Evaporator build question for next year

[Kacey small scale maple]

If I built an evaporator out of a welded angle iron frame for the arch and fire box. Would it be ok to weld like a oil tank gauge metal on to the frame of the evaporator if I lined the whole thing with firebrick and used refractory cement to mortar them together? Would it get to hot? Thanks :confused::confused:

[SmellsLikeSyrupNH]

Is too hot ever really a problem unless you are finishing it up on the evaporator?

Sap will only boil at 212 degrees or so....as long as you keep the pan filled I dont think getting too hot can be an issue. I think those who have blowers on their evaporators prove that out, they want a lot of oxygen getitng ito the fire to get it as hot a possible to remove the water as quickly as they can.

So I think getting too hot shouldnt be an issue.

[Kacey small scale maple]

What about the sides of it with the thin metal

[nymapleguy607]

If you look at the factory built arches the usually something like 18gauge sheet metal. The bends and angles.will give it strengh. If you insulate the metal with fire brick and arch board or blanket it will hold up fine.

[SevenCreeksSap]

My current evap is an oil tank,which is probably 12 ga. thickness and last year just had firebrick on the insides, lining the whole firebox. the firebrick holds the heat so you cant even stand beside it. This year I used 1 in thick, 2400 degree ceramic blanket between the brick and the metal. much higher evaporation rate, better efficiency, the metal still was warm to the touch but you could touch it. I'm thinking of building a better evaporator and will definitely design the ceramic blanket in the whole thing.

[TerryEspo]

I used a pretty thin gauge metal for my three sides of the firebox. Did insulate with ceramic blanket and firebrick, didnt cement bricks, and it works great. Sides are a bit warm/hot, but not hot like a woodstove or warm enough to heat a shack. Sides do not warp at all during a freaking hot boil with blower going.

I do get some warpage on/in the frame as my door gets hard to lock once the unit is hot,hot. All goes back to normal after she cools down.

Next arch will have a stronger frame and same thin metal sides, frame is more important.

Good luck.

Terry