Stripping the antifouling off a 16-metre hull
Twenty years of paint on top of paint, 16 metres of hull, and three months of weekends with a scraper. This is not a technical job: it is a physical one, and it is the job that governs every other piece of work below the waterline.
Why there is no way round it
As long as the antifouling is there, nothing clean can be done underneath. Osmosis treatment, epoxy primer, and whatever hull coating comes after — none of it keys to layer upon layer of aged paint.
It is also the only time you really see the hull. Under twenty years of paint you find what nobody has looked at in a long while: blisters, old repairs, the real state of the gelcoat.
How long it actually takes
The honest answer, for a 16-metre boat with one or two people on it: about three months of weekends, mid-January to mid-April in our case. Not three months full time — three months of Saturdays and Sundays, piece by piece, side by side.
The last weekend, the one that finished the job, gives you the scale: eight hours of scraping on the Saturday, in the rain, then the bow section on the Sunday from 8 to 11:10. Bruised arms, mosquitoes, and a hull bare over its whole length.
If you are planning, count in weekends, not hours. It is the only unit that holds up when the boat is a four-hour drive away.
The order that saves your arms
The rule we ended up working to, and wish we had known at the start: do the worst bit first, while you still have energy.
| High area, just below the waterline | Arms above shoulder height, bad scraping angle. Attack it first, in the morning. |
| Stern and propeller boss | Geometrically the most awkward areas. Middle of the day. |
| Bow section | The paint holds on harder: allow more time than the surface area suggests. |
| Low area | Comfortable angle, it goes quickly. Save it for when your arms give out. |
What you need
The tooling is trivial next to the time spent. What we actually spent on this job:
| Scrapers and spare blades | €64 |
| Masks | €36 |
| Epoxy primer, 2.5 L (the next stage) | €481 |
| Finsulate hull coating (still to come) | €4,700 |
Blades wear out fast: buy far more than seems reasonable. The mask is not optional — you are scraping old paint of unknown composition.
The details that cost you a day if you get them wrong
- Take the skin fittings out before scraping around them. We removed the galley one so we could work cleanly in that area — and it needed replacing anyway. The detail is in the skin fittings guide.
- The weather decides. You can scrape in the rain; you cannot sand or apply anything afterwards. Scraping is the only stage that tolerates bad weather — so do it when it is miserable and keep the good days for the epoxy.
- Finish one area before opening another. A hull half-scraped everywhere is more demoralising than a hull a third scraped properly.
- Plan the epoxy filler for straight afterwards. The old skin fitting housings get filled while the hull is bare and dry.
What comes next
Bare hull → treating the defects and epoxy filler → epoxy primer → hull coating. Each stage needs the one before it finished and dry, which makes stripping the critical path of the entire hull job: until it is closed out, nothing else below the waterline can move.
The weekend that finished the job is written up here: a weekend alone, a whole hull, and arms giving out. All the hull spending, with the invoices behind it, is on the budget page.