Homemade arch question

[relseek]

Hi guys, I just finished my first year at making syrup, I have to tell you i believe I'm hooked. I have been boiling on a cement block arch with a vey old 20"x65" mild steel pan that has been in the family fo several generations I'm told. Well I decided to upgrade and move indoors for next year, I ordered a new 2x5 contiuous flow flat pan from Smoky Lake maple, and was originally going to make an oil tank arch but decided to go a different route. I have attached a pic of my arch in progress and my question is do I need a support(s) going across in the middle of the area that the pan sits on? The first pic is the new arch, the second is what I have been using. 76257626

[psparr]

You won't want the support, it will warp with the heat and your pans won't sit flat. Also be sure to insulate. Same concept. The angle will warp and things get hairy.

[relseek]

I have 1" ceramic blanket and split fire brick to line it with I just dont know if I am going to brick all the way up the ramp or just use the blanket on that part

[psparr]

You shouldn't need brick on the ramp. Only where the wood will hit to protect the blanket. The brick are actually a negative. They hold heat and keep reducing pan level after the fires out. So at the end of your sap when you try to get it as close to syrup in the pan and your level is already low, you don't want any radiant heat getting you too low and scorching the pan.

[relseek]

So there shouldn't be any worry about the pan sagging due to no support?

[lpakiz]

No, no crossmember. Also, you must protect all metal that is exposed to flame, with the exception of the pans, either with insulation, brick, cast refractory or a combination of all of these. Any bare metal that is exposed to flame will deteriorate rapidly, unless cooled by liquid. Including the underside of the top rail, above your top brick.

[relseek]

77757774I figured that I would post some (almost) finished pics of the new arch...I still have to finish putting in the split brick and figure out a blower (AUF) set up. Which brings me to another question has anyone ever tried using a blower that goes in the stack pipe and basically pulls air through the fire?Like this one http://www.amazon.com/Tjernlund-AD-1-Auto-Draft-Stove-Pipe/dp/B003RW7Q82/ref=pd_sxp_grid_pt_1_1#productDetails

[acerrubrum]

i don't think the pan would sag. If it's divided then its got extra support, if not it's still plenty strong. I built my 2x4 arch nearly identical to yours (with no cross support) and I did brick the slope/ramp that goes up from the firebox to the stack vent. I'm glad I did; I now usually have the firebox full of wood, then slide longer pieces of wood over the top of the fire and up the ramp, and resting on the ramp. It really gets the whole pan boiling, and the ramp is full of hot coals during the boil.
I have the blower you linked set up on my boiler. I installed it to control smoke coming out the door during reloading but if I close the door it does get the fire going quickly. I'd imagine it would work the same on an arch so long as the arch is reletively air tight.

[relseek]

Thanks for the responses guys, I have finished putting in the brick and ended up putting brick all the way up the ramp (at least on the floor of the ramp) mainly because i had brick leftover from doing the firebox and I liked your idea of being able to put longer pieces of wood up the ramp without damaging the insulation. I ended up getting a Dayton 227cfm 'high temperature' blower for it. My next questions are Can I mount it directly to the backside of the firebox or should I build some sort of duct work to space it away a little bit. and does it matter how the blower is mounted as far as the outlet being on top or on the bottom (when looking at it from the side)?78017802