The Importance Of Sandpaper in Sanding

1. Use of sandpaper

 

When using sandpaper for manual polishing, generally cut the whole piece of sandpaper into four pieces, fold each piece in half and clamp the two ends with your thumb and little finger. In addition, press the three fingers flat on the sandpaper to sand the surface of the object back and forth.

 

According to the sanding object, it can be changed at any time, and the cavity in the finger and the stretching of the finger can be used to grind flexibly in the concave-convex area and the corner.
When sanding a large area, it is necessary to grasp the principle of "subject to the height". The sandpaper should be rotated with the palm of the hand, or it can be lined with a slightly harder rubber such as a sponge or cork. grind.
The nail length of the sander should be moderate, and the finger should be avoided during the operation.

 

2. Causes and solutions of sand marks

 

(1) Reason

 

Sanding against the wood grain; sanding with too coarse sandpaper; sanding before the paint film is dry; using too slow drying solvent, so that the paint film cannot dry in a certain period of time; the upper paint film is too thin; the paint cannot penetrate without thorough cleaning after sanding; When the sandpaper is used, due to the retention of paint powder on the surface, a certain part has no sanding function, which will cause movement marks.

 

(2) Solution

 

a. Choose the most suitable sandpaper. Generally, the sandpaper used for the first sanding is thicker, and the sandpaper used for the second sanding is finer, and the sand marks on the upper layer should be worn off;

 

b. When grinding, it should be polished according to the direction of the wood grain and along the direction of the wood grain;

 

c. Sanding should be carried out after the paint film is dry, and dust and paint powder should be removed;

 

d. After using the sandpaper for a period of time, check whether the powder is retained and replace it;

 

e. Properly adjust the viscosity of the paint, and grasp the thickness of the paint film spraying, enough to cover the sand marks.