Re-coring question

[CHANCE1234]

I used system three fairing compound cause I had it left over from anothe project. All resin will be poly because that is what I have used for everything and have a gallon left over. However you got me thinking now. Poly won't adhere to epoxy products well from what I've heard but epoxy will adhere to poly. Can anyone verify that or is it one of those old wives tales. It's just a hatch so I think I may still stick with the plan of using poly resin over the system three fairing and cross my fingers...