Scraping antifouling paint by hand is a tough and dirty job. After three long days of hull and keel scraping, Ali Wood reveals the best paint scraper and learns some valuable lessons about paint removal
After a season on the water and two years in a boatyard, Maximus’s antifouling was old and flaky. We’d been given the 28ft Maxi 84 by PBO reader Daniel Kirtley, and one of the first things he suggested we do was scrape back the antifouling to the bare hull. Not a job to be taken lightly!
However, in the process, we did learn that by far the best scraper for removing antifouling paint is the Bahco scraper. For Maximus’s hard paint, nothing else would do (and we tried several).
Delightful Dell Quay
Arriving at Dell Quay in Chichester, we drove past rows of tightly packed boats, the first few sporting gleaming topsides and newly primed hulls, later ones flaking antifouling and old varnish.
Some were missing masts, others missing keels. There was one keel without a boat that was periodically moved around the yard. Each week I’d wonder where I’d find it and if it would ever be reunited with its hull.
Maximus was about as far as you could drive without crashing into the tractor or the farmer’s field.
There’s a tacit understanding among boat owners that the further away from the slipway you’re placed, the less likely the yard thinks you’ll get afloat.
Boatyard pecking order
My neighbour Matt, the owner of a steel yacht built by his grandfather, was hopeful he’d be bumped up in the pecking order after being moved forward for a professional shotblast. Alas, he was promptly reunited with Maximus by the hedgerow. Not to worry, I had good company on the Fridays when we both worked on our boats.
From the top of the coachroof you could just about see the sun setting over the masts in Chichester harbour, and what a sight it was… it made the thought of those long days ahead worthwhile.
What the survey said
During the survey, our marine surveyor Ben Sutcliffe-Davies scraped off the antifouling in a few different places and noted that it was a classic case of mixed antifoulings that weren’t compatible with each other. The good news: they’ll be easy to scrape off. The bad news: like Daniel had said, we were going to have to scrape back to the epoxy.
“It doesn’t take a lot to get the initial product back,” said Ben, scraping away at it. “You’ve got the hard antifoul underneath and below that is the epoxy – a green and a grey, which is how they used to be designed to guarantee the coverage between the two coatings.”
It was inevitable; after a few years the thickness of paint on your hull builds up to the point when it needs to come off. Self-eroding antifouling should, as the name suggests, gently remove itself during the year but layers of hard antifouling, and even old layers of the eroding type, will eventually build up.
We looked at a few different antifouling options and decided on a new product, Seajet’s Bioclean, which is biocide free. When I contacted them, they too advised to scrape back to the epoxy. There was no getting out of it!
Hard working weekend
My parents-in-law kindly offered to look after the kids for three days. They do this every year, only instead of going to a B&B in Lyme Regis, dining out and fossil hunting, this time my husband James and I spent our romantic getaway scraping the boat’s hull.
Are you sure you don’t want to just pay to get it shotblasted like Matt’s boat? James asked.
“Of course not!” I replied. “How hard can it be?” These words would come back to haunt me when, over May bank holiday (including my birthday), we spent three searing-hot days in full PPE scraping paint.
Best PPE for removing antifouling
Antifouling is nasty stuff and it’s essential you wear protective clothing, whether removing antifouling or applying it. You need to capture all debris and scrapings and thoroughly clean up afterwards. Don’t re-use PPE, other than goggles (I washed mine after each use) and use only warm soapy water (no solvents or thinners) on your skin afterwards.
From Screwfix, I bought some Dupont Tyvek disposable coveralls, a pack of 10 Dräger dust masks, and some safety goggles. I wore two pairs of gloves – a thin pair of disposable gloves to keep the paint off and then a thicker, latex grip pair, on top to avoid blisters.
Initially I tried wearing the thick gloves only but the antifouling soon found its way through the fabric.
We got through lots of disposable gloves (and still do) so the pack of 100 was perfect.
In spite of wearing all this, I still got covered in paint. In particular, the area around the edges of the mask and goggles was thick blue. Antifouling dust found its way through the pores of the breathable suit. On the first day I hadn’t quite zipped to the top. It took me half an hour in the shower, scrubbing my skin red raw with a bar of soap to get it off, and still I had a ghostly blue pallor to my complexion when we went out for dinner that night.
Under my overalls I wore a very old pair of shorts and vest, which I had to throw away afterwards.
When everyone’s an expert
During our time at the boatyard, people kept coming up to us and querying why we hadn’t just tried sanding back the old antifouling.
“Nah, you don’t want to be doing it that way,” said one bloke. “It’s a nice boat, that. Why do you want to be spoiling it? Look, what a mess you’ve made! You’ve done some proper damage there.”
Uh-oh! Gouging the hull
It was true I’d gouged some thick scrapes into Maximus’s hull with the edge of the Bahco scraper. It looked like our cat had been sharpening his claws on it.
James told me to take no notice, but feeling uneasy, I took some pictures and sent them to marine surveyor Ben, who was on holiday in Corfu. He called me straight back and congratulated me on a good job, adding not to worry about the scrapes on a boat this old. They could easily be filled with filler or even just dabbing primer. I told him what the man had said, and he laughed: “Welcome to the world of boat ownership, where everyone thinks they’re an expert!”
Which scraper was best?
On the first day I’d brought with me a £9 pack of scrapers (decorator knives) from Screwfix, which had proved very good for removing the old varnish on the companionway.
I also ordered a Draper heavy-duty soft grip stripper/scraper which scored 4.5 on Amazon – this cost £9.25 plus £3.60 for extra blades – and a Bahco 665 carbide edged heavy-duty paint scraper. At £26.50 this was fairly pricey but I knew from searching forums and previous PBO antifouling articles that it came highly recommended.
James started with the Bahco and I took the Draper scraper. After just an hour he’d scraped a 2m wide patch on the hull and all I’d managed was a 30cm patch. We swapped, just to check it wasn’t technique, but James too struggled with the Draper tool which didn’t seem cut out for this particular kind of work.
I soon moved on to other jobs, because it was a waste of time using the Draper scraper on the hull. We’d have to go and buy another Bahco.
Removing antifouling: Top tips
When James got tired he swapped with me. Holding the handle of the Bahco in one hand and the knob in the other to steady it, I followed the curve of the hull, top to bottom, in even sweeps.
Antifouling rained down on me, gathering in pools on the tarpaulin. The noise jarred my ears like nails on a chalkboard, and every muscle in my arms screamed at me to stop. Still, it was hugely satisfying to see the grey and green epoxy emerge from the hull below. Some areas came clean with the first scrape; others needed going over two or three times.
As mentioned, I did find the Bahco gouged the hull, and was later advised I should have filed down the corners of the scraper.
Removing antifouling around the waterline
We found the area around the waterline almost impossible to remove, and when I mentioned this to Ben, he said just to leave it, and sand it back.
On the second day we went to Force 4 Chandlery in Chichester, hoping to find another Bahco scraper but they didn’t stock them. Instead, I bought a Draper 4-edged scraper with soft grip handle and knob. Four blades… at least one of them ought to do the job, right?
Sadly not. The softer, flakier areas responded OK to the Draper scrapers, but where the antifouling was thick and hard, only the Bahco worked. Not all areas of antifoul were as hard to remove. I finished the keel with the Draper, and I tried all four blades, but they soon blunted.
I found if I threw my whole body weight into the scrape, the paint came away easily from the cast iron. It was quite a surprise, after getting used to the grey and green of the hull epoxy, when the bright orange rust appeared from the keel.
Bahco paint scraper the best for removing antifouling
By the morning of the third day we’d finally finished. If we’d had two Bahco scrapers, I think we could easily have done it in two days.
Ben, who used to work in a boatyard, said they could do it with two men in a day, but obviously they were skilled workers, James and I are (brand new) DIY-ers. Plus, it was a physically exhausting job, and I’m not sure I had the patience and stamina to do any more. I quickly got tired and bored, and thought of the other things we could have been doing on our sunny bank holiday weekend.
Fortunately, on the third day, we finished early. We filled three full heavy-duty bags with paint, dropped it in the hazardous waste bin, and headed off to the gorgeous village of Bosham for ice-creams.
Would I scrape off antifouling again? No. Absolutely not! But there’s truth in the expression, “you have to do a job first to understand why it’s worth paying someone”.
Thanks to our Project Boat Supporters
Dell Quay Marine, Osculati, Raymarine, Shakespeare Marine, TruDesign, Screwfix, Coleman Marine Insurance, MDL Marinas, Premier Marinas, seajet,, Clean to Gleam, West System, Farécla, Navigators Marine, RYA, Aqua Marine, Ecobat, Victron Energy, Scanstrut, T Sails and XP Rigging.
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