Airtight arch

[newmod]

I am in the final construction phase of my 2 x 5 arch for my smoky lake hybrid pan. All of the steel sheeting/panels have been tacked into place ( about every 3 to 4 inches. Did not want to fully weld them in because I am fighting it warping / twisting slightly. Should I use high temp silicone where there could be any air leaks. I am also using 1 inch ceramic insulation all over and firebricking the box. This unit also has AUF and I am afraid that a pressurized fire box will blow out smoke or lose a little heat? Not sure, This is a completely new setup this year and just trying to get everything correct before I fire it up... Thanks
Newmod

[DoubleBrookMaple]

I tack welded like that and used red RTV at all the seams.
I have a blower on mine, and it is tight! Even if I did not, with the insulation it would not come out I think.
Tack Welds

13015

Red RTV

13016

[MunsterMapler]

I just used high temp silicone but like doublebrook said, with the insulation I doubt there will be much air leakng out