Determination of varnish finish performance on painted surfaces

Regarding the finishing properties of varnishes (or paints) on surfaces, it is determined as follows: a pre-prepared well-decorated wooden or iron board (dimensions 200 x 400 mm) is debrushed with the varnish to be tested. No. 12 dry brush or brush, remove the paint on the four sides of the board, and then distribute it on the entire surface, in order to brush into a very uniform coating film.

It must be brushed parallel to the long surface of the board first, and then brushed vertically. The brush needs to move as straight as possible from one side of the board to the other. After that, squeeze the brush on the four sides of the board and use The excess varnish that is extruded is carried out on the third layer, that is, the last layer of brushing, so that it is carried out parallel to the long surface of the board. If the brush can move freely and easily during construction, and the varnish does not pull the brush, then the varnish method Performance on the surface is considered acceptable. (Related instrument: applicator)

It is necessary to keep the paint removal room absolutely clean. The test clothes and hands of the test personnel, as well as the surface and brushes to be removed should be absolutely clean. After the test, hang the test panel upright so that the painted surface faces the wall.

A properly painted surface should not show any sag after drying (relevant instrument: sag meter), as this indicates either too much paint on the surface or a very textured application.

In order to determine the brush-off performance of varnishes and paints on surfaces, a number of test methods based on the use of well-known tools are proposed.

For example, it is mentioned in the literature that there is an instrument composed of a round wooden disc that rotates horizontally at a constant speed. The standard brush for paint removal is fixed on the red rod, and the lever is connected to the device for measuring the pressure of the brush through a spring. together.