DIY Antifoul Process…

[BobbyD]

Hi There,

Sorry in advance for the basic questions but I have my recently purchased boat (Beneteau 281) lifted and looking to renew the anti-foul. The boat yard is fully booked for some weeks so I may need to attempt this myself for the first time as I am under some time pressure - there’s a lot of info out there but not 100% sure how to proceed

The survey noted that the hull is in general good state with some minor blistering to the keel. It is unclear what Antifoul was previously used but the survey did note that it was non-eroding finish. The existing anti foul is also in fairly good condition.

1. Where there is small blistering on the keel, should this just be removed with a scraper until the antifoul becomes more stable/bonded to the surface. This is then painted with a primer (any underwater primer?). Some advice seems to recommend epoxy primer?
2. Given the original antifoul is unknown, should it be fully covered with primer first or can a hard antifoul be applied on top?
3. If I were to leave the anti-foul in existing condition (with slight blistering to the keel) until winter when the boat gets lifted for a prolonged period of time, what are the implications (other than perhaps slowing the boat down)? Are there any long term effects to the hull?

Any advice greatly appreciated!

Thanks

 

[vyv_cox]

1. Is this an iron keel or a grp one? With grp you need some expert advice before scraping away.
2. I have used countless different antifoul paints on top of previous ones, never used a primer and never seen signs of flaking.
3. You will not notice any reduction in speed. This is probably your best action. Consult with somebody who can give you good advice at leisure. Even if it is osmosis there will be no significant worsening in one season.

 

[BobbyD]

thank you for the feedback. I believe it’s Iron keel (fin keel with bulb) but cannot find any reference to be sure. Is there an obvious way to confirm?

 

[Andrew_Trayfoot]

thank you for the feedback. I believe it’s Iron keel (fin keel with bulb) but cannot find any reference to be sure. Is there an obvious way to confirm?

Remove a bit of the antifouling and see if you get back to metal or gel coat.

 

[Andrew_Trayfoot]

Either way. Just remove any blistered and slap a couple of coats of AF over the top of what is there.
You can spend anything from £50 ish a tin to £100 plus.
My advice is ask around the boat yard and find out which brand works best locally.

 

[Neeves]

As suggested.

Have the hull pressure washed. Put on your preferred antifoam and go sailing. The more you pay, in general and the thicker the AF coat, the more effective it will be. I don't know how long your season is - but most, even cheap AF should last till the end of your Autumn as long as you give the hull 2 decent coats, roller.

Forget the blisters on the keel - do them when you lift in the winter. If you do them now you could lose weeks of sailing if it starts to get wet and you are advised to add an epoxy coat.

But - Don't panic!

I'd start a new thread for your prop - but Velox seems popular. You need to decide on this now as you will do hull and prop together.

Jonathan

 

[Spirit (of Glenans)]

First go over the entire underwater area with a scraper, to remove the remains of any aquatic organisms not removed by the power washer, and to remove any loose antifouling. Then wet-sand all over with 80-grade Wetordry sandpaper, (on a cork sanding block). If your scraper has revealed any flaky areas, sand back to sound paint and feather the edges. Some people favour mesh sanding media, such as Abranet.
Having consulted locals as to the most suitable brand of A/F for local conditions, and bought a suitable quantity, you are almost ready to apply it, but, it may not be compatible with the brand used by the previous owner. If you don't know what's on there then the best plan is to apply a tie-coat of underwater primer, such as International Primocon, or Jotun Vinygard the first time you tackle the job. In any event, if you have scraped away flaky
paint, back to the substrate, you will need to patch with primer anyhow. International's website has a handy tool for working out the quantities of paint required to cover various types and sizes of hulls.
Rust on iron keels is a subject in itself, but briefly, remove rust scale with a wire brush, either manual, drill- , or grinder- powered, apply a rust converter followed by the primer of your choice, and antifouling. You will have to repeat this process annually.
Stir your antifouling really well before application. Use a roller and tray. The most suitable roller sleeves are the ones meant for solvent-based (gloss) paint. The ones for emulsion break up fairly quickly. There are various schools of thought as to the size of roller; - a 9 inch will cover the area faster, but will begin to feel heavy after a while. A 4 inch will be less strain on the arm but will cause the job to take longer. A long-handled radiator roller is favoured by some and is especially useful for bilge-keelers. You will need masking tape for your waterline, use the green one, which is easier to remove, unlike the ordinary, cheap type, which will stick like s#!+ if it gets wet, or is left on for longer than the paint takes to dry. You will need a brush, preferably 2 inch, for cutting-in edges etc. Don't antifoul over skinfittings or transducers.
Enjoy!

 

[William_H]

OP mentions non eroding antifoul paint now on the boat. There may be a case for relaunch the boat and go sailing until next winter haul out. Rust bubbles on the keel can be ignored or treated as described. ol'will

 

[MoodySabre]

Put a carrier bag over the roller tray and pour the Af on that. At the end put the roller, the tape and your gloves on the tray, turn the bag inside out and chuck. Clean tray for next time.

 

[Chiara’s slave]

OP mentions non eroding antifoul paint now on the boat. There may be a case for relaunch the boat and go sailing until next winter haul out. Rust bubbles on the keel can be ignored or treated as described. ol'will

As he doesn’t seem overly concerned about performance, this might be the best plan. Maybefind a yard with a well priced offer of a lift, jetwash, and relaunch, around August time.

 

[john_morris_uk]

First go over the entire underwater area with a scraper, to remove the remains of any aquatic organisms not removed by the power washer, and to remove any loose antifouling. Then wet-sand all over with 80-grade Wetordry sandpaper, (on a cork sanding block). If your scraper has revealed any flaky areas, sand back to sound paint and feather the edges. Some people favour mesh sanding media, such as Abranet.
Having consulted locals as to the most suitable brand of A/F for local conditions, and bought a suitable quantity, you are almost ready to apply it, but, it may not be compatible with the brand used by the previous owner. If you don't know what's on there then the best plan is to apply a tie-coat of underwater primer, such as International Primocon, or Jotun Vinygard the first time you tackle the job. In any event, if you have scraped away flaky
paint, back to the substrate, you will need to patch with primer anyhow. International's website has a handy tool for working out the quantities of paint required to cover various types and sizes of hulls.
Rust on iron keels is a subject in itself, but briefly, remove rust scale with a wire brush, either manual, drill- , or grinder- powered, apply a rust converter followed by the primer of your choice, and antifouling. You will have to repeat this process annually.
Stir your antifouling really well before application. Use a roller and tray. The most suitable roller sleeves are the ones meant for solvent-based (gloss) paint. The ones for emulsion break up fairly quickly. There are various schools of thought as to the size of roller; - a 9 inch will cover the area faster, but will begin to feel heavy after a while. A 4 inch will be less strain on the arm but will cause the job to take longer. A long-handled radiator roller is favoured by some and is especially useful for bilge-keelers. You will need masking tape for your waterline, use the green one, which is easier to remove, unlike the ordinary, cheap type, which will stick like s#!+ if it gets wet, or is left on for longer than the paint takes to dry. You will need a brush, preferably 2 inch, for cutting-in edges etc. Don't antifoul over skinfittings or transducers.
Enjoy!

That would be a 'proper job' except.

It doesn't have to be green masking tape and we use blue low tack masking tape. Just make sure its the low tack and removable one and not the white/cream cheap stuff. If you are doing the water line (and where else will you mask?) then stick the end down and using several metres at a time and while holding it reasonably tightly, stretch it round the waterline. You'll get a much straighter edge. (Sorry if I'm teaching granny to suck eggs but I've watched people doing a few inches at a time and getting a very zig zag water line.)

I've always painted straight over transducers and skin fittings and never had a problem. I don't clog up the paddle wheel of the log with A/F though...

 

[BobbyD]

Many thanks for the useful replies and advice (as always!). The hull appears clean after jet wash and antifoul isn’t in too bad condition so perhaps the best course of action is to wait until winter once the boat is lifted for a prolonged period as suggested. I will take another look at it once down on the weekend and talk to the yard as suggested.

I’ve also reached out to the broker to find out what was previously used.

Again, thanks for the advice.

 

[Chiara’s slave]

Many thanks for the useful replies and advice (as always!). The hull appears clean after jet wash and antifoul isn’t in too bad condition so perhaps the best course of action is to wait until winter once the boat is lifted for a prolonged period as suggested. I will take another look at it once down on the weekend and talk to the yard as suggested.

I’ve also reached out to the broker to find out what was previously used.

Again, thanks for the advice.

Stick her back in and go sailing. The worst that can happen is she grows a beard. A lift and scrub will cost no more than the antifouling you’d put on, just do a proper job in the winter/spring, including dealing with the blisters. They can have 3 months to dry out that way.

 

[vyv_cox]

Put a carrier bag over the roller tray and pour the Af on that. At the end put the roller, the tape and your gloves on the tray, turn the bag inside out and chuck. Clean tray for next time.

On the only occasion that we had the yard apply our antifouling the man who did it did not even use a roller tray. He put a plastic bag in a rectangular paint bucket and tipped the can into that .

 

[Stemar]

Just one thought: You mentioned using hard antifoul. That tends to be used for faster boats, especially those used for racing but, from what I've seen, it's even less effective than eroding AF, so you'll be scrubbing off regularly. One club member who's a keen racer seems to do his boat about once a month. OK if you can DIY, but expensive if you have to pay for a lift. I won't say don't use it, but I'd consider whether it's the best for you in your situation. Personally, I'd use eroding AF, applied as suggested above - wash off, slap a couple of coats on and go sailing. Don't worry about the blisters, you can deal with them during a winter haul out.

 

[Chiara’s slave]

Once a month scrub/ clean off puts you at the back of the fleet. Before every race is the norm for us. You really wouldnt worry for a cruise though.

 

[Spirit (of Glenans)]

On the only occasion that we had the yard apply our antifouling the man who did it did not even use a roller tray. He put a plastic bag in a rectangular paint bucket and tipped the can into that .

A rectangular paint bucket is much better for a job that will use a large quantity of paint and will not be likely to spill when you are holding it one hand and not keeping your eye on it?.
B&Q sell them with an optional plastic liner which I've used for an exterior emulsion job.

 

[Neeves]

Once a month scrub/ clean off puts you at the back of the fleet. Before every race is the norm for us. You really wouldnt worry for a cruise though.

If you are racing and serious - dry sail.

Forget AF. polish the hull and lift after every race.

Admittedly ours was only 10m but it cost the same for a slip as store on the hard.

Jonathan

 

[Chiara’s slave]

If you are racing and serious - dry sail.

Forget AF. polish the hull and lift after every race.

Admittedly ours was only 10m but it cost the same for a slip as store on the hard.

Jonathan

100%. But not in the XOD class, which has to be permanently afloat in season, laid down in the class rules.

 

[Neeves]

100%. But not in the XOD class, which has to be permanently afloat in season, laid down in the class rules.

Not entirely unusual.

I recall in HK, Etchells are raced dry (as they are here) but here they also have a series for wet Etchells. I crewed on a wet Etchells for a short time.

We sail 365 so its a long season. I'm not sure if they have a day off, when you can dry sail - on Leap Years

I've lost touch with most of these oddities. Cruising yachts do not make good racing yachts.

Jonathan