Stonechip Underseal OVER POR 15?

[Darkcat]

Afternoon all!

I have just replaced the sills and floor on my other fun car, my mini.
As i had a fresh tin of POR15 in the garage that came with the "odds and sods" box with my last chim, i though id treat the bare areas to some POR to help stop it rusting.
However, i have read that its not easy stuff to paint over - im not looking to paint body paint over it, but want to coat the sills in stonechip underseal so it matches the other side.

Can this be done without investing in POR15's intermediate coat, or if i just scuff it up with some 600 grit will the stuff stick?

also, ETA: does body filler stick to POR?

Edited by Darkcat on Friday 26th July 16:39

[roseytvr]

I have had no problem covering POR 15 with waxoil and underseal in the hard to reach areas. Should be ok.

[penno]

ive put stone chip primer with schultz gun over por15 and its been great. athlough the por15 chassis paint has started to flake in places from the primer which is odd