bricking new set up

[mike z]

We've been building a new evaporator, and it's almost complete. The style is similar to those being currently sold, having built it around a Maple Pro arch front we got few months ago. My question is - I have 5.5" of space in the back portion of the of the arch, (under the back pan) I have 3/4" ceramic blanket that I plan to put down, but what thickness firebrick should I go with? If I use 2.5", assuming the blanket will compress some, I will only have about a 2.5" air space. Is this too little? I could go with 1 1/4" brick? The arch is 2x10 with divided flat pans, not fluted, and a 9" stack. Thanks

[maple flats]

under the back pan you only want about 1/2" so the hean gets forced up into the flues. If this is a flat pan you might want about 1.5" clearance or something like that. On my raised flue I have vermiculite poured in the back up to the desired height, then I laid firebrick dry on top to be almost level with the side rails of the arch AFTER adding about 1/4-3/8" of dry refractory that I just sprayed lightly with water using a spray bottle. It hardened well and keeps any vermiculite that ended up in between the bricks from flying up the stack. Basically the space I have is only about 1/4" plus the thickness of my pan gasket (about 3/8" compressed)

[vtjeeper]

We've been building a new evaporator, and it's almost complete. The style is similar to those being currently sold, having built it around a Maple Pro arch front we got few months ago. My question is - I have 5.5" of space in the back portion of the of the arch, (under the back pan) I have 3/4" ceramic blanket that I plan to put down, but what thickness firebrick should I go with? If I use 2.5", assuming the blanket will compress some, I will only have about a 2.5" air space. Is this too little? I could go with 1 1/4" brick? The arch is 2x10 with divided flat pans, not fluted, and a 9" stack. Thanks

you say it's a flat pan so you will need a little more room than somebody with a flu pan that needs their heat to go up into the flues. I used a small bros 2x6 flat pan this year on cement blocks with a piece of metal roofing bent over to form the bottom of the arch and force the heat.I have read and now experienced that the space at the back should be somewhere around the same as the area of your stack area. like you said a 9 inch stack(I used 8) so area of a circle(pi*r*r) 3.14*4.5*4.5=63.5 square inches. 63.5/24inch wide arch=2.65 inches high. if it's not quite 24 inches wide then do the math. thin brick would give you 78 square inches of space but the way. I have around 2 inches of space at the back of mine but tried putting a piece of 1" square tubing across the back once this year and it didn't work for crap, pulled that out and it was back to boiling the whole pan nice. with a good fire it will pull the flame all the way back to the stack, my stack is 14 feet I think. I'm hoping to find the time to build an arch for next year out of steel. good luck