Thanks for the replies. I'm trying to get the non slip off as the previous attempts to paint (sanding, undercoating and topcoating) the roof end with the new paint lifting off after 6 months or so.
The roof is relatively sound doesn't need much patching and there seems to be at least two layers of paint underneath the non slip which is OK and I'm happy to use this for a base to prime.
I can achieve this by using discs but it's a slow process and there appears to be a local shortage of sanding discs...all the DIY superstores are completely out of all of them, whichever size, grade or type...bare shelves. I've been getting some from Screwfix but they're 50 grit..hence the question about going for a grinder/metal cup.
So questions are.
1. Can I get better quality discs?... Screwfix ones don't seem great. I can get stuff delivered home but it's 100 miles from the boat so can't get stuff to hand overnight. I'm working all next week so intend to get tooled up ready to attack it the week after.
2. Is there something between a sander and a cup grinder which will help me get back to the basecoat but not the metal. thinking of a plastic/nylon type wheel?
I've allowed most of the summer for this job along with painting the sides..so no rush and I know it takes elbow grease!
Thanks
G