New to anti-fouling - help please !

[ericw]

Can anybody out there offer me some advice on that beloved subject of anti-fouling ??!!

Never having anti-fouled a hull before I would like to know what the procedure actually is ! I guess the old anti-fouling has to be sanded down first in order to give a decent surface for the new paint to adhere to ? What method is best - do u use an electric sander or is it a case of a bit of elbow grease ? What grade of paper works best ?

By the way, the hull underwent a complete epoxy treatment last winter, so the current anti-foul layer won't have lots of old layers beneath !!

Any help will be gratefully received ...... Regards.......Eric.

 

[Guest]

I just use the cheap stuff as all that is needed is a key to sound material. You will find it will soon clog so you will need plenty, then I use cheap wool type rollers so they can be discarded after use. I would probably take a diferent view if I wanted a finish for racing but for cruising the los in performance is negligable.

<P ID="edit"><FONT SIZE=-1>Edited by harrygreasley on 09/10/2002 11:48 (server time).</FONT></P>

 

[JerryHawkins]

Don\'t sand it...

You shouldn't need to sand it. Just give it a thorough wash with a 'pressure washer', let it dry and re-coat with your new paint. This certainly the case with Blakes Titan Ultra, but check with the paint manufacturer you're using. If you do need to sand then use wet&dry paper 'very' wet to avoid any dust which is toxic!

Cheers,

Jerry

 

[miket]

Dry sanding is also very anti-social to your nieghbours.
Dust everywhere.

 

[dickh]

Don\'t sand it!

Don't sand it - it almost certainly won't need it if it the previous coating has adhered properly. Just make sure it is clean and just paint over it.

dickh
I'd rather be sailing...

 

[qsiv]

Let's assume you arent racing ...

Be exceedingly careful taking sandpaper anywhere near antifoul - the dust is easily inhaled and is highly,highly toxic. If you do need to sand - use wet and dry WET - and avoid the slurry.

Try and establish what was used before, and if it worked and is still legal then I would uggest using the same again.

Pressure washing (with a goof scrub on the stubborn bits) is usually all the preparation that you need. Whether you need one or two coats will depend on the fouling tendencies of the area you spend most time in. I like to put an extra coat around the waterline as I prone to scrubbing that area periodically from the dinghy or pontoon.

Dont cover the log or echosounder (or earting plate for an MF), and dont paint the anodes or sterngear.

Read the instructions on the chosen antifould and work be aware how quickly it needs to be re-immersed - each type can be different.

Oh - and you will probably have just found a good use for an old pair of oilies and boots. If your as blind as me and wear specs - then use an old pair as they will get spattered. Glass ones are better than plastic 'cos the paint scrapes off withouth scratching!

While you're under the boat take a good look at the bist you dont normally get to see - rudder hangings/bearings/gudgeons and sterngear.

 

[Miker]

Keep the water intake clear

This might seem obvious but the build up of antifouling over the years can clog up the grill over the engine raw water cooling inlet and cause the engine to overheat. I found this out to my cost last year. Fortunately no harm was done apart from a shredded impellor.

 

[chas]

And put an extra coat on areas of high "wear"or turbulence - leading edge of fin and skeg, rudder, p bracket etc.

 

[verytricky]

Unless the new anti fouling paint is badly cracked, you can put another layer ontop of the old. Do not sand. the dust is toxic. You can use an anti foul remover paint, and a high pressure washer if you feel you have to remove it all.

 

[VMALLOWS]

Without any doubt (IMHO) if it was only epoxied last year, you don't want to disturb the anti-foul any more than necessary to remove the slime/barnacles etc. (I woulndn't expect that much?). A thick nylon scourer (the ones about 9"x4") work well. I would hope that an initial coat of antifoul was applied as a 'key' coat to the epoxy before it fully cured, or alternatively the whole hull was roughened before the first coat applied, otherwise the first coat might not adhere to the epoxy, and peel off (along with all the later ones!).

I epoxied my hull from new, and have not 'scraped-off' in 19 years........just scrub /wash with fresh water/repaint. Still hard enough work!

 

[rogerroger]

The best way is to con a couple of mates into helping and make a day of it with a crate of beer.

I had 2 volunteers last year and we (wet) sanded down a little to get rid of the crap that doesn't come off with the spray washer and got 2 coats on (just) by dusk.

Do take heed about the toxic nature of anti foul. Cover up and get a respirator rather than a simple paper face mask - only about a tenner from screwfix.com

Oh - and don't even attempt to clean the paint roller at the end of the day! Trust me, with my red AF my kitchen looked like I'd murdered someone after about 2 mins and the roller wasn't even remotely clean. Chuck it.

/forums/images/icons/cool.gif Roger Holden /forums/images/icons/cool.gif
<A target="_blank" HREF=http://www.first-magnitude.co.uk>First Magnitude</A>

 

[Grehan]

Nota bene

Remove your speed log and its impellor thingy (and any other delicate hull fittings) before pressure washing.