I know this is a pretty complicated topic, so hopefully it helps to get some quick advice from this article.
First of all, a note about vinyl. Vinyl glazing does have its place, even if it’s very limited. In this case, I don’t think there is anything wrong with keeping this surface to protect vinyl from dust and dirt getting in. There is probably some people who get so much use out of it that they decide that “this area should keep out dust!” So the advice I’d give is to stick to one bead on a surface and replace it when it’s time to remove the previous one, assuming you’re not going to break your glazing.
For this example, I can see what I mean. With a vinyl surface in my collection, I’ve been glazing the surface over and over over, and it comes off in very similar ways. For this reason, when things become problematic I’ll simply pop a second bead at the bottom so all the dirt is out on either side and I’m ready to remove it.
That said, the question of whether you should keep this surface should be a discussion you start with your vinyl’s expert. Some might not like the idea of adding even more glazing surface to their vinyl surface to protect it from dust and dirt. Many vinyl wraps are used as replacement glazing bead wraps, including the cheap plastic glazing that is typically provided with the new glaze. If glazing bead wrap is damaged in transit, it can lead to the glue loosening, which can damage the surface of the glaze. These glazes are most likely to be brittle with very small cracks. To avoid any more damage, replace your vinyl wrap when you purchase your new glaze.
Vinyl glazes for the top of houses are easier to repair, yet have an increased chance of breaking in transit than vinyl laminate products, which are often designed for houses and therefore less likely to cause any damage. In addition, since vinyl wraps are typically placed up to four to six years into the future, the glazing is no guarantee against future breaks in transit, and are also not designed to support long-term use.
Some companies sell glazing beads online for people seeking to repair vinyl that has broken free, rather than for homeowners who simply want to fix the damage. In addition, there are several plastic beads available from these companies, which may be more stable in cross-contamination with vinyl.