Spraying CLEAR COAT

[Beer-30]

I'm not a big fan of clear coats over gelcoat.
Where clear comes in handy is for years of polishing. When you buff with a machine, the oxidized material tends to swirl around with the compound. When you cross over colors - let's use red and white - the red material gets in the pores of the white and vice-versa. So, when buffing clear, it is all the same, even when you cross over. Makes for a nicer finished product.
It also adds depth, giving a shiny layer on top of the color. Same as on your automobile(s).

[Kamclic]

My rudimentary concepts of paint and coatings is that, without proper skills and preparation, the spraying of any coating over an existing surface leads to very disappointing results. Having said that I cant imagine how your decal would hold up without the clear coat if was torn with clear coat on. For the price of a second decal maybe you could try it without and see how it works out?