Trouble with Boil

[SeanD]

I had my first boil on Sunday, but it took a lot longer than I had hoped with my new set-up. My front two pans raged while my flat back pan never really got to a boil at all. At times the front of the flat pan would just start to boil, but that was about it. I could even give the stack a quick tap with my hand. It seems the heat is just not moving back there. I tried a bigger fire which helped just a little, but it nearly carmelized what I had in my front pans.

I'm kicking myself for not having finished picks of the inside, but basically the firebox is about 20" deep and then I quickly slope it up and run it flat all the way to the back about 5" inches below the big flat pan.

Can I improve on this by raising the arch in the back to within a few inches of the bottom of my pan? I know those of you who have flue pans get right up there. Will that help me out here or am I expecting too much out of my little set-up.

Below is a pic of the arch mid-construction (I forgot to take a picture of the inside when it was done.) and one of the pans set up on top.

As always, I greatly appreciate the advice.

Sean

[RileySugarbush]

Sean,

Nice looking arch! It sounds like you are very close. I think you are right about the flue area. There is no reason to make it have any greater cross sectional area than the stack. I'd fill the slope right up to within 1.5 inches of the flat pan, straight up from the back of the firebox. All the heat in the flue gasses below about an inch from the pan bottom are being wasted.

Also, you might want to seal up any leaks up front around the steam table pans. It may be that the draft is sucking too much cool air in. On my old block arch, I used some pieces of galvanized rectangular ducting that comes in too l shaped pieces, and used them to form the insides of arch walls to help seal it up. The steam table pans will hold them in place.

Let us know how it works out.

[maplehound]

Are you getting a good draw up the stack? You will need 2 feet of rise for every foot of run ( length of arch). It might help to get closer to the bottom of your pans, at least at the front. How air tight is this set up along the run. You might need to tighten it up some.

[peacemaker]

i would do a cpl things bring it up closer to the pans minium 3 inchs but i also would lay something over them rocks like sand if some of them start to pop you could have a heck of a mess ... and maybe go a 8 inch stack ... what do u have for draft is that your draft all across the bottom ?

[Brent]

sounds to me like not enough draw
could be you need more stack height
could be you need larger diameter.
If it is 6" I think the diameter is too small for such a long set of pans.
Simply not sucking the fire back far enough fast enough.

[SeanD]

I am using a 6" stack that's 6 feet high. The rocks are just a base fill. I have bricks and sand bringing it up and flattening it out.

It's true there are leaks - mostly wisps here and there, but they probably add up. The steam pans ended up needing to be raised on those red bricks because the front one hung into the doorway. I'm sure if I dropped them down it would seal it up tighter, but I'd lose a little access to the firebox.

I'll try to snug it up and raise that back part of the arch. Thanks for the ideas.

[royalmaple]

When I used steam pans, I let you in on a little helpful hint. Drill two holes on each side of the outer lip of the pans. Towards the 4 corners. THen take a coat hanger and make two loops, one on each side. Bend it up or twist it up under the lip and you'll have two handles that will save you from getting burnt. It's not perfect but better than trying to lift those pans off if you are getting too far and need to get them off in a hurry.

[TapME]

You don't have enough draw up the stack and the height may be an issue as has been said. With mine I have an 8'' on a 2 ft. wide arch. Even with the leeks in the blocks if there is enough draw it will not be a problem. also it look like you may want to control your air intake a little, I have done that in the past also. It should sound like a freight train is running buy you when the draw is right. Good luck and great looking arch.

[RileySugarbush]

Here's a quick thing you could try.

Move the steam table pans to the back and set them right down in the arch so they have a small gap to the bottom of the flue section. They will act like two drop flues, though admittedly they will not be full to the top like real drop flues. If you run your raw sap into to those and never let it get very close to syrup, the low sugar concentration will minimize burning on the hot pan sides. Ladle out of those as required to keep a good level in the flat pan up front as a syrup pan. The flat pan will let you have good access for firing and will have cool side walls so you don't get burning as you finish. You could add a draw off valve and even some dividers to that front pan in the future.

If that works out ok, I would think about adding a cheap blower to force air up through the grates and tightening up the front a little. I bet you could exceed 10gph.

[WESTVIRGINIAMAPLER]

If you could push the gap up to about 2" between the back pan and add at least 6' more to the stack, you will be in good shape. I will have to disagree, I think 6" is sufficient enough draw. You make need to squash/flatten the stack where it is in the arch wall. What I mean is to make it wider and not as tall will help pull the heat more evenly thru the arch. I used to boil on a 5x7 four section stainless king syrup pan and with two 6" stacks side by side in the center of the pan, I could do about 50 gph after I got it hot. If you could add 9' to the stack and put a damper in the stack as they are cheap that way you can play with it and cut it back a touch if you are sucking too much draft. I boiled on cinderblock arches for years and they work great and you are on the right track. Those two adjustments which should be cheap and easy, and you are good to go. Contrary to what others might say, I don't think you lose that much heat out of the sides of the cinderblocks as the airspace in the center helps insulate.

PS Leader sold a 2x6 evaporator for years with 7" stack and it drew good.

[mfchef54]

I have the opposite promblem. My second and third pans boil before front boils. have two sheets of tin for front. If I leave the top sheet off it works fine, but then it's hard to control back pans.
Sean, how did you attach the front? Looks great, did you make it yourself?

[WESTVIRGINIAMAPLER]

Maybe you need a tight damper in your stack to just adjust it slightly and that should fix the problem or else have some way of controling your draft on the front.

What I mean by tight is one that has a spring on it and you can adjust it slightly and is not moving loose that you can't adjust it. It will need to probably be open 80% or more, just slightly closed.

[SeanD]

Man, I thought I was good with the stack height. I'm not sure how to make it even taller without the danger of a good breeze taking it over. Do you put sheet metal screws between sections? Right now they are just tucked inside one another and a little (a lot) wobbly. How do you secure the base? Right now I have a 3' metal stake wired to the back of it and weighed down with a cinder block.

Matt, good idea on the looped handles on the steam pans!

mfchef54, I did make the front myself, but I stole the idea from John Bushey. He has pictures of his block arch he used to use. The front hangs on the blocks by two L or corner brackets screwed on each side. I can send you pics of the process if you are interested. Send me a PM.

John, that's a good idea reversing the pans and an easy fix, but I'm trying to reduce the volume of sap I have to bring inside to finish. When I get down to 1" in my 2x3 pan that's still almost 4 gallons and I'm cutting it close with scorching because I have some high spots in the pan, so I have to keep it a little deeper. In this method, when it all concentrates to about 3 inches in last steam pan, I know I have three gallons to take inside.

[WESTVIRGINIAMAPLER]

Yes, you definitely need to increase the stack height to at least double what the length of all your pans combined. Screw it all together good with about four sheet metal screws in each section where it joins together and then drive in a 7' steel fence post aprox 18 inches in the ground that and wire it really good the the fence post. They drive easy and should only be about $ 4 and hold really good. If it is all screwed together and about 30 or 40 percent of the bottom wired tight to the post, you will have no problems. Do this and push the heat up within 2 inches of your pans and you should be amazed at the difference.

[RileySugarbush]

Sean, if you can divide your pan into serpentine channels, and add a valve, you can ladle into one end and draw off as the syrup finishes. If you don't want to add a valve, you can scoop out on the finish end. When you are done for the day, let the fire go out and cover up the pans. Let it set until you are ready with more sap. it's not quite as smooth as a full blown evaporator, but it will work. The dividers don't have to be perfect, just some sheets you can c-clamp to the pans sides with openings on opposite ends for the syrup to flow.

I ran a rig like yours (except all steam table pans) for years and always in a batch manner. I sure wish I'd realized I didn't have to finish it all each day. Sure would have saved a lot of cleanup and finishing time, and saved some ridiculous hours when the weather turned bad.

[SeanD]

I definitely think sections will be my next upgrade, but it will have to wait until next year. I have to try to remember to get going on this stuff when it's warm and sunny in July, not weeks before the season in my cold basement.

I raised up the arch under the pan to about 2 inches and it improved the boil in the back pan a bit in my second boil today about one more gph to 9 or so. I didn't have time this week to get any more sections of stack, but it definitely feels like that should do the trick.

Right now I have a short fence support wired to the stack to hold it steady. It's wedged into a cinder block on the ground with a chunk of wood. The ground is still rock hard, so there's no hope of pounding anything bigger into the ground. I'll get a taller fence post with the higher stack, but I'm a little worried about supporting it. I'll try jamming it into a cinder block the way I do now, but that's only 8" of 7'. Anyone have any good ideas for a support for a 7' fence post?

Thanks for all the advice,
Sean

[OGDENS SUGAR BUSH]

can you wire your stack off to the roof or side wall??

RICH

[Big_Eddy]

I attached 3 wires to my top pipe section, then tied a rope to each, anchored to a cement block 1 behind, and 1 off to either side. The one behind and off to one side are not a problem, the one to the other side I hang some flagging off so I don't hang myself when I'm stoking. My stack has held up in extremely high winds - strong enough to blow a wheelbarrow across the yard. A lot simpler than trying to anchor it to a stake.

I screw my sections together, but the screws never hold up till the next season and I don't bother replacing them. Once the stack is up, the guy wires hold the pieces together.

My door is a little lower tech - I have a piece of (once flat) 16 ga steel that I slip behind a couple of blocks to close off the front. It has worked well enough for 15+ years. I'll take some pictures once I get set up for this year. Just cleared the snow off the spot yesterday - now need to let the ice melt off before I place my blocks.