Removing a ‘fair few’ layers of antifoul with orbital sander?

[fredrussell]

Anyone done this? I’m thinking that with a hoover attached and using decent Mirka pads it might be preferable to scraping. My hope is that with the hoover attached the pads will clog up less quickly.

I know that blasting is the preferred method, but I’m skint.

 

[Minerva]

I think your shoulders would hate you and you'd be regretting it after a 12" square bit of hull sanded after over an hours hard work.

If you must do it and it's a thick build up, a good scraper will likely be easier* and Faster**

If it were me, I'd slap another coat of antifoul on for next season and put £50 aside each month for the next year to get a mobile blaster to come and do it.

*still bloody hard work

** a snail slithering a marathon would likely be quicker.

 

[AntarcticPilot]

Anyone done this? I’m thinking that with a hoover attached and using decent Mirka pads it might be preferable to scraping. My hope is that with the hoover attached the pads will clog up less quickly.

I know that blasting is the preferred method, but I’m skint.

Don't do it dry. Antifouling dust is toxic, and even with a vacuum attached, the dust will escape. Further, I think you'll find that a good scraper is faster than sanding it off. There's also the issue that most yards these days want antifouling to be removed in a designated area so that the dust/scrapings don't contaminate the ground.

 

[wombat88]

I have never enquired, how much does blasting actually cost, for example on a 20ft boat?

 

[Momac]

I tried dry sanding for about 10 minutes and gave up . As said a health hazard.
Wet sanding was messy but less hazardous to the lungs.

 

[Chiara’s slave]

We took 20 years worth off Chiara last year, chemicals, jet wash, then hand scrapers. Brutal, slow, cheap and effective. We spent more on chemical stripper than we should have, the boatyard gently told me afterwards that experience had told them when to stop stripping and start scraping. They don’t do blasting or dry sanding in their yard, too messy, plus environmental and H&S issues.

 

[AntarcticPilot]

I have never enquired, how much does blasting actually cost, for example on a 20ft boat?

in 2014, grit-blasting a Moody 31 cost around £850. Given that area scales as the square of the length, I'd expect a 20' boat to cost around £400 at 2016 prices. Of course, I'm ignoring fixed costs like travelling and set up, so the ratio might not be so favourable - I'd guess that £500 might be a reasonable ball-park.

 

[Praxinoscope]

Just don’t, as pointed out earlier it’s toxic.

 

[Tranona]

I have never enquired, how much does blasting actually cost, for example on a 20ft boat?

Around £250-300 for just the hull, more if you want an iron keel done as well.. There is usually a minimum fixed cost of getting the gear on site so having more than one boat to do helps cut the cost. A good operator can do 2 or 3 boats in a day.

 

[Wansworth]

If not racing,scrape off loose and apply antifoull

 

[Refueler]

Anyone done this? I’m thinking that with a hoover attached and using decent Mirka pads it might be preferable to scraping. My hope is that with the hoover attached the pads will clog up less quickly.

I know that blasting is the preferred method, but I’m skint.

Please dont do it ... you cannot keep a level constant surface .... I know - I tried it and the hull ended up all 'wavy' ........... my Alacrity was evidence of it for evermore !! Young and impatient I was !!

A portable large plate belt sander would be better as it will help prevent "valleys and hills"

 

[Chiara’s slave]

Keep it wet. Live longer.

 

[Wansworth]

Keep it wet. Live longer.

All these YouTube vids of people working on their boats show everybody wearing space age dust masks even doing a bit of hand sanding

 

[PCUK]

Your neighbours in the yard won't thank you either!

 

[Spirit (of Glenans)]

It's toxic. messy and will be abhorred by both the boatyard and the owners of neighbouring boats, particularly the downwind ones.

 

[savageseadog]

Caustic soda/wallpaper paste stripper, use scrapers.

 

[Chiara’s slave]

All these YouTube vids of people working on their boats show everybody wearing space age dust masks even doing a bit of hand sanding

Absolutely. I have a suit, remote air feed ans filtration, but I’d still not dry sand antifoul, not ever. The blasting guys suits are way better, and 20 times the cost. I have a mate who does it.

 

[Graham376]

Took me about 2 1/2 days (between beers) to scrape our 38ft boat with 2 handed Bahco pull scraper, then lightly sanded with powerful vac fitted with HEPA filter. As others have said, dry sanding the lot is lengthy, dangerous, not neighbour friendly and you'll look like a Smurf.

 

[iantomlinson]

Took me about 2 1/2 days (between beers) to scrape our 38ft boat with 2 handed Bahco pull scraper, then lightly sanded with powerful vac fitted with HEPA filter. As others have said, dry sanding the lot is lengthy, dangerous, not neighbour friendly and you'll look like a Smurf.

Same here. Did our victor 34. Took a week back to gel coat. Switched between random orbital and bahco pull scraper. Did the smurf impressions. Gelshield and coppercoat. Wouldn't do again tho.

 

[Mistroma]

I have to agree about sanding and scraping is way better. However, some soft anti-foul just moves around with a scraper and would gum up a sander. I imagine chemical or blasting would be needed.

Problem with chemical stripping is that it can make hard fouling soft and difficult to remove. I tried a small area many years ago and that's exactly what happened. I used my Bosch power wood chisel and that took it back to shiny gelcoat pretty easily. I've used it on my current boat and it worked well there. The particles tend to be large as it shatters hard anti-foul and I just swept up a few bucket loads. My mask was still completely clean at the end.

Pity they stopped making that power chisel. Multi-tools don't work as the blade slides from side to side. The chisel moves forwards and backwards (same direction as a scraper). The anti-foul is fragmented and comes off well, or not at all if it turns out to be soft stuff. I let a friend use it and it did nothing on his soft anti-foul. I hand scraper was a lot more effort and didn't work either.

I did a short video years ago when a yard made a complete mess of my anti-foul. They took it completely off in several places. I didn't take it back to gelcoat and left a little of the primer. I just sanded that lightly before putting on several coats of primer.