Guys,
I learned a lot of my body working stuff from my uncle, who owned a body shop in the 60s, so I guess I was schooled by an "old timer." Here is my humble opinion.
The red glazing putty works fine, if you use it as it was intended - VERY VERY VERY THIN. If you use it to fill a pin hole or a hairline scratch, it works great (over primer). Most people try to do too much with glazing putty and it turns into a huge mess.
If you are dealing with anything larger, sand down to bare metal and fill with a two-part body filler, then reprime. Good luck.
- K
