike its when, likely from a car driver making a mistake. The same holds true for scorching your pans, its a matter of when not if.
The first thing I would tell you is try not to dwell on it too much. It sucks for sure but it happened and you have moved on. The next thing I would tell you is invest, and its a small investment, in an r/o for next year. This will take those marathon boils down to 3-4 hour affairs and improve everyone's life by leaps and bounds. I had a marathon boil on my first night until 1:30 am. I took the sugar up to 4% but had I taken it to 6 I would have been done at 11:30 or earlier.
I would also say thank you for sharing this as it can be hard to post something like this. Getting this information out to everyone is very important as we all can learn from this from the person starting out to the seasoned veteran.

[82cabby]

Sorry man. I’ve scorched a pan as well. Ruined a whole weekend’s worth of boiling. I feel for ya.

[BCPP]

I've been there, long days working, collecting, transporting and long nights boiling. We've all done it. That being said, my operation is open air, with a wood burning evaporator and pan large enough I always keep enough sap in that can't get away form me just in case I do doze off, fire will go out before pan boils off. To be operating with an open flame propane burner in an enclosed building, attached to the house, you're lucky it didn't catch fire boiling over. We've all seen the videos off dropping turkeys into fryer too quickly and instant inferno. I'd be more concerned with flame going out and building filling with gas and . . . . well a scorched pan would be least of your worries. Never leave a gas flame unattended.
Sorry to disagree, little to no chance of the boil over catching fire. Sugar is not anywhere near as flammable as oil! When it boils over it returns to a solid as soon as heat is removed. The stuff that keeps getting heated will smoke a lot, smell awful and leave behind the carbonized mess that he found.

[johnpjackson]

You guys, thank you very much for the words of support and letting me know I'm not all that alone on this one!! I hadn't been thinking much about this being a mistake or misfortune that many other people have experienced. You actually helped make me feel a little better about picking myself up from it and cleaning up for a new effort! :D

I've never been comfortable with running the evaporator inside the building but I don't have a good enough alternative to it, yet. I'm going to work on that possibility for next year. For now I've tried to make the spot it's in as safe as I can think of. Last year I just had some pieces of sheet metal forming a square around the burner to keep more of the heat closer to it and under the pan. Still, the room was pretty crazily hot inside because so much of the burner's heat was just missing the pan. This year I built a whole firebox around the burner with cement blocks. And I made a mount for the pan on a square piece of sheet metal big enough to cover the whole top of the firebox. Then I cut out the sheet metal a 1/2" smaller than the footprint of the pan. This keeps as much of the fire from the burner inside the firebox as I want. The room is so much cooler now I have the new problem of the steam from the pan condensing on everything inside. I have an exhaust fan in the window drawing the steam out, too, and it was having problems with condensation freezing on the fan blade shroud and getting clipped by the blades.

While the new firebox is much better than the lack of one before, I discovered it needs more work. I've realized I need to give the firebox an adequate way to vent because now, the propane is not able to burn efficiently enough. I'm able to see the flames from the burner have a lot of yellow, and are creating a lot of soot. And, worse, the carbon monoxide detector I put in the room confirmed that too much of that gas is being produced. I actually think it's possible that my late night sugaring narcolepsy the other night could have had that as a contributing factor. Running the exhaust fan keeps the CO detector from finding a problem but, when I am adding sap to the evaporator I'm also getting more into the path of the air that it's pulling out of the room. My plan is to build a vent manifold out of sheet metal to integrate into the back wall of the firebox. I'm going to make a stack attachment on it for 6" stove pipe, and pipe it out the same window the exhaust fan is using. At the same time, I'm going to make the top of the manifold have a place to set my warming tank into, instead of resting on top of the evaporator pan troughs the way it is setup now.

I can see how this process I'm going through is re-inventing the wheel. By the time I'm done, the few thousand dollars I could never imagine spending on buying a 'real' evaporator will seem like it could have been a better and easier choice. Although, I haven't actually seen yet anyone selling evaporators that are propane/NG fired?

Also, I am going to have an additional safety scheme created before I do any more boiling. I'm going to add basically a dead man shutoff for the propane burner. For about $40 I'm getting both a solenoid operated gas shutoff valve and a countdown timer switch, both 110VAC, plus an ordinary light switch, that I'll use to make that. The ordinary light switch will be used to keep the gas valve powered on/open when I'm around and alert and not worried about the possibility of the boil getting left unattended too long. The countdown timer switch will also be able to supply power to the solenoid. If it gets late and I'm worrying at all that I could accidentally nod off or anything else, I'd use the countdown timer switch to keep the gas turned on. I'd turn off the regular power switch beside it. In practice I could hit the 20 minute countdown on the timer, turn off the regular switch and walk away. If I don't come back in 20 minutes and either re-up the timer or turn the regular switch back on, the gas valve will shut off and the boil will stop. I got this idea from realizing that the wood burning evaporators have this behavior built in, basically. If you stop feeding them wood, your boil will go away as the fire burns down.

Nothing is perfect but if I'd had a timer setup like this on my burner the other night I might have had less of a disaster, or maybe no disaster.

Our trees here should be running these next several days. I'm looking forward to getting more sap and a new chance for some syrup happiness for my family and me :)

[DrTimPerkins]

I find the idea of walking away from a running evaporator, however it is fueled, a concept I just can't wrap my head around. It just doesn't seem like a good idea to me...kind of like crawling into the backseat of a car you're driving down the interstate at 75 mph while it's in cruise control. Even when the evaporator operator leaves for a minute to take a leak or check a tank level they yell out to whoever is in the sugarhouse they are stepping away and that person immediately goes to the evaporator to "babysit" while the main operator is not at their station.

[johnpjackson]

Dr. Tim I don't disagree with that thinking at all. I agree with it, really! If I had anyone else available in my little sugar room to do that for me I'd use them for sure. I just don't have that all the time. I will come as close to it as I can come up with, is all I can think to say. My only other choice would be to just not do it at all, potentially. But again, I'm not saying you're wrong, at all.

[BCPP]

I find the idea of walking away from a running evaporator, however it is fueled, a concept I just can't wrap my head around. It just doesn't seem like a good idea to me...kind of like crawling into the backseat of a car you're driving down the interstate at 75 mph while it's in cruise control. Even when the evaporator operator leaves for a minute to take a leak or check a tank level they yell out to whoever is in the sugarhouse they are stepping away and that person immediately goes to the evaporator to "babysit" while the main operator is not at their station.
I agree, but when you're a one man operation on a wood fired evaporator and nature calls you have no choice! Best I can do is make sure I'm there as much as I can. Murphys law requires that if anything is going to go wrong it will happen ten seconds after you leave!

[TheNamelessPoet]

I find the idea of walking away from a running evaporator, however it is fueled, a concept I just can't wrap my head around. It just doesn't seem like a good idea to me...kind of like crawling into the backseat of a car you're driving down the interstate at 75 mph while it's in cruise control. Even when the evaporator operator leaves for a minute to take a leak or check a tank level they yell out to whoever is in the sugarhouse they are stepping away and that person immediately goes to the evaporator to "babysit" while the main operator is not at their station.

Hence the #1 reason I use propane... so I can go to the bathroom. I am the only one doing it, and I am not ready to trust my 5 year old around the pan yet lol.

@Johnjackson, I may not have burned one the same way, but I am PARRANOID about it. I burned a $20-30 pan I got on Amazon my 1st year, and it wasn't even really my fault. But I am going to hope THAT was my burned pan story (not the soup I fell asleep "watching" when I was a kid and ruined my Moms favorite pan and my Dads favorite soup!)

Glad to hear others stories have helped, because we ALL have a similar one about burning a pan, or we just haven't written it yet.

[BCPP]

I'd also point out that you can burn the pan even if you're there watching it. If you're running your finish pan shallow and the feed float sticks just as it starts foaming reaching syrup point (Murphy's law!) the pan will burn within seconds and you really only notice it when you smell burnt sugar!

[DRoseum]

I built a couple safety features into my nat gas evaporator when I was doing batch boils in a flat pan.

(1) a level sensor to close a normally closed solenoid on the gas line when level drops too low using a GRL8-02 controller and a drop out switch to prevent re-energization of the solenoid
(2) a temperature controller (similar build to autodrawoff) to also drop out power if you go too far over temp.

The power output of the temp controller is what powered the level controller so if EITHER condition occurred it would shut off the gas until I do a manual reset of everything.

I now run a continuous flow flue pan set. The level controller senses my head tank and the temp controller became my auto draw off.

For the small price in parts... its worth building these safety devices to prevent major disasters.

I'll try to post pictures/videos if interested.

[DrTimPerkins]

I'd also point out that you can burn the pan even if you're there watching it.

The increase in sap/syrup density doesn't happen linearly...it is exponential. So for example, if it takes 2 hrs to go from 2 to 8 Brix, it'll go to 16 Brix in one hour, then 16 to 32 in 30 min, then 32 to 64 Brix in 15 min. Things accelerate as the density approaches syrup.

There's lots of ways a scorch can happen and it is difficult to maintain concentration during long boils. We have a series of checks and scans we're constantly doing during evaporator operation to make sure things aren't going south. That routine alone has saved us a number of times. Everything is set up so we can see all the key parts from the operator position near the drawoff, including levels in various tanks and vacuum level. We use a "Protect-o" in the front and back pans as a safeguard also...just in case we don't catch it quickly enough. For places we can't easily see (RO room, overhead tanks) we have cheap security cameras set up with the display right near the evaporator. Overhead and remote tanks have electric ball valves we can turn on/off with switches from the operation station also, so no leaving to climb and ladder and turn on a valve. Lastly...just in case there is a problem...we always have a spare front pan.

Not saying those things are what everyone should do, but just that close attention is important to lessen the chance of burning your pans.

[PCFarms]

Oh that heart sinking feeling, I know it too well...

The time I came to a sap tank that should have been full but had fallen off its supports and broken the drain valve...
The time the float box on the evaporator had debris in it that clogged it the tiniest bit open overnight and the entire concentrate tank drained out through the evaporator into the trench drain...
The time I found a burnt VFD... (fortunately it was only the VFD and not the pump house. I still have lingering imagined thoughts of coming to a pile of ashes when I approach that pump house and I think, thank goodness its still there, today could have been worse)

My consolation is that these mistakes happen less and less often with every passing year - It hasnt't happened in the last year or two.

[DrTimPerkins]

Oh that heart sinking feeling, I know it too well...

That's a big part of actually making money in maple...limiting mistakes. Considering that there are only 5-6 GOOD sap runs in a season and maybe another 5-6 fair sap runs, then losing just one of them has a big impact on your total production and can make the difference of putting some money in your pocket or pulling your checkbook out of your pocket.

[mass maple]

I lost a run my 1st year so I know it sucks. I had a pan over a grill and I went in the house when it was lower and almost syrup, bad idea. This week I was boiling in my barrel set up with three hours sleep after another night with 5 hours sleep. around 2 am I was sitting in a chair watching it and it was nice and warm form the fire. I was nodding off so I pulled the warming trays and put the sap inside the basement.

[johnpjackson]

I got back on the horse last night, finally. We had a break in the sap running for a bunch of days and I used the time to add the dead man timer and shutoff feature to my setup. That turned out very well. The propane flows as long as either the manual on/off switch or the countdown timer switch is turned on. If you leave the manual switch turned off, then the timer switch will shut off the propane valve when whatever countdown time you set it to runs out. I was using it when it got late last night and I was fighting off falling asleep. 20 minutes is about when I need to refill my warming tank, each time. The scheme worked great!

[Sugar Bear]

The one great thing about letting unattended syrup blow up is that after you do it one time you will likely never do it again.

[johnpjackson]

I did go to sleep last night instead of boil. I was too tired from the night before, boiling all night, to trust I could do it again last night..

[red/one]

The difference between we are good and uh-oh. Last nights boil became panic when I thought the float box was set right but it was not. It looked good for the start up but then the temps started to fluctuate and I opened the draw off and a trickle came out. It got to +11 before I could fill an uh-oh bucket. You dont have to fall asleep to have a bad day in the saphouse. :lol: You have to be on your toes for sure.

[DrTimPerkins]

OK...I know I've said it many times, but things happen really quickly once you get close to syrup. Here is why...let's assume 4 gal/hr boil rate on a small rig.

To go from 2-5 Brix, you have to boil off 26.5 gal of water (6.3 hrs).
To go from 5-10 Brix, you boil another 8.8 gal water (2.2 hrs)
To go from 10-30, you boil off 5.9 gal water more. (1.5 hrs)
To go from 30-60 Brix (close to syrup), another 1.5 gal water (0.38 hrs or 22 min).
But to go from 60-67 Brix, you only need to boil off another 0.2 gal water (0.05 hrs or 3 min). Happens in the blink of an eye at the end there. Takes even less time to go from 67 Brix to black char. Kind of like a steam-roller rolling down a steep hill...except the steam-roller will eventually reach peak velocity (based upon the steepness of the hill and the friction with the road). The evaporator has no peak velocity...it just keeps going faster until it all turns black and the sugar catches fire.

So in that total of 10.4 hrs of boiling...not paying attention in the last 3 min can really turn things into a bad day quickly.

[therealtreehugger]

OK...I know I've said it many times, but things happen really quickly once you get close to syrup. Here is why...let's assume 4 gal/hr boil rate on a small rig.

To go from 2-5 Brix, you have to boil off 26.5 gal of water (6.3 hrs).
To go from 5-10 Brix, you boil another 8.8 gal water (2.2 hrs)
To go from 10-30, you boil off 5.9 gal water more. (1.5 hrs)
To go from 30-60 Brix (close to syrup), another 1.5 gal water (0.38 hrs or 22 min).
But to go from 60-67 Brix, you only need to boil off another 0.2 gal water (0.05 hrs or 3 min). Happens in the blink of an eye at the end there. Takes even less time to go from 67 Brix to black char. Kind of like a steam-roller rolling down a steep hill...except the steam-roller will eventually reach peak velocity (based upon the steepness of the hill and the friction with the road). The evaporator has no peak velocity...it just keeps going faster until it all turns black and the sugar catches fire.

So in that total of 10.4 hrs of boiling...not paying attention in the last 3 min can really turn things into a bad day quickly.

I have always understood the general concept, but it really drives it home when you put numbers to it! I didn’t realize it could happen that fast!
Thanks Dr. Tim!

[richwilly]

I was once helping son with school work when got a whiff of the smell of something .went out to garage where i was boiling to a filled garage of smoke.smoke billowing out of open garage door ,someone had pulled over i waved like nothing out of ordinary here smell lingered for a few weeks.