Does anyone have experience with the durability of stainless steel
hardware in a wood stove firebox? Google shows conflicting claims from
various manufacturers. I disassembled the stove this weekend and plan
to reassemble it with hardware-store stainless steel bolts, as some of
the originals have thinned down after about 30 years.

The fully assembled stove is locked together horizontally by tongue
and groove joints between the panels. These bolts keep the plates in
place if the stove tips or is moved, so they aren't tight and I don't
think the higher thermal expansion of ss will cause problems. The
other load-bearing bolts will stay mild steel.

Jim Wilkins

Jim Wilkins fired this volley in news:5e7af89e-
:

Does anyone have experience with the durability of stainless steel
hardware in a wood stove firebox? Google shows conflicting claims
from
various manufacturers.

The problem is that most corrosion-resistant steels lose much of that
property at the heat encountered there.

The only solution to it is to protect the steel parts from the heat
with a refractory brick (or panel) liner. If your stove never had a
liner, it's tough to add one that's thick enough to do the job, and
still not rob too much volume from the box.

Still, I'd rather have SS fasteners than merchant stock steel. At
least there's the chance they won't be a solid lump by the time I must
get them back out.

LLoyd

I guarantee that you'll hate yourself in the morning if you use SS bolts
there. They GALL!!!!!!!!!!!
Maybe use plain steel nuts with them. We have used SS bolts and nuts
in the past in non-heted outdoor projects with really poor results. We
put up on railing using some really pricey Allen head SS screws and SS
nuts and had to take it down just a few months later because the color
didn't match (that's another story). About half the fasteners galled
so badly that they had to be ground off. When we went out and
researched the problem, we got plenty of input from people saying,
(essentially) "you dumbies, everybody knows that won't work!". Now,
when we do use them, we coat the threads with Never Seize, the type with
nickel, and that seems to work okay. But even then, it's hard to use
because it gets all over everything if you aren't careful. I don't know
if Never Seize can handle heat,though, so I wouldn't recommend it for
your application unless you can get assurances that it will work there.

Someone did speculate the if you use a stainless steel of one type for
the bolt and another type for the nut, that the problem goes away. I'd
research that issue if you really want SS in there.

I always thought that coarse thread screws and square nuts were just
the ticket for wood stoves. Don't they call 10-24 bolts "stove bolts"
just for that reason? They come apart pretty well and aren't too hard
to break off it needed. 30 years ain't to bad for the originals.
As blacksmiths, we are often faced with forge repair. We almost
always use plain steel fasteners in the forges. If nothing else, a
quick burst from the old "gas axe" and the offending fastner is gone.

Pete Stanaitis
---------------------------


Jim Wilkins wrote:

Does anyone have experience with the durability of stainless steel
hardware in a wood stove firebox? Google shows conflicting claims from
various manufacturers. I disassembled the stove this weekend and plan
to reassemble it with hardware-store stainless steel bolts, as some of
the originals have thinned down after about 30 years.

The fully assembled stove is locked together horizontally by tongue
and groove joints between the panels. These bolts keep the plates in
place if the stove tips or is moved, so they aren't tight and I don't
think the higher thermal expansion of ss will cause problems. The
other load-bearing bolts will stay mild steel.

Jim Wilkins

On Sep 22, 8:13 am, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:
Jim Wilkins fired this volley

Does anyone have experience with the durability of stainless steel
hardware in a wood stove firebox?

The problem is that most corrosion-resistant steels lose much of that
property at the heat encountered there.

The only solution to it is to protect the steel parts from the heat
with a refractory brick (or panel) liner. If your stove never had a
liner, it's tough to add one that's thick enough to do the job, and
still not rob too much volume from the box.

Still, I'd rather have SS fasteners than merchant stock steel. At
least there's the chance they won't be a solid lump by the time I must
get them back out.

LLoyd

I just answered my own question with a magnet. The ones I replaced
about 10 years ago -are- stainless and they are in very good condition
after wire-brushing the crud off. The threads and the lettering on the
heads are still crisp and the nuts turn freely. These are exposed to
the flame at the top sides of the main firebox where they attach the
upper smoke box. The lower ones that hold the sides to the base are
original, were installed with NeverSeize in 1985, and came out easily
although the exposed part was seriously eroded, more so in the cooler
back end of the firebox.

Except for one hanging baffle the cast iron is in fine shape. I think
it's a Scandia ripoff of a Jotul 118 from the 70's. The castings are
marked Taiwan, the hardware is 1/4-20 with 10mm hex heads.

This is the stove I anneal and heat-treat in. A piece of steel coated
in Ivory soap and left in overnight cleans up to a smooth grey with
little or no scale. I modified the stove by drilling some small holes
to let more secondary heated air into the upper smoke box and close
down the main air intake until the flame shows some violet. At this
setting it burns about 7-8 Lbs of wood per hour with no visible smoke.
Below this rate it won't maintain a stable fire.

Jotul claims their original will burn all night "cigarette" style from
front to rear but I have never been able to make this work without a
lot of smoke. I arrange the fire muffle style with an air passage
between the logs down the center and get a maximum of 2 hours of good
heat.

Jim Wilkins

Jim Wilkins wrote:
On Sep 22, 8:13 am, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:
Jim Wilkins fired this volley

Does anyone have experience with the durability of stainless steel
hardware in a wood stove firebox?

The problem is that most corrosion-resistant steels lose much of that
property at the heat encountered there.

The only solution to it is to protect the steel parts from the heat
with a refractory brick (or panel) liner. If your stove never had a
liner, it's tough to add one that's thick enough to do the job, and
still not rob too much volume from the box.

Still, I'd rather have SS fasteners than merchant stock steel. At
least there's the chance they won't be a solid lump by the time I must
get them back out.

LLoyd

I just answered my own question with a magnet. The ones I replaced
about 10 years ago -are- stainless and they are in very good condition
after wire-brushing the crud off. The threads and the lettering on the
heads are still crisp and the nuts turn freely. These are exposed to
the flame at the top sides of the main firebox where they attach the
upper smoke box. The lower ones that hold the sides to the base are
original, were installed with NeverSeize in 1985, and came out easily
although the exposed part was seriously eroded, more so in the cooler
back end of the firebox.

Except for one hanging baffle the cast iron is in fine shape. I think
it's a Scandia ripoff of a Jotul 118 from the 70's. The castings are
marked Taiwan, the hardware is 1/4-20 with 10mm hex heads.

This is the stove I anneal and heat-treat in. A piece of steel coated
in Ivory soap and left in overnight cleans up to a smooth grey with
little or no scale. I modified the stove by drilling some small holes

What's this soap process?

On Sep 22, 10:48*am, Cydrome Leader wrote:
Jim Wilkins wrote:

This is the stove I anneal and heat-treat in. A piece of steel coated
in Ivory soap and left in overnight cleans up to a smooth grey with
little or no scale. I modified the stove by drilling some small holes

What's this soap process?

Ivory or other sodium stearate soap bakes into a coating that protects
hot steel to some extent. Another old formula I haven't tried is salt
and flour.

Rub the moistened soap on tool steel before hardening it. As long as
the part stays in a reducing flame the cutting edges don't degrade
quickly at red heat, or scale in the air between the fire and the
quenching bath. If I do it right I can sharpen the edges with a Dremel
or hand whetstone rather than having to set them up on the surface
grinder.

I harden small tools with a propane torch angled into a tin can with
some charcoal in it, which contributes enough radiant heat of its own
that the propane flame can get the steel up to hardening heat. When
the steel doesn't attract a weak magnet I dump everything into a pail
of water. The instructions for oil-hardening steel say that water is
OK for small cross-sections.

Do this in a safe place outdoors and don't use a magnet strong enough
to lift the part.

"Jim Wilkins" wrote: (clip) When
the steel doesn't attract a weak magnet I dump everything into a pail
of water. (clip) don't use a magnet strong enough
to lift the part.
^^^^^^^^^^^^^^^^^^^
A jeweler once told me he does something like this to heat treat hair
springs. He holds the spring over a quenching bath with a magnet, and then
plays a torch on it until it drops off into the bath. Of course, his magnet
is strong enough to lift the part.

"Leo Lichtman" wrote in message
...

"Jim Wilkins" wrote: (clip) When
the steel doesn't attract a weak magnet I dump everything into a pail
of water. (clip) don't use a magnet strong enough
to lift the part.
^^^^^^^^^^^^^^^^^^^
A jeweler once told me he does something like this to heat treat hair
springs. He holds the spring over a quenching bath with a magnet, and
then plays a torch on it until it drops off into the bath. Of course, his
magnet is strong enough to lift the part.

Just be aware that for some steels, mostly of the high-alloy types IIRC, the
critical temperature, at which the phase change is securely accomplished and
the steel is ready for quenching, can occur at a slightly higher temperature
than the Curie point, which is where ferromagnetism disappears.

In other words, for reliable hardening, give it the Curie point plus a very
slight bump. This shouldn't be an issue with plain carbon steel.

--
Ed Huntress

Jim Wilkins wrote:
On Sep 22, 10:48?am, Cydrome Leader wrote:
Jim Wilkins wrote:

This is the stove I anneal and heat-treat in. A piece of steel coated
in Ivory soap and left in overnight cleans up to a smooth grey with
little or no scale. I modified the stove by drilling some small holes

What's this soap process?

Ivory or other sodium stearate soap bakes into a coating that protects
hot steel to some extent. Another old formula I haven't tried is salt
and flour.

Interesting.

I've coated steel parts in ivory to keep them from rusting and didn't want
them oily. The metal darkens a bit, like well handled tool, but doens't
rust orange at all.