How many labour hours to remove bottom paint on a 30ft Grady-White?
I have a client wanting an estimate to completely remove the bottom paint on a 2018 30-foot Grady-White. They want it taken down to the bare gelcoat. Roughly how many labour hours should I quote for this complete job?
Answer
Removing bottom paint from a 30-foot Grady-White takes between 15 and 45 labour hours, depending on the removal method and the paint condition. Because this 2018 hull carries only five or six years of buildup, expect to hit the lower end of the scale using chemical strippers or media blasting.
Manual Sanding and Scraping
If you tackle this with a scraper and a random orbital sander, quote 35 to 45 labour hours. A 30-foot Grady-White, such as a Marlin 300 or Canyon 306, has a beam of 10ft 7in and a deep-V hull. This gives you roughly 350 to 400 square feet of wetted surface area. Working overhead with a 6-inch dual-action sander is exhausting. Progress remains slow.
You need a heavy-duty sander like a Festool Rotex RO 150 or Mirka DEROS hooked up to a HEPA dust extractor. Start with a carbide pull scraper, such as a Bahco 650, to break the crust. Move to 60-grit or 80-grit Abranet discs to take the remaining paint down to the gelcoat. Always wear a P3 respirator, goggles and a Tyvek suit when removing toxic antifoul to prevent inhaling copper and biocide dust. Working around the outboard bracket, through-hull fittings and lifting strakes slows the job significantly. Expect to consume £80 to £120 worth of sanding discs.
Chemical Stripping
Using a marine paint stripper reduces the physical labour and drops the time estimate to 15 to 25 hours. Products like Peel Away Marine or Sea Hawk Marine Paint Stripper are highly effective on ablative paints.
- Application (3 to 4 hours): Trowel or roll the paste on thickly. You will need three to four 20-litre tubs to cover a 30-foot boat.
- Dwell time: Cover the paste with the supplied laminated paper or a thin plastic sheet to stop it drying out. Leave it alone for 12 to 24 hours.
- Removal (8 to 10 hours): Slide a broad putty knife or plastic scraper under the paper. The paint comes off in wet sheets directly into a hazardous waste disposal bag.
- Cleanup (4 to 6 hours): Neutralise the hull by washing it down with a stiff brush and water. Run over the hull lightly with an 80-grit sander to remove stubborn patches and key the gelcoat.