I started one s & g kayak with RAKA epoxy and finished it with MAS epoxy. I have had no problems with it at all. That was two years ago so I think if there were any problems they should have showed up by now. I always wash , lightly sand or use steel wool and rewash before I epoxy over cured epoxy. I did all my work in 30 to 45 degree weather so I needed a long time for the epoxy to cure.