Cement block evaporator almost done!

[valleyman]

Thanks for all the help and suggestions. I attached some pics of my evaporator almost complete. I have a stove door on order. I still need to find a piece of plate steel to fiinish off the front.

I built this in place of where I once had a fire pit and I had to promise my kids they would atill have a place for roasting marsmallows. Then it dawned on me. Why not make it a small pizza oven for summertime use. So I modified it so I can do both. It actually made a good pizza. See attached pic.

[Father & Son]

The most important part of what you said was the kids. They will remember that block evaporator/pizza oven all their lives.

Jim

[3rdgen.maple]

That looks pretty cool. I miss those days sometimes when things where simple and less of a job. Enjoy it with the kids.

[RileySugarbush]

Very nice! You will have lot's of fun with it

[Gary R]

Look's nice! Have a great time.

[PerryW]

Maybe I'm being over-cautious but ..

My concern would be that the portion of the pans that are above the sap level will be exposed directly to the flames.

How much of a gap is there between the firebrick and the SIDES of the pans?

Can you push the second row of bricks inward as much as possible to reduce the heat exposure to the side of the pans?

[valleyman]

Hi Perry,

The pans have about a 1/2" lip all around. I made the width of the arch so that the lip on the sides of the pans rests on 1/4" or so.

Probably a simple answer, but what's the concern if the pans above the sap get heated by the flame? Wont that just heat the sap all the more?

Yeah, I can move the sides in so there's a slightly snugger fit but the pans have a slight taper so the sides will be exposed to a certain degree. I was wonderring about having the width so that the pans sit on top, but keeping this design seemed to keep them real stable.

I would like very much if I can lift the pans up and out quickly. With the current design, I have to ladle the liquid out, not pour it out when the sap in the front pan is ready to be finished. How expensive if its feasable, would it be to weld handles onto my pans?

[3rdgen.maple]

Good eyes Perry, I didn't notice that myself till you pointed it out. Valleyman my thought is to add another layer of firebrick that goes up to the bottom of the pans to keep the flames out of there. Or maybe you could add archboard behind the firebrick to move them closer, which would probably be cheaper and it will retain some extra heat in the arch as well.

[C.Wilcox]

valleyman,

The only problem with leaving the sides of the pan exposed to the flames is that as the sap level drops in the pan the heat on the sides will cause it to burn/scorch leading to a carbon buildup on the insides of your pans. My setup this spring was nearly identical to yours and I did get some pretty good scorching inside my pans. Did it make my pans look terrible? Absolutely. Did it affect the taste of my syrup? Not at all. If you don't mind having some carbon on the inside of your pans then it's not a problem. If you don't want to have to buy new pans again in a couple years I would adjust the brick to keep the fire only on the bottom of the pan.

As for lifting the pans out, I kept a couple of wooden wedges right by the evaporator so when it was time to pull the pan I just drove the wedges under the lip so I could get my fingers under it. Worked good, but watch out when you lift those pans. Mine were the same size and style and I can tell you from experience that they were very unstable when full of boiling hot sugar water. Make sure the kids and pets are somewhere else when you do it.

[valleyman]

3rdgen and CWilcox,

Thanks for the education. I see that Bascom has insulating board for about 9.00 for a 1x3' piece. Seems reasonable enough. My concern is if the insulating board is flat. Part of my plan for this season is to keep the blocks loose (no mortar). One of the Mapletrader folks suggested that in case I want to adjust things around for the following season.

Right now I have everything dry stacked and its pretty stable. I do like the idea of bringing the sides in. I have several 1/2 bricks left over. I'll see how many more I would need to bring in the sides using brick too.

[NedL]

Instead of welding handles. Someone here has suggested just drilign holes in the corners of the lip of the pans using a coat hanger as handles.
Haven't tried it, yet, but will be trying it this year.

[The Back Forty]

I love the pizza oven idea! I can see that in our future. I took up dutch oven cooking already as a partner to syruping.

I have about the same set up with blocks and scorched pan sides. Not a problem for us and for gifts, but wanted to lighten the color a little last year.

What I tried, that worked pretty well, was I took some insulation board and made about a 4.5 inch collar to set the pans in/on. This kept pans above the flames except about 1 inch. I wrapped the board in some galvanized roof edging to protect it and keep dust out of the area. It did keep the pans from scorching and I ended up with much lighter syrup.

It made it easier to grab the pans to lift too. It did slow the boil a little not having those scorching hot sides!

What a great hobby!

[3rdgen.maple]

Valleyman , the archboard is as flat as can be, I used it behind my firebrick on the new arch when I installed it last year. Very very easy stuff to work with. You can cut it with a knife. Lays flat does not need to be glued to the sides I think you will be good using it and still be able to dry stack your brick. You can always just use a little wetter than normal refactory cement as well and still be able to take it apart with relative ease as long as you are sparing with it.

[RileySugarbush]

Don't fret about the hot sides and scorching. I made the tastiest syrup I ever had in a similar setup. The burning darkens the syrup but it filters out clear and tastes great. You can clean them with muriatic acid if you feel the need.

[KenWP]

I had a similar problem with my sink evaporator as the sink was down into the fire about 3 inchs and I had a scorch line around the inside. To loosen it was pretty simple as you just pour sap a little higher in the pan and it looses off and you skim it off with the strainer. Makes great syrup as I have found out. Yet to find anybody who dosn't like mine yet.

[NedL]

I drop my pans in, also. The scorching comes right off with a little soak in a vinegar solution.

[valleyman]

What do you guys think about this idea.

I have a piece of sheetmetal and I was thinking about cutting openings for the pans so the bottoms only would be exposed. I can even line it with arch board or fire brick. If I mortared the half bricks to the sheetmetal, do you think it would to flimsy? Or if I use arch board it will be exposed directly to flame. Will that stuff handle the direct flame?

[PerryW]

I think the sheetmetal is a great idea.

[3rdgen.maple]

I think the heat from on the sheet metal is gonna warp it in a hurry. Yes archboard can take direct flames but any hitting it with wood will destroy it pretty quick. After reading some of the other post i gotta wonder if the current setup is gonna work out fine. Why not do a test boil with water and see if you like it the way it is.

[RileySugarbush]

I bet you will be happy with the sides exposed. It gives you a little more surface area for heat transfer so your rate will be a bit better than if you seal the sides off. Really, I boiled that way for 10 years. Run a little deeper than a flat pan, to keep sap on the sides. I ran as deep as I could without too much splashing. Start out with sap in all. As the front pan boils down, ladle forward and add (trickle from a pot with a valve) to the back.

If you are done for the day you can just shut down and cover. If you want to finish out, , keep working forward until your back pan will be almost empty. Lift it off ( we used fireplace gloves and pliers on opposite corners) and pour it forward, replacing it with a piece of scrap sheet metal to keep the fire in. Repeat as the other pans run low. Finish as far as you dare in the last pan, pour it off and into the kitchen you go!

Next time, just rinse and scrape off the big hunks, more will flake off as you boil and can be skimmed off. Here is my old rig in action:

http://web.mac.com/jabushey/iWeb/Riley%20Retreat/Sugaring%202006.html (http://web.mac.com/jabushey/iWeb/Riley%20Retreat/Sugaring%202006.html)


Think about the past..... The old iron kettle slung over the fire had hot sides! You can claim you are making Heritage Variety Syrup!

[C.Wilcox]

valleyman,

You are going through all the same thoughts and options that I did this spring. In the end I decided it was easier and cheaper and less obsessive to just let the sides of the pans scorch. If need be you can replace them every 2 to 3 years with new pans and call it the cost of business. I can tell you that sheet metal will definitely warp when exposed to that much heat. I used sheet metal to cover the open areas of my "arch" when I removed pans and it warped pretty good. You'd have to support it with some pretty thick metal cross pieces to keep it from buckling. Personally, I think the arch looks great the way it is and it will undoubtedly make you a whole lot of great syrup. I would recommend getting something to lean against the front as a door though. Helps create draft, keeps the heat in, and keeps the kids out.

[valleyman]

CW,
Obsessive you say? I'm finding out that being obsessive is mandatory for maple producers!

I realize I'm going overboard. I ordered the BK150 stove door from Volgelzang 75.00 (includes shipping) Now I have to find a nice piece of 1/4" iron or steel plate and have a local guy torch the opening in it for me.

[PerryW]

You could also sandwich some thin pieces of slate between the top row of bricks and the row below it. Just slide the slate out until it touches the pan and it will keep most of the heat from touching the upper sides of the pan.

[Grizz747]

Last year was my first and made almost 2 gal on the same set up. Great taste. One thing I did was lay a row of block on their sides down the middle from the back to the fire box then ramped on top to the stack. Used a small house fan for a crude forced air. Worked great!

[valleyman]

Hey Grizz

That's good to hear. I'm already thinking about setting it up for some crude forced air too. Thanks for the input. I was thinking of putting a 2-3" duct pipe centered, going from the backside into the fire box. Havent thought to hard in yet. I just got an estimate for a piece of 3/16" x 24"x 24" plate steel for $30-35.00. Thats seems reasonable. As I mentioned earlier in the post, I have a nice door coming so I want to treat it well.

I'm getting close to spending enough so I could have bought a "real" evaporator but its fun improvising.

[RileySugarbush]

I made a front plate/ cast iron door setup like that. It was nice, but there were a few problems:

My block arch was dry fit. I anchored the plate to the front of the blocks with concrete screws and sealed the gap with fiberglass rope. The heat from the fire warped the plate unevenly and pulled the screws out of the block or pulled the blocks around. I just kept stuffing more glass gasket in, having little choice at that point! I recommend you insulate your front plate and door with some ceramic blanket to prevent that. You can just screw it on with stainless fender washers and screws from he inside. That is what I have on my 2x6 now and it holds up pretty well.

I used a cheap electric leaf blower for tremendous combustion. A little noisy bet very effective! I ran it in under the arch slope and into the area under the grates.


Good luck!

[valleyman]

Riley,

That's great advise Thanks!!

[valleyman]

Couldn't help but keep messing with my design. I decided to get the arch ready for forced air should the desire arise. So I proceeded to take down the back side and the raised interior section, turned some block so the open channels in the blocks aligned and then ran some 3" duct through the lower level near the floor so it sits right below the grates. Not sure if I'll use it but the idea of the cheap electric leaf blower got me curious so I want to ready. I'm still waiting for the front door. I'll share some more pics soon.

[darkmachine]

This was our first arch, the design worked, but we ended up widening it above the grates to add fire brick. We dry fit the block and packed them all with sand. The stack sat on the cast end of a barrel stove and we used a piece of sheet metal for the door. The pan we used I don't have a picture of now, it was made out of sheet metal (all one piece, a work of art from the 1920's) with fins, and wooden sides that we had to replace when the pan came to us. We packed the outer 8 inches of each side on the bottom with river clay to prevent the fire from literally burning the sides off our pan. We had a GREAT time, and nothing we encountered detered us from gearing up to make more this season.

907

908

[valleyman]

I just wanted to get another fire stoked to de stress myself and made another pizza. Currently I'm using sheet metal to cover up the openings but I think I'm going to the O&G where I got the firebricks and pick up a couple of large field stone or slate slabs and replace the metal. O&G has a large "leftover" stone pile and You make an offer for what you want. Just keeping busy until sugaring season

[RileySugarbush]

Be careful with big hunks of stone with heat on one side. They can split or crack...sometimes quite violently!


btw: The pizza looks great!

[valleyman]

John,

Maybe it would be better if I can get deal on a pc of 3/16 plate to cover to top instead of the stone. I was thinking that 1-1.5 thick slate or field stone would be able to withstand the heat. I'm planning on getting a pc of plate steel tomorrow for the door opening. That pc is going to run me about $30-35.00. I would need a longer pc for the top.

Your not kidding! I did pop (violently) a slab of cement that was the base for our campfire pit.