Determination of sanding property of primer and putty

Grinding properties and instructions

This method is applicable to the determination of the sandability of primers and putties. Sandability refers to the difficulty of producing a smooth and matte surface after the paint film or putty layer is polished (thousand or wet) by pumice, sandpaper and other materials. This method can use instruments or manual methods to polish the surface of the paint film. After the primer and putty samples to be tested are polished for a certain number of times, according to the load weight, the number of times of sanding and the degree of corrosion, observe the surface phenomena of the primer and putty. Assess playfulness

Abrasive instruments and materials

(1) Water sandpaper

(2) Grindability Tester, this instrument is used to evaluate the quality of the primer and putty grindability, through the back and forth grinding of the sample, the number of grindability can be directly read by the counter, and the surface of the coating film Phenomena are assessed

Abrasiveness Determination Method

Put the water sandpaper specified in the product standard on the grinding head of the sandability Tester, place the sample to be ground in the center of the suction cup, and observe the surface phenomenon of the sample after the grinding head has been reciprocated for a certain number of times.

When performing putty grinding, the load specified in the product standard should be added to the grinding head of the instrument.

When grinding by hand, use water sandpaper to rub evenly on the sample plate. It can be dry or wet. When grinding by hand, pay attention to the uniformity of force and grinding speed.

Grinding results indicated

Among the three samples, two samples with similar phenomena are used to evaluate the results. Judgment whether the surface is uniform, smooth and matte, whether there are particles that cannot be worn away or heat and softening, etc.

Qualified or not according to product standards.

Grindability reference standard

National standard GB/T1770 "Determination of sandability of primer and putty film"