During the ceramic restoration process, using a hot air blower to heat the ceramic pieces is a highly cautious technical operation, mainly used to soften the restoration glue, adjust the position of the ceramic pieces or promote adhesion. The following are the key precautions and operational points during the heating process:
First, preparation of equipment and materials
Selection of hot air blower
Temperature adjustability: Prioritize the selection of hot air blowers with a wide temperature range (50℃ to 600℃) and precise adjustment to prevent ceramic cracking or carbonization of repair glue due to excessively high temperatures.
Wind speed control: It should have multiple wind speed adjustment functions. A low wind speed is suitable for fine repair, while a high wind speed is used for large-scale rapid heating.
Fix the compatibility of the glue
High-temperature resistant adhesive: Choose epoxy resin adhesive or ceramic-specific adhesive that can withstand temperatures above 150℃ to ensure that the adhesive does not fail during the heating process.
Curing temperature matching: The optimal curing temperature of the glue should match the heating temperature of the hot air blower (for example, the curing temperature of epoxy resin glue is usually 80℃ to 120℃).
Auxiliary tools
Infrared thermometer: Real-time monitoring of the surface temperature of ceramics to prevent local overheating.
Heat-insulating gloves and clamps: Prevent high-temperature burns and safely secure ceramic pieces.
Second, key points of heating operation
Temperature and time control
Staged heating
Preheating stage: Heat at a low temperature of 80℃ to 100℃ for 1 to 2 minutes to allow the ceramic and glue to heat up slowly and reduce thermal stress.
Curing stage: According to the requirements of the glue, raise the temperature to 120℃ to 150℃ and continue heating for 3 to 5 minutes to ensure the glue is completely cured.
Avoid overheating: Ceramics have poor thermal shock resistance. Temperatures exceeding 600℃ may cause crack propagation or structural damage.
2. Heating method and distance
Uniform heating
Swing heating method: Keep the nozzle of the hot air blower 15 to 20cm away from the ceramic plate and move it slowly in an “S” shape to avoid heat concentration.
Back heating: For double-sided repaired ceramic tiles, prioritize heating the back to reduce the risk of thermal damage to the front decorative layer.
Local heating techniques:
Use aluminum foil or high-temperature resistant insulation boards to cover the non-heated areas and concentrate the heat on the damaged parts.
3. Real-time monitoring and adjustment
Temperature monitoring: Use an infrared thermometer to measure the surface temperature of the ceramic every 30 seconds to ensure uniform temperature without exceeding the limit.
Observe the state of the glue: Stop heating immediately when the glue changes from transparent to slightly yellow or stops flowing after curing.
Third, safety and risk control
Personal protection
Wear high-temperature resistant gloves, goggles and dust masks to prevent scalding from high temperatures or inhaling ceramic dust.
Environmental safety
Operate on a fireproof and explosion-proof workbench, keep away from flammable materials, and be equipped with fire extinguishers.
Emergency response
Ceramic cracking: Immediately stop heating, temporarily fix the crack with low-temperature glue, and reevaluate the repair plan after cooling.
Glue carbonization: Remove the ineffective glue, reapply high-temperature resistant glue and adjust the heating parameters.
Fourth, reference for repair cases
Case 1: Repair of cracks in Antique Porcelain
Step:
Fill the cracks with low-viscosity epoxy resin adhesive and smooth the surface.
Set the temperature of the hot air blower to 100℃, hold it 20cm away from the porcelain, and heat it in an “S” -shaped trajectory for 3 minutes.
Wrap the porcelain with cotton cloth and let it cool naturally to room temperature.
Effect: Cracks are completely filled, the bonding strength reaches 85% of the original porcelain, and there is no discoloration on the surface.
Case 2: Ceramic ornament breaks and adheres
Step:
Align the fracture surface and apply ceramic-specific adhesive.
The temperature of the hot air blower is 120℃. It is 15cm away from the ornament and heated for 5 minutes until the glue is cured.
Fix it with fixtures for 24 hours to ensure complete adhesion.
Effect: The fracture is seamless and can withstand the pressure of normal placement.
Fifth, Summary
The core of the repair of ceramic plates heated by hot air fans lies in “precise temperature control, uniform heating and dynamic monitoring”. By rationally selecting equipment, strictly controlling temperature and time, and adjusting the operation mode in real time, the success rate of repair can be significantly improved. Special attention should be paid to the heat resistance limit of ceramics during operation to avoid secondary damage caused by excessively high temperatures or uneven heating. For high-value or complex-structured ceramics, it is recommended to combine X-ray inspection or guidance from professional restorers to ensure the restoration effect and the safety of the cultural relics.
