Painting over blacking?

[Ricco1]

I'd like to paint a broad red stripe in gloss red, in the traditional style, at the back of my boat, just above the waterline. This area is currently blacked and has no doubt many layers on it. What are the chances of getting a reasonable result if I attempt to sand this area; prime and gloss?

 

Thanks.

[dave moore]

You first need to remove whatever is already there. If bitumen, it's likely to clog any abrasive easily. You could try to burn it off using a blowtorch and scraper then clean the exposed steel back to bright using cup brush, flap wheel etc before priming, undercoating and glossing. In the water, it's not going to be any fun at all, access wise.....if you can get at least the stern end out of the water things will be much easier.

 

Dave

[bizzard]

Ideally get all the bitumen off first as Dave Moore explains, but there is also another method, not so good but it works quite well. Bitumen paint burns and leaches through most paints, but aluminium paint,or aluminium wood primer will seal it in quite well. And then proceed with the finishing coats.

[Pete & Helen]

When I had my boat blacked last time the yard used a high pressure water jet to clean the old stuff off. At least it may get a good proportion off for you

[Claude]

Personally I wouldn't be scraping blacking off the hull at (or just above) the waterline. That's exactly where blacking is needed, not a decorative red line!

[Neil Smith]

You can get a mini sand blast gun that works well on small areas, Also do them now and again for about £30.

 

Neil