Silicon carbide (SiC) heating elements are the workhorse of industrial high-temperature furnaces up to roughly…
Burnout Furnace Heating Elements: What You Need to Know
What a burnout furnace does
A burnout (or dewaxing) furnace slowly drives wax, binders and organics out of investment castings and dental moulds before firing. The profile is the hard part for an element: a long, low-temperature soak (often 200–700°C for many hours) followed by a ramp. That low-temperature dwell is precisely where MoSi2 is weakest.
Element choice for burnout
| Profile | Recommended element | Why |
|---|---|---|
| Long soak 200–700°C | SiC | No pesting risk; stable through long low-temp dwells |
| Peak above 1000°C, short low-temp | EQ1700 MoSi2 | Cleaner for the firing stage if low-temp dwell is brief |
Why SiC usually wins here
MoSi2 suffers destructive oxidation in the 400–700°C range — the pesting window described in low-temperature oxidation. Because burnout furnaces live in that window for hours, SiC is the safer, longer-lived choice for most wax and binder removal. When the same furnace also fires dental zirconia at 1450–1550°C, a separate MoSi2 stage or a dual-spec design is worth discussing with us.
Extending SiC life in burnout
SiC ages as its resistance rises, so size generously and plan for a gradual power increase over life. Practical steps are in extending SiC life, and the full element range is the SiC guide.
Sizing
Work from the chamber kW and the surface-load ceiling, then confirm the count with the element quantity calculator (the principles apply to SiC too). For the dental firing stage specifically, see choosing a dental element.
Summary
For burnout furnaces, SiC is normally the right element because of the long low-temperature soak that destroys MoSi2. Reserve MoSi2 for short-low-temp, high-peak duty or a dedicated firing stage. Keep SiC surface load inside rating and plan for resistance ageing. Full data in the SiC guide.
Re-elementing a burnout furnace? Browse SiC elements in stock, or send us your profile and chamber size for a free layout.
Why specify with HeatingDriver
Why specify with HeatingDriver — HeatingDriver is a manufacturer and exporter of MoSi2 (molybdenum disilicide) heating elements with nearly 20 years of experience. We supply EQ1700U / EQ1800U / EQ1850U grades for 1700–1850°C, free drawing review, custom sizes and shapes, and technical support for furnace builders worldwide. Browse our MoSi2 heating elements.
What are burnout furnace heating elements?
Burnout (wax/resin removal) furnaces use MoSi2 elements to raise the chamber through the binder-removal temperature range in an oxidising atmosphere.
Which MoSi2 grade suits a burnout furnace?
Most burnout cycles stay below 1700°C, so EQ1700U is typical, with EQ1800U if higher temperature is needed.
Why MoSi2 for burnout?
MoSi2 gives clean, controllable heat and a self-healing protective layer in air, handling the off-gassing of binder removal.
What surface load applies?
Burnout furnaces are designed around 4–9 W/cm² MoSi2 surface load with good airflow.
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