advice on removing underseal on arches and replacing with por15

[C2AXG]

My arches are in need of some tlc, obviously being undersealed on arrival in the UK but since its flaked in places and looks shit!
want to remove the lot and use some por15 then por15 topcoat in white to freshen it up.

any advice on how to remove the original crap that obviously wasn't made to last?

 

[Rom]

Need to know what it is really. Can you get pictures, as then i can give a better answer.

Likely its just black schultz or stonechip if its a rubber kind of textured layer. Unlikely to remove without some surface damage, from wither scraping, or wire wheel etc.

If you dont fancy stripping it all back, id peel off all the loose stuff, and redo it with decent stonechip, you can build it up to cover the missing patches.