Evaporator warping

[gmc8757]

Hey Guys...first year boiling in my new 2x4 evaporator. I firebricked it according to the plans and have arch paper installed. I burn small split real dry pine or left over lumber cut real small with a blower. Stack temps were from 900-1100. I noticed the sides of my firebox are warping inward pretty good. Not sure what to make of it. Has anyone else seen this? Is that too high of a stack temp?

[VTmaplehobby]

Yup, almost the same exact scenario as yours. Noticed a spark come out from under the pan, thought it was the gasket at first, then realised it came out under the rail. Our stack temps are in the 700-800 range. Just gonna finish the season pull the pan and clamp it back into shape and weld it up.

[gmc8757]

No kidding, same thing. Was this your first year with this arch? I was really hoping to meet it in good shape and take care of it. Now these bows in it will annoy me forever.
Your stack temps are lower than what I'm getting up to. Should I lower mine?

I've seen on here ppl mention meltdowns. What temps do they occur?

[Urban Sugarmaker]

I haven't really noticed the warping. Maybe a little inward warping along the sides of the firebox but not enough to concern me. I used the arch board on the sides and front and back ends. I also have a double layer of brick on the sides of the fire box. I do know that the fire box temperatures are extremely hot with the blower running. For next year I will probably add a second layer of brick to the back section behind the fire box.

[FordHeritageFarm]

When I added the blower to my setup this year I noticed sparks and smoke and ash coming from various locations. Between pan and gasket, I added another layer of gasket and that forgave any warpage. Under the rail on the outside, I stuffed some gasket all along the length of each side up under the rail. I added a piece of gasket upright to the top front of the arch and pulled the pan against it. This held in a lot, but I had already noticed arch warpage. Will also be planning on re-bricking next year. Not sure of stack temp. I run a Mason 2x4 XL and have been running it around the clock since Monday morning.

[VTmaplehobby]

There is a small gap where we didn't brick directly under the pan about 3/4 of an inch. I assumed that was the cause of the warp. I guess insulation is a good idea. We don't run the blower at all, we just left the open 2" pipe adapter in the back of the ash compartment and leave the ash door open. When we open the door to fire she will shoot a 3' torch out of the 11' tall 6" stack. I think we are getting plenty of air. :)

[gmc8757]

Definitely not because of the 2 inch gap. I have arch paper around the whole thing, and then fire brick, and then refractory cement. Didn't miss an inch.

[Urban Sugarmaker]

Definitely not because of the 2 inch gap. I have arch paper around the whole thing, and then fire brick, and then refractory cement. Didn't miss an inch.

Did you receive arch paper for the floors of the arch? I did not. Only the sides, front, and back.

[gmc8757]

Sorry, no, not the floors. only the sides.
I doubled up on the brick for the floors.

[Urban Sugarmaker]

Sorry, no, not the floors. only the sides.
I doubled up on the brick for the floors.

I put full brick on the fire box floor and half brick on the back floor. I am going to add a second layer to the back. Any way you can post a picture of the warping? I was looking at mine yesterday, but I'm not really seeing a problem. Thanks.

[gmc8757]

11678
It's easier and more obvious in person.
Maybe it's nothing to be concerned about..who knows

[Urban Sugarmaker]

Mine has the same curve, although maybe not as pronounced, it's noticeable. I don't think it's a big deal as long as the rails are straight. It looks like they are.