How to determine if a paint can is suitable for oil-based paint?

Step 1: Core Assessment of Material Resistance to Oil Corrosion (Most Crucial)

1. First, consider the material type:

✅ Acceptable materials: Tinplate, galvanized steel sheet, metal buckets with anti-corrosion inner coating, and engineering-grade PE/PP plastics labeled as oil-resistant solvents;

❌ Unacceptable materials: Ordinary sheet metal without an anti-rust layer, and ordinary low-priced plastic buckets-ordinary plastics will be corroded and swollen by the organic solvents in oil-based paint, and ordinary sheet metal is prone to rusting and contaminating the paint; neither is suitable.

2. For uncertain materials, simple tests for verification:
Plastic cans: Drip a small amount of the oil-based paint to be filled onto an inconspicuous spot on the inner wall of the can. Let it stand for 24 hours. If there is no stickiness, deformation, or dissolution, it is acceptable; otherwise, it is unsuitable.
Metal cans: Scrape the inner wall of the can to check for a complete anti-rust coating. If no rust is exposed after scraping, it is acceptable; if it is already rusty or rust is exposed after scraping, it is unsuitable.

Step 2: Check if the sealing performance meets the standards. Oil-based paints contain a large amount of volatile organic solvents. Inadequate sealing will lead to solvent evaporation, paint skinning, and hardening, rendering the paint unusable.

✅ Qualified requirements: The can lid is a screw-on/snap-on lid with a built-in rubber sealing ring on the inside. It should not leak after being laid flat for 24 hours, achieving complete airtightness.

❌ Unqualified conditions: No sealing ring, large gap between the can lid and the container body, and gas can be felt flowing out when pressing the container body. This type is not suitable for long-term storage of oil-based paint and is only suitable for short-term use on the same day.

Step 3: Matching Usage Scenarios

1. Short-term use (used within the same day/1 week): As long as it is made of qualified tinplate material and has a basic seal, it is perfectly suitable;

2. Long-term storage (used in multiple installments over more than 1 month): It also needs to be made of stainless steel/a metal container with a complete anti-corrosion inner coating to avoid rusting during long-term storage, and the sealing structure must have a rubber sealing ring;

3. High-pressure spraying operations: The can body thickness also needs to meet the standard and be able to withstand repeated pressurization and vacuuming, and it also needs to be equipped with a pressure gauge/pressure regulating valve structure. Ordinary thin tin cans are not suitable.