Heat-treatment fixtures, jigs and furnace parts scale and oxidise because they go through repeated high-temperature cycles in air with no protective layer. A ceramic protective coating on the fixture helps reduce that. Micron 2131 Ceramic Powder Coating Spray lays down an even ceramic powder coat with a fast-evaporating solvent, and its page lists protective coatings on fixtures and tooling in heat-treatment operations. If you need a brush-on coating with a published temperature rating, Micron 2138 CeraCoat Z states up to 900°C in air.
Why it happens
- Repeated high-temperature exposure in air. Every cycle oxidises the fixture surface a little more, and the oxide flakes off as scale.
- No protective coating. Bare fixtures take the full effect of heat and atmosphere.
You will see scale building up on fixtures, and fixtures wearing and contaminating parts over repeated thermal cycles.
How to fix it
- Aerosol ceramic coating on fixtures, jigs and furnace parts: Micron 2131 Ceramic Powder Coating Spray. Its page says ceramic protective sprays can be applied on fixtures, jigs and furnace parts to reduce wear and contamination during repeated thermal cycles, and describes use in heat-treatment operations to protect tooling, fixtures and equipment surfaces from oxidation and scaling.
- Brush-on coating with a documented temperature rating: Micron 2138 CeraCoat Z, a water-based boron nitride coating. Its page lists heat-treatment fixtures and states up to 900°C in air and up to 1400°C in vacuum.
The 2131 page has no step-by-step directions and no temperature limit. Follow the instructions on the can and the TDS, and ask Micron for the temperature rating before relying on it. For 2138, follow its page: the substrate must be clean, dry and free from oil, grease, rust, dust, paint or lacquer residues; stir before use; apply by brush, roller or suitable spray system; let it dry.
In both cases, start from a clean fixture. Coating over loose scale gives the new layer nothing sound to sit on.
What to avoid
- No temperature limit is published for 2131. Do not quote one, and do not assume it covers your furnace temperature.
- 2131 contains a fast-evaporating solvent. Apply it only to cold fixtures, away from furnaces and flames, and let it flash off fully before heating. Treat it as flammable until the SDS says otherwise, and use ventilation.
- Do not exceed the stated 2138 limits: 900°C in air, 1400°C in vacuum.
- Do not apply 2138 over oil, grease, rust or old paint.
When to ask an expert
Ask Micron technical if:
- you need a specific temperature rating for 2131;
- the furnace uses a controlled atmosphere (vacuum, nitrogen, endothermic gas);
- fixture distortion or cracking, not just scaling, is the problem.
Distortion and cracking are fixture design and material questions for your heat-treatment engineer.
FAQ
What temperature can 2131 take?
Micron's page does not give a figure. Ask Micron before using it at your furnace temperature. If you need a published rating, 2138 states up to 900°C in air.
Spray or brush-on: which should I choose?
2131 is an aerosol for quick coverage. 2138 is a water-based coating applied by brush, roller or spray system, with stated temperature limits.
Do I need to remove old scale first?
Yes. Both products need a clean surface. The 2138 page is explicit: clean, dry and free from oil, grease, rust, dust, paint or lacquer residues.
Can I spray 2131 on a warm fixture?
No. Apply it to cold fixtures only, away from furnaces, and let the solvent flash off fully before heating.
See the product: Micron 2131 Ceramic Powder Coating Spray. Related: 2138 CeraCoat Z. More welding and fabrication fixes: welding hub.