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u.p. woodfired kiln throat arch repair

updated thu 19 aug 10


gary navarre on tue 17 aug 10

Hey Folks,=3D0A=3D0A After two fairly successful firings of the U.P. Hobaga=
ma a=3D
weak spot in the throat arch started showing up...=3D0A=3D0Ahttp://public.=
fotk=3D t=
his =3D
being the first real arch I've made out of real 1A & 2A bricks there are a =
couple things I think contributed to this starting to collapse. One thing I=
didn't notice while building is the direction of the split firebricks that=
allowed for a seam to crack open at the top of the arch. Also the lagging =
and castable/lag filler did not bond well so the bricks shifted. I decided =
to take things apart ...=3D0A=3D0A
kl3/throat-arch-repair-jpg.html (click next for five more shots)=3D0A=3D0A=
... =3D
and practice a bit of kiln repair. =3D0A=3D0A I guess I see two options so =
Both fixes will include turning the two chamber wall bricks at the top of =
the arch 90=3DB0 and hopefully stop a crack from developing when the arch i=
s =3D
back in place. The resetting of the arch bricks is a bit touchy because the=
gaps don't quite match up if I use them all and I'll need to fill in about=
a 3/4" gap with a pumpable refractory mortar or castable/lag mix. On the o=
ther hand I could eliminate one arch brick and fill with straight castable =
as the keystone. I still have a 50# sack of Hi-Cast and I've never tried to=
cast in place a "monolithic" so what ta heck eh? let's have a go. That is =
what the stuff is designed for ain't it. I'm starting to think I've been a =
little to chintzy and got to thinking like a poverty potter again by mixing=
lag in with the castable to stretch it out, geeze it's only about a buck a=
pound. I've used only one sack so far and it is good I ordered an extra wh=
en I did or I might have to wait to
get more. Has anyone else tried using castable to make something the size =
of a brick and had it survive repeated harsh firings? =3D0A=3D0A Guess that=
's i=3D
t so stay in there eh.=3D0A =3D0AGary Navarre=3D0ANavarre Pottery=3D0ANavar=
re Enter=3D
prises=3D0ANorway, Michigan, USA=3D0A