Wet drywall sanding?

[dgadee]

I have to get a lot of dead antifoul off and no way am I going to scrape it and the quote I got for blasting is not going to be paid. It seems some use drywall sanding techniques, wet:

Sanding antifouling

Some posters on YBW (Easiest way to sand antifoul) promote the technique.

What's the best grit to use? How much comes off - would it remove down to the hull level?

 

[NormanS]

I wet sand my antifouling every year, using gauze abrasive on a dry wall pole. It comes in a roll specially for use wet. (Tool Station, for example at £5.95 for 5m). I had my antifouling blasted off about 12 years ago, and am determined not to let the thickness build up. If your a/f is already thick, you'd be better scraping off the worst of it and then sanding. Sanding alone, would be a long wearysome job.

 

[Iliade]

I use a shortened hoe with rounded corners, a stiff wet broom, then paint. All done on the piles within one tide.

If the af is very thick, the hoe is sharpened ;0)

If I felt the need to cut back to the gel coat I would go for wet blasting with soda or similar. Life is too short to do it manually and it could well be shortened even more by doing so...

 

[Quandary]

If the antifouling is thick enough to need to come off scraping it is not hard once you acquire the knack and using the right tools. Can not imagine that wet sanding it would be either easier or quicker

 

[dankilb]

Or wet machine sand with a large compressor (hire type)?

I’d go 80 grit. Ideally mesh (gauze) discs, as suggested.

How much comes off depends on type/condition. Our was soft but surprisingly well adhered, so it clogged/took a lot of sanding. Went for slurry blast in the end and swallowed the cost.

 

[TernVI]

Sometimes it crazes when it dries out fully, then it scrapes off in flakes quite easily,
Othertimes, it's best to attack it when it's as wet as possible, you can get a lot off with a wet sanding sponge if you just turn your brain off and get on with it.

 

[Graham376]

If the antifouling is thick enough to need to come off scraping it is not hard once you acquire the knack and using the right tools. Can not imagine that wet sanding it would be either easier or quicker

Having dry scraped a 38ft boat a couple of times after trying sanding, I agree. Couple of days of easy but boring work and far less mess than sanding.