clearance between firbrick and flues

[drpud]

Hi
I'm just in the process of going from a 2 x 4 set up with a flat pan to a 2 X 6 pan with 7" drop flues. I am building the arch myself and in building the arch, is there a specific or ideal clearance one should maintain between the firebrick and the bottom of the the drop flues on the ramp portion of the arch ? Does the ramp on the arch need to be angled or have a pitch or is it sufficient to have it run straight across ?
Thanks
Paul

[Bucket Head]

Without seeing your arch I don't know how your ramp area is. However, whatever the design is, you want your ramp/arch floor/brick to come up to the bottom of the flues- but not touching them. Can you get them up to within a half inch? You want to force as much as, or better yet, all of the fire/heat through the flues. You do that by leaving no"gap" under the flues. This goes for raised flues too. As long as you get your heat going through the flues and not under them, per say, you'll be fine. Look through old posts in the evaporator and homemade sections on here. I'm sure you'll find some pictures showing arch interiors. That will probably give you a better idea on what I'm explaining.

Steve

[maple maniac65]

get the brick as close as possible and then use ceramic blanket to fill the gap under your flues. It is a little bit more of a pain to brush the flues but a blanket will last two years. one year on each side of the blanket.

[drpud]

Thanks guys
I am going to have Reists near Elmira make the pan for me cause I can't TIG weld but was gonna attempt the arch myself based on designs I've seen on this site and on the Trimble 3D website. I just couldn't seem to find info on clearances. I should mention that this will probably be a natural draft arch initially but hope to add blower for AUF in future.
Thanks again
Paul

[maple flats]

Mine is raised flue, but my clearance is about 1/4". You want to force as much of the heat into the flues where they can do the most good.