Sandpaper: the choice of sandpaper for polishing putty is a matter of concern. Here is a systematic discussion. There are 80, 120, 180, 240, 320, 400 and 600 sand paper meshes (sand grains per inch) commonly used in wall grinding. Among them, 80 and 120 can be classified as coarse sandpaper, 180 and 240 are medium, and more than 320 are fine sandpaper. If the sandpaper is too thick, it is easy to cause scratches. If the sandpaper is too thin, it is difficult to polish it flat. Therefore, the choice of wall sandpaper is not the coarser the better, nor the finer the better, but should match with wall putty.

實(shí)際操作中，首先要以能把平整度做好為目標(biāo)，墻面打磨多用240、320先進(jìn)行試打，如果打磨起來不是很吃力，可以把平整度做得很好，那就繼續(xù)；如果感覺打磨很吃力，那就換用低目數(shù)的粗砂紙?jiān)龠M(jìn)行試打。在保證了墻面平整度的前提下，如果一遍使用了粗砂紙，一般整體或局部還需要用細(xì)砂紙?jiān)俅蚰ヒ槐椋韵稚凹埩粝碌膭澓郏⑶易寜γ娓蛹?xì)致。

In actual operation, first of all, we should aim to do a good job in flatness. Wall polishing is mostly used. 240 and 320 should be tested first. If it is not very difficult to polish, we can do a good job in flatness, then continue; If you find it difficult to polish, use low mesh coarse sandpaper for trial beating. On the premise of ensuring the flatness of the wall, if coarse sandpaper is used once, it is generally necessary to polish the whole or part with fine sandpaper again to eliminate the scratches left by coarse sandpaper and make the wall more detailed.

按膩?zhàn)淤|(zhì)量來說。非耐水膩?zhàn)佑捎诒砻娼Y(jié)構(gòu)疏松，所以比較容易打磨，一般都用240、320或更高的砂紙來打，不過由于大多數(shù)非耐水膩?zhàn)淤|(zhì)量都比較差，粉料本身的目數(shù)普遍較低，所以即便用高目的砂紙打磨，也很難打出非常細(xì)致的感覺。

According to the quality of putty. Due to the loose surface structure, the non water resistant putty is easy to polish. Generally, 240, 320 or higher sandpaper is used to polish it. However, because the quality of most non water resistant putty is relatively poor and the mesh of powder itself is generally low, it is difficult to polish it with High-Purpose sandpaper.

耐水膩?zhàn)颖砻娼Y(jié)構(gòu)相對(duì)牢固，打磨要比非耐水膩?zhàn)淤M(fèi)力很多，尤其是一些高強(qiáng)型的耐水膩?zhàn)樱绻鹊侥佔(zhàn)油耆赏负笤俅蚰ィ秃芾щy了，這時(shí)候就需要先用粗砂紙把平整度做好，然后再用細(xì)砂紙打二遍，以求更好的效果。

The surface structure of water-resistant putty is relatively firm, and polishing is much more laborious than non water-resistant putty, especially some high-strength water-resistant putty. It is very difficult to polish until the putty is completely dry. At this time, it is necessary to do a good job of flatness with coarse sandpaper, and then hit it twice with fine sandpaper, so as to achieve better results.