Chemical plants often face two enemies at once: aggressive chemicals and serious heat. Many chemical-resistant coatings handle the first and fail at the second. A high temperature chemical resistant coating for process equipment has to hold up against acids, alkalis and salts while the metal underneath runs hot.
Q: What Makes a Coating Both Chemical- and Heat-Resistant?
A: An Inorganic Barrier That Does Not Soften, Burn or Absorb Moisture
Most chemical-resistant coatings are organic: epoxies, polyurethanes and similar resins. They resist many chemicals well, but organic binders have temperature limits. Push past them, and the coating softens, degrades or carbonizes, and the chemical protection goes with it.
Inorganic, glass-based barriers avoid that weakness. A fused glass layer has no organic binder left to burn, and glass is chemically inert to many process chemicals. Incure’s Epo-Weld™ HTSG-791 works this way. It is a single-part silicone-glass coating whose glass frit fuses during a heat cure into a continuous inorganic glass film.
Incure rates HTSG-791 for continuous service up to 1,400°F. After full cure, the catalog lists resistance to humidity, acids, alkalis and salt spray, and describes the glass matrix as chemically inert and non-absorbent to moisture.
Equipment Where HTSG-791 Fits
Incure’s catalog points HTSG-791 at equipment where heat and chemical attack combine:
- Reactor vessels and their external surfaces near heated zones.
- Chemical storage tanks exposed to heat and corrosive vapors.
- Process pipework carrying hot, aggressive media.
- Heat exchanger tube bundles and headers in high-temperature gas streams.
- Exhaust stacks, manifolds and flue gas ducting, where Incure notes protection against sulfur-bearing gas corrosion.
- Boiler casings and outdoor equipment that combine weather exposure with high operating temperatures.
Because HTSG-791 adheres to steel, stainless steel, cast iron, ceramics and porous refractories, one coating can protect mixed-material equipment. Incure also recommends it for sealing porous ceramics, which helps keep corrosive species out of refractory surfaces.
Email Us with the chemicals involved, operating temperature and substrate to confirm whether HTSG-791 fits your equipment.
Qualifying a Coating for Your Chemical Environment
“Acid resistant” and “alkali resistant” describe broad families, not every chemical at every concentration and temperature. Treat qualification as part of specifying the coating:
- List the exposure honestly. Note each chemical, its concentration, phase (liquid, vapor or splash) and the metal temperature at the coated surface.
- Test coupons first. Coat sample panels of the actual substrate, cure them per the schedule and expose them to the real media at temperature.
- Inspect for the right signs. Look for blistering, softening, discoloration or loss of adhesion at edges and scratches, not just overall appearance.
- Plan touch-up access. Coatings fail first at damage points. Decide in advance how a scratched or impacted area will be repaired and re-cured.
Application and Cure
HTSG-791 is applied by brush or spray to a clean, dry surface. Its 400–800 cps viscosity suits brushing complex shapes such as flanges, nozzles and pipe bends. Incure notes that multiple coats can be applied to raise film thickness and coating density, and that matters most for chemical barrier service.
The coating requires a heat cure of 1 hour at 400°F, during which the glass frit fuses. It reaches full oxidation resistance and adhesion on its first excursion to service temperature. Plan how large equipment will reach 400°F, whether by oven, local heaters or a controlled first startup, before you commit to the coating.
When HTSG-791 Is Not the Right Choice
A protective glass coating solves one problem well. It is not a cure-all, and choosing it for the wrong job causes failures.
- Moving or flexing joints. A fused, Shore D70 glass film is rigid. Joints that move with thermal expansion need a flexible sealant instead, such as Incure’s high-temperature silicone sealers.
- Structural repairs. Cracks, holes and failed welds need a filler or bonding compound with real strength, not a coating.
- Service above 1,400°F. Beyond HTSG-791’s rating, look to Incure’s higher-temperature ceramic coatings and adhesives.
- Equipment that cannot reach 400°F. Without its heat cure, the glass frit never fuses. If the part cannot be heated for curing, choose a room-temperature-cure system.
Coating Chemistry Choices in Context
Silicone, ceramic and glass-based coatings each trade temperature, flexibility and adhesion differently, as Incure outlines in ceramic vs silicone high-temperature coatings. Substrate preparation for coatings on cast iron, steel and other metals is covered in how high-temperature coating bonds to cast iron, steel and aluminum. The HTSG product overview explains the fused glass-frit barrier in more detail.
Final Thoughts
A high temperature chemical resistant coating for process equipment has to survive heat without giving up its chemical protection. Incure’s Epo-Weld™ HTSG-791 does it with a fused, inorganic glass film rated to 1,400°F and resistant to acids, alkalis, salts and moisture after cure. Contact Our Team to qualify it for your process.
Visit www.incurelab.com for more information.