I've applied a primer coat to the Zaku from the Best Mecha Collection "Old Kit" that I'm currently working on.

I did one extra step before the primer. Since I couldn't completely eliminate the seam line in the slit inside the mouth, I sanded it down and then attached it using a cut cable tie.

This time, because there are some modified areas and many seam lines that I've treated, I started with 500-grit gray primer (I usually go straight for 1000-grit black primer).

This eliminated the small scratches, but...
The areas where I filled with gel-type super glue aren't very well done. However, these areas will be mostly invisible after completion, so...

I started building the Best Mecha Zaku (Part 4) | ヘイカユウジ's Gunpla works