My hull has been attacked by Port Hacking barnacle, I have routinely scraped them off in the water, before I set off north, I give her the third scrape off, with a plastic scraper.
I intend hauling out up north and was wondering how to sand or burnish the existing AF back to a smooth keyed surface, for the new AF.
The barnacle residue is what I want to remove, so the surface is smooth.
I realise a proper breathing mask is required. Has anyone done this and what type of sander/ sand paper worked best?
cheers Richard

I can recommend the Boat works - great spot who take care of your boat like their own. If only they had a second operation in NSW. I scrape and wet and dry sand in the water. On an outgoing tide on hard racing antifoul. I use 60 or 40 grit wet and dry.

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Kankama said..
I can recommend the Boat works - great spot who take care of your boat like their own. If only they had a second operation in NSW. I scrape and wet and dry sand in the water. On an outgoing tide on hard racing antifoul. I use 60 or 40 grit wet and dry.

Wow, I wouldn't like the ecology gestapo to catch you at it.

I hate barnicales
My mates cat, the last antifoul he used wasn't the best.
Upgrade your plastic scraper to metal, that gets the stubborn big ones off

I would clean off the barnacles in the water. The residue is the problem and this is a job for coarse wet and dry used wet. I have one of these

www.tradetools.com/product-range/air-tools/air-sanders-and-polishers/renegade-50mm-inline-sander

I have only ever used it dry on cars and boats but I reckon it would work well on antifoul and shell remnants. One bloke using the machine and a mate standing there spraying the work with a hose. Random orbital would work well too.

www.ebay.com.au/itm/5-Pneumatic-Round-Air-Random-Orbital-Sander-Sanding-Polishing-Tool-Max-10000RPM/232857773517?hash=item363767a5cd:g:2UQAAOSwYgNbUs63

Position your compressor in a nice higher and dry position and take care with the power leads. Give it a go and report back!

I'm probably at the other end of things, as I race, but my thought is to not let the boat get to that point. I generally dive on mine every fortnight, giving the lightest of wipes to keep the slime off.

But if you're already dealing with barnacles, it's a hard scrape with a metal scraper to get those guys (and the white bits they leave behind). When the boats out of the water, it gets a high pressure wash, then hand wet sanded with 80 grit wet and dry. Doesn't need too much, just enough to take away the smoothness. Slap on some primer anywhere you've gone beyond the antifouling and you're good to go.

Probably depends if its hard or soft antifoul but on soft i find a new sharp metal scraper is the go. I use a nice stiff one that you can put some weight behind and i remove a thin layer of antifoul along with any barnicle glue. Keep the surface wet and the scraper sharp and it leaves a nice smooth surface without the dust. You could give it a quick sand with an orbital as well but i generally find it doesnt need it.

Use Metal paint scrapers. The main body of the barnacle is easy to take off. The base plate not so. I spent days scraping back layers of the base plates that a previous owner had been putting new antifoul over top of. Haven't had barnacle problem since. Better antifouling or barnacles less prevalent in my local area?

WATER WATER WATER EVERY WHERE AND NO DUST EVER!

AF should only be sanded WET, if you do it dry you should be in a spray suit with hood, goggles, gloves and a dust respirator.

Doing it wet you really only need rubber gloves but a spray suit will keep your clothes clean.

Remember if you apply AF with a roller you will need a minimum of THREE coats.

Check the product information.

Thanks everyone for your input, I get the wet theme, to eliminate poisonous dust. I'll give her a metal scrape this week end, before setting off for a Northerly sailing adventure, for the next 6 months.
I intend hauling out at my north destination and doing what was only done last August.
cheers Richard