Serb1980 said..
Hi everyone,

my boat is full of barnacles but anti fouling was done 1/12/21. Is this normal? Diver went to clean the boat 1/3/22. Should I give them a call back? I been told that I shouldn't worry and that paint will last for 12 months. any thoughts?

Thanks

Who did the antifouling, you or a "marine professional"? A couple of good coats of a reputable brand antifoul paint properly applied should last at least 12 months.

Most likely cause is not preparing the surface properly before applying the anti fouling paint.
To do a lasting job you need to remove the build up of old flaky antifoul till you have one nice even surface, then primer, then at least 2 coats of antifoul.
The first step is the most important part.

UncleBob said..

Serb1980 said..
Hi everyone,

my boat is full of barnacles but anti fouling was done 1/12/21. Is this normal? Diver went to clean the boat 1/3/22. Should I give them a call back? I been told that I shouldn't worry and that paint will last for 12 months. any thoughts?

Thanks

Who did the antifouling, you or a "marine professional"? A couple of good coats of a reputable brand antifoul paint properly applied should last at least 12 months.

Gladesville bridges marina has done the job. I will give them a call tomorrow. Probably only one coat was applied. Will I damage the boat if I remove barnacles with a brush from the dingy?

If the boat is not moving much, stuff will still grow on antifoul, but its easier to get it off.
Check to see if it is:
-- ablative. Soft or self ablating, comes off as you move through the water. Hence it needs to be redone every 12-18 months as its all gone; or
-- hard. Doesn't come off as you move through the water. But after a few seasons you end up getting multiple layers you'll eventually need to strip back. Still redo it every 12 to 18 months.

You can wet sand hard antifoul or use coarse brushes, but ablative you need a bit more finesse. Scrub ablative with a hard brush and you'll end up swimming in a big blue/(insert antifoul color here) cloud of it.
I had a diver do a hull clean once a month. If I left it any longer than that you could feel it was a little bit sluggish from the slime when motoring or in light airs. Some guys don't get a regular hull clean at all and rely on regular sailing to keep it clean.
Horses for courses mate.

I always wet sand my boat to a very high standard every time I antifoul, she has no buildup of old paint and after 22 years I can still get back down to primer at some patches. I use 2-3 coats of Wattyl Seapro 120 and I always get some barnacles. I probably get out to about 4 months before one or two make their mark. I clean these off and give the boat a little scrub with some 60 grit. The Wattyl is a hardish paint, whch is why I use it, and can take the sanding. I would love a paint that lasts longer and is hard enough to sit the boat on the sand. I usually have to antifoul every 18 months but the last 6 months the swims get more regular.

Because my boat is a cat, it is very easy to take her to shallow water and gently rub her bum. It keeps me up to date with how she is going and I check her hull for any problems at the same time.

What antifoul did you use? Had similar issue with my most recent application.

Same 60grit wet paper on a sanding float, after the gurnie, it's a good way to find any dodgey bits and create a good key

FabulousPhill said..
So, 4 months after applying expensive antifoul paint, you had someone rub the paint off?

Done correctly it's not a case of rubbing off paint. If that was the case my boat would be bare gel coat by now.

Has anyone here used an air-powered sander? Around Port Stephens there's nowhere you can dry-sand antifoul with an electric sander, I have a LOT of old hard racing antifoul to remove, and neither wet sanding by hand or a scraper do anything to it. The alternatives seem to be to pay thousands to get it professionally blasted, or get an air tool.

Local marina guy ( Pittwater } told me there's an invasive species of barnacle about and that's why there is such rapid re-growth.

Yep air sanders need a lot of air, even the little palm sander, though you would imagine most slipways would have a good compressor and the air tools are relatively cheap. It's a gruesome task no matter how you look at it. I'm assuming a glass hull so burning it off would have complications. I recently had the task of blasting a big aluminium cat with an industrial pressure washer with a ceramic tip it took old anti foul off, but maybe too savage, likewise the needle scaler, so perhaps the chemical paint stipper, but as I said gruesome!

I have applied antifouled to approximately 200 + Vessels including my own over the past 30 years. Not once I have wasted my time wet rubbing the old paint back and always laugh when I see yachties arrive on the slip rubbing down the hull with wet rub and changing there facial skin and arms colour to black or blue.

A good high pressure wash is all that is needed for prep . Some scarfing in with scraper and 80grit maybe required with a compatible high build primer and tie coats if the antifoul coatings are more than 10 years old and flaking ..

At the end of the day it's just a single pack paint very much like repainting your bathroom in your house, it's not a two pack where you need to remove the gloss .

Chris 249 said..
Has anyone here used an air-powered sander? Around Port Stephens there's nowhere you can dry-sand antifoul with an electric sander, I have a LOT of old hard racing antifoul to remove, and neither wet sanding by hand or a scraper do anything to it. The alternatives seem to be to pay thousands to get it professionally blasted, or get an air tool.

Can't do dry with a proper extractor on it?

stray said..

Chris 249 said..
Has anyone here used an air-powered sander? Around Port Stephens there's nowhere you can dry-sand antifoul with an electric sander, I have a LOT of old hard racing antifoul to remove, and neither wet sanding by hand or a scraper do anything to it. The alternatives seem to be to pay thousands to get it professionally blasted, or get an air tool.

Can't do dry with a proper extractor on it?

I'm fairly sure there's a blanket ban. Given the fact that many similar marinas don't let you do any work on your own boat, I don't want to push the situation.

Ramona said..

Chris 249 said..
Has anyone here used an air-powered sander? Around Port Stephens there's nowhere you can dry-sand antifoul with an electric sander, I have a LOT of old hard racing antifoul to remove, and neither wet sanding by hand or a scraper do anything to it. The alternatives seem to be to pay thousands to get it professionally blasted, or get an air tool.

I have one of these. www.tradetools.com/renegade-50mm-inline-sander-rtp501?pid=RTP501&utm_source=google&utm_medium=cpc&utm_campaign=free+listings&gclid=Cj0KCQjwspKUBhCvARIsAB2IYutEGPlzZgKnWAQ9ODqLFFOd8-8_sb_crzvpF5aQdTOyGzNtjLnPyLwaAqU8EALw_wcB

They work fine on dinghy hulls where you are working down but the compressor still slows you down. Not sure how you would go overhead but you could use wet and dry with a mate with a hose.

An alternative which I have used in the past and the trawler blokes do this. Save up the worn out 200mm sanding discs and mount them on 5" rubber pads on the mini grinder. Cut off the edge into a series of flats so you have a series of corners, about 8. Move the machine over the job and let the corners do the cutting.

Caution: This can be mildly dangerous depending on your skills!

Excellent, thanks. That's a lot better than the $5k or so they want to strip the whole thing back, as I recall it. I plan to start by doing the foils and the bow and gradually extend the sanded area.