Which grade of sandpaper?
Transocean recommendations for sanding
When repainting an old painting system, sanding has to be done in order to ensure adhesion of the fresh paint layers. The underwater hull should be roughened with a coarse grade but with leaving the undercoat intact. Always wet the hull and sandpaper with water in order to reduce the amount of dust (especially when sanding antifoulings). Do wear protective clothing and mask too. For above waterline areas a fine grade can be used. See the table below to select the right grade for the desired type of work.
Type of work | Corresponding grade of sand paper | |
Wet | Dry | |
Removal of old paint and residues | 80-120 | 40-80 |
Sanding filler or primer | 120-220 | 80-120 |
Final sanding of filler | 220-400 | 120-220 |
Removal of surface defects | 400-600 | 220-280 |
Sanding prior to topcoat | 600-800 | 280-400 |
Removal small paint defects (drips, brush marks) |
800-1200 | 800-1200 |