Gelcoat with wax vs without wax

[Stuart 28-2]

I'm reading in a repair book about applying gelcoat. In the section about rolling it only mentions gelcoat without wax and goes on to point out the need to brush or spray on PVA afterward so the gelcoat cures.
Does anyone know of a reason to not roll gelcoat with wax?
It seems gelcoat with wax is more readily available, and, this would do away with the need to apply PVA. The book is from 2006 so I don't think it was written before gelcoat with wax was available (although I don't know when that started).

 

[Mike Brockman]

If you use gelcoat with wax and you need to add another coat you will have to sand or the next coat won't stick.

If you use gelcoat without wax you can just roll, spray or brush another coat without sanding and then spray PVA over it when its to the thickness you need. Use the Preval sprayers that you can get a most hardware stores for spraying the PVA. And for small jobs I have also used the Preval sprayers to spray gelcoat, you will need to thin it some.

 

[KS Dave]

I bought without wax and then bought a small bottle of the wax additive to mix in when I needed it. I figured that was a more versatile option as I could use it for either layups (without wax) and/or as a final coat to fully cure it (with wax). One can apply the same methodology with polyester fiberglass resin.