Mild Steel vs. Stainless-Steel
Noonan's Welding and Heating began manufacturing Northland Outdoor Wood Furnace in 1991 using heavy gauge A-36 mild steel in the furnace for the firebox and water jacket construction. This choice of steel and other fine features have made our furnaces very efficient, corrosion resistant, and reliable.
Other manufacturers have been using stainless-steel in some or all of their
models because of an unacceptable amount of failures to their furnaces due to
corrosion and other reasons.
Many of these corrosion problems occur because of their furnace design. Furnaces
with chimneys exiting out the top allow creosote to run back into the firebox.
This, mixed with ashes, is highly corrosive. Creosote also runs down the side
of the chimney causing damage to the outside of the furnace and sometimes results
in damage to the water jacket beneath. Our chimney exits out the back of the
furnace eliminating these problems. Also, some of their firebox designs are
difficult to clean, leaving unwanted ash buildups which leads to corrosion.
Our fireboxes are round and very easy to remove all ashes. Our water jackets
also incorporate 2" drain plugs on the bottom front and bottom back for
100 percent cleaning. Debris buildup on the bottom of the water jacket is the
main culprit for water jacket failure. Other manufacturers do not offer this
dual clean out feature to prevent this.
Stainless-steel does have a good reputation for corrosion resistance especially
items made from it that we use around the home that we are familiar with. Most
people assume, because of this, that all stainless steels are the same but they
are not. Some manufacturers of stainless-steel outdoor wood furnaces, claim
through their own research, that the type of stainless they use is best suited
for this application. Then why are these same manufacturers using several different
types of stainless among them? Stainless-steel types are made for specific applications.
You would think there would be one type of stainless-steel specifically suited
for outdoor wood furnaces. Because of this and with insufficient long-term research
and testing, stainless steel used in outdoor wood furnaces, in our opinion,
remains new and unproven in many aspects.
Here is some information and facts about stainless-steel you should consider:
No. 1) Stainless is not 100% corrosion proof. Don't be misled. Some stainless
steels offer more corrosion resistance than others.
No. 2) Stainless is a very poor heat conductor. It does not transfer heat as
well as mild steel resulting in using more wood.
No. 3) After years of heating and cooling, which causes expansion and contraction,
stainless steel has a tendency, under certain circumstances, to crack or tear
and become brittle. This problem is made even worse because the thickness of
stainless-steel used in these furnaces is usually twice as thin as what is used
in mild steel furnaces. Type of stainless steel used is also a major factor.
No. 4) Most manufacturers have not had a stainless-steel furnace on the market
long enough to say it will last longer than a properly maintained high-quality
mild steel furnace.
No. 5) The cost? Much higher. For example: The money you would save by purchasing
a mild steel furnace would pay for some or all of your installation costs or
several years supply of firewood.
No. 6) Warranty coverage. Most stainless-steel furnace manufacturers offer
a limited warranty, which is pro-rated and is basically the same warranty as
offered on mild steel furnaces. If stainless steel is so reliable and maintenance
free, why don't these same manufacturers offer a unlimited warranty which would
cover 100% of all warranty repairs in this time frame such as corrosion, workmanship,
parts, labor, shipping and freight? The customer, in most cases, will pay some
or all of these repair costs under this warranty.
No. 7) Repairs needed to firebox and water jacket after warranty expires. This
will be expensive. It requires special equipment, materials, and expertise in
repairing stainless. Not everyone, except the manufacturer or an equivalent
in this field, is qualified to do these repairs. Mild steel repair does not
present these problems since it is more widely used and repair service is more
readily available and reasonable.
Buying and installing an outdoor wood furnace is an investment. Know what you're
buying! We're confident that we have a furnace to suit your needs at Northland
Outdoor Wood Furnaces.