| Composition of ingredients | Containing only resin, pigment, and solvent (without curing agent), it forms a film by solvent evaporation and drying. | Composed of main paint (resin+pigment)+curing agent (isocyanate)+diluent, it needs to be mixed and undergo chemical reaction for curing. |
| Drying/curing principle | Physical drying: relying on the natural evaporation of solvents, the paint film gradually hardens (greatly affected by environmental temperature and humidity). | Chemical curing: After mixing the main paint with the curing agent, a cross-linking reaction occurs to form a dense network structure (with controllable drying speed). |
| Drying time | The surface dries quickly (about 10-30 minutes), but complete drying takes several hours to a day (slow solvent evaporation). | Dry for 15-30 minutes, dry for 2-4 hours, and fully cure for 24 hours (complete chemical reaction). |
| Hardness and Wear Resistance | The paint film is relatively soft (pencil hardness about HB-B), easy to scratch, and prone to wear and tear due to long-term friction (suitable for temporary repair or low-cost needs). | The paint film is extremely hard (pencil hardness 2H-3H), wear-resistant, scratch resistant, and has strong resistance to stone impact (suitable for long-term use as topcoat/primer). |
| Adhesion | Generally, the adhesion to the substrate (such as metal/plastic) is weak, and it is necessary to rely on the primer to enhance the bonding. | Extremely strong, the curing reaction forms a chemical bond between the paint film and the substrate (especially when combined with specialized primers). |
| Construction convenience | Simple: No need to mix curing agents, can be used immediately, suitable for beginners or small area repairs. | Complexity: It is necessary to strictly mix according to the ratio (usually 2:1 or 4:1 main paint: curing agent), and precisely control the amount of diluent added (errors affect the curing effect). |
| Applicable scenarios | -Temporary repair (such as covering small scratches)
-Interior/non exposed parts painting
-Low end demand that is cost sensitive | -Original factory paint/repair paint for automobiles
-High end modification/exhibition car painting
-Industrial components that require long-term durability, such as bumpers and wheels |
| Storage stability | Stability: unopened can be stored for 2-3 years (away from light and at room temperature), and should be used up as soon as possible after opening (solvent is volatile). | The main paint is stable alone (1-2 years), but it must be used up within 4-8 hours after mixing (cannot be continued after the curing reaction is initiated). |
| Cost | Low: The unit price is cheap, and there is no need to purchase additional curing agents. | High: The unit price is relatively high and requires the purchase of curing agents (increasing the total cost by about 30% -50%). |
| Typical usage examples | Repairing minor scratches on the car body (temporary covering), refurbishing interior plastic parts, and low-cost model painting. | Original factory new car paint, accident car full body repair, high-end customized car paint (such as metal paint/pearl paint), and protective coating for racing car components. |
