Appropriate Material Combinations – Spray paint

The difference between acrylic and alkyd enamels, general application guides, and appropriate material combinations.

Properties of single-component acrylic enamels

Unlike acrylic paints packaged in tin cans, acrylic enamel spray paints are not water-based, but rather have an organic base.

Advantages (compared to alkyd spray paint enamels):

• short drying time;
• saturated colors;
• high elasticity and high adhesion to plastics (due to these properties, acrylic enamels are preferable for applying to plastic surfaces).

Disadvantages (compared to alkyd spray paint enamels):

• moderate weather resistance;
• moderate adhesion to metals (requires preliminary priming);
• moderate resistance to solvents.

Properties of single-component alkyd enamels

The difference between alkyd enamels and acrylic enamels is that the chemical processes within the former do not end immediately after drying. When all the solvent has evaporated, the alkyd enamel polymerization process continues under the influence of atmospheric oxygen. Relatively small molecules join together to form a large polymer molecule, thus making the coating more durable and resistant to various influences, but at the same time less elastic and more brittle. However, alkyds have been known for a very long time and have been thoroughly studied. Peculiarities of the above-said polymerization process are taken into consideration in modern KUDO^® formulas, hence even upon complete polymerization, the paint film remains quite elastic. The polymerization process can take from several days to two weeks. The coating must not be subjected to mechanical stress during the polymerization process. For example, a car body part painted with alkyd enamel must not be washed and polished for two weeks. Besides, during the polymerization, alkyd enamel must not be coated with other lacquers, even with those based on alkyd, as the coating may be damaged. Either the wet-on-wet coating technique, where the next coat is applied right after the previous one has dried to touch, should be used, or an additional coat should be applied upon complete polymerization. When the wet-on-wet coating technique is used, adhesion of the newly applied coat is higher than when applied upon complete polymerization. Alkyd spray paints have high weather resistance and do not require additional varnishing.

Advantages (compared to acrylic spray paint enamels):

• high adhesion to metals;
• higher hardness;
• higher weather resistance;
• higher light fastness (fade less);
• higher resistance to solvents.

Disadvantages (compared to acrylic spray paint enamels):

• longer drying time;
• long-lasting polymerization process.

Important! Guidelines for selection of materials required for car paint repair can be found on the 1K metallic automotive repair paint and 1K alkyd automotive repair paint pages.