Homemade Evaporator Questions

[Amber Gold]

I just found this forum last week and wanted to say thanks for all of the great information.

This saturday I'm going to be constructing a new evaporator out of concrete block so that it'll be ready for Sunday's boil. I have some questions on evaporator construction for the experts.

1. Can I use regular red brick to line my firebox or does it need to be fire brick?

2. I have a 2'x2' pan and the firebox will be sized appropriately. I was going to put sand in the back of the fire box to mimic the real evaporators. Is this worthwhile doing?

3. I am going to 90 my smokestack out the back of my firebox, just below the bottom of my pan. Should I use 6" or 8" pipe? I wasn't sure with the size of my fire if I'd get enough draw off the 8" pipe, then again I don't want it to be undersized either.

4. If I can figure out a way to support the smoke stack, should it exit the the fire box vertically directly behing my pan?

4. Can fiberglass insulation, minus the paper facing, be used to seal leaks and around the hole for the smokestack. Also to rest my pan on so that it forms a when it rests on teh concret block. If not fiberglass insulation what can I use?

Everything is going to be dry set this year because I'll be moving it once the snow melts. I also have some sketches that I can PDF if anyone's interested.

Thanks in advance for your help.

[Sugar Daddy]

Good to see another back yard sugarer!

My set-up is similar to what you've described. Pan is about 2' x 4', set on concrete blocks that are filled with sand. It's served me well for the past 5 years, but after this year it will need rebuilding as some of the blocks are cracked. To answer your questions directly:

1. Red brick will crack and break up. If you're going to line the fire box, use fire brick.

2. Given the size of your pan, and consequently the firebox, there won't be much room for filling the back with sand. But it's worth it on larger fireboxes.

3. I've got a 6" diameter stack, 4' long and it provides good draft.

4. My stack is supported with 3 wires that are tied off to near-by trees. You could also drive a couple of steel fence posts into the ground on either side of the stack and tie it off to those supports. As for exiting the firebox, I use a heating duct adapter that is essentially a 90 degree elbow - 6" round on one end and about 6" x 8" rectangular on the other. It fits very nicely in an opening between the blocks.

5. Don't know if fiberglass insulation will stand up to the heat. I use the gasket material for wood stove doors for sealing around the stack outlet.

As long it gets sap boiling it should work. Good luck!!

[Amber Gold]

Thanks for the tips.

What do you use for a door?

I've got a lousy weekend ahead of me. I just checked the weather and it says 3" of rain starting tonight and ending Sunday afternoon.

[Sugar Daddy]

Yeah, I see that there's nearly every type of watch/warning posted for the Northeast. Below zero here tonight with moderating temps forecast afterwards, so I'm planning to tap Sunday or Monday.

My "door" is 2 concrete patio blocks that lean against an opening in the firebox that has roughly the same dimensions. The amount of draft is determined by the angle by which the patio blocks are leaning against the opening.

The door opening in the firebox is 2 blocks high by 1 block wide, with a course of block above. The block above is supported by a 2 patio blocks - one on each side of the door opening, which are set upright on edge.

Here's a photo of my set-up from a couple of years ago. You might be able to get an idea of how the door is configured from it.

[lpakiz]

Hi,
I sealed around my pan with sand and 5% salt mix (the same we use on the road for ice conditions.) Make it almost soupy wet with water and trowel it on. Also seal around the bottom of the pan. About an hour of heat and it is hard as concrete.
I tried building fiberglass to insulate the outside of my I-beam arch. It will almost last the season but it is a lot cooler there than around the stove pipe and the pan, so I am quite sure it would burn out within several hours.

[TapME]

I use fiberglass insulation to seal the cracks and it works. The tighter it is the longer it last. This year I am using drop ceiling insulated panels without the plastic to make gaskets for the pans. It is compact and will be cut into 1 1/2'' strips and used with a little gasket cement, should work fine and last the season, and cheep.

[Amber Gold]

Thanks guys. I'm going to build it today and boil tomorrow. I'll take some pics and let you all know how it works. I was just digging around in my garage and came across 8-10 feet of 6" HVAC pipe, so that will save me on that expense.

[Mac_Muz]

Sugar Daddy OT: In your picture is a birch tree. On that tree is a dark object. I can't tell if that is something you put there, or something that grew there.

Also in the fore ground there seems to be a big hunk of that same fungus, if it is...

Is it? Is that burnt looking fungas common there? I am into woodland living skills, and that stuff is a good spark catcher for flint and steel when dried.

Perhaps you might want it, and or perhaps you would be willing to send me some for shipping and what ever troubles it is worth to you do so...

I find it in NH, but it isn't common.

When I find items like I think that is, I collect them and give them to my friends when at Voo.

[Amber Gold]

I setup my rig as you described and it worked great. I did a test fire Saturday night and I had my stack glowing cherry red and it must've been a three foot flame out the top of it! Pretty cool. The 12x6 90 degree register adapter worked great.

I was getting about 3-4 gph without preheating my sap and that was with very windy conditions. I'm thinking of making some minor modifications that I think will improve it. I found that by just loading under the front of the pan with wood I would get a more even boil across the pan so I'm going to pile sand in the back to creat an arch. I also think I'm going to buy a straight 12x6 register adapter and have it vent vertically directly behind pan. I think this might help with keeping more of the flame in contact with the pan. I put fiberglass around the register to try and seal it, but it didn't last very long. It seemed to run fine without it so I guess I really didn't need it.

I was going to post some pictures, but couldn't figure out how.

A friend just offered me a 2'x6' arch for $100. It needs to be cleaned up and a sheet of tin replaced, but otherwise it's all there. I already have a 2' syrup pan so the only thing else I need is a flue pan and a lot more buckets or tubing. I already can't wait for next season!

Thanks for your help.

[NedL]

Hi All,

When setting up my block evaporator, I got alot of great advice here. I had my first big boil this past weekend. I boiled down 80 gallons of sap to about 4 gallons in 7 hours. Finished that down to a little over 2 gallons of yummy sweet stuff inside. My set up is with 3 steam pans dropped into the evaporator. Very happy with the results so far. Looks like a big sap week. I got 15 gallons from 13 taps yesterday and I have 2 more milk jugs waiting to be set up on taps.