Removing old antifoul paint.

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William_H

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I am just starting to try to debulk the a/f build up. I have used Jotun Seaguard Antifouling paint for many years.
Now many recommend a scraper to remove the build up. I have found various scrapers useless as they just skid over the paint surface. I imagine seaguard might be a hard a/f. Also I do not have that really big build up I have seen on other boats. So using wet sand paper seems the only option.
I have always done a lot of in water scrubbing so a/f lasts about 6 weeks before first scrub. I am fussy about a clean hull and fouling is fierce here with warm water and lots of strong sun. So usually by the time winter haul out comes much of the a/f is gone. However there is a build up at the water line about a brush width wide that I am determined to cut back.
Two ideas seem to work best at the moment. One is a sanding disc on a battery powered drill. The drill has 2 speed gear box (much recommended) so disc turn fairly slowly. I use course sand paper and spray the paint with water and dip the disc in a bucket of water. It takes the paint back and with a fair bit of blue mud everywhere. Biggest problem is the drill battery does not last long.
Second trick was that I had a sand paper belt for a belt sander. This proved really easy to hold in one hand inside the loop and easy to move around to a clean piece of sand paper. The paint rinses off easily. But my arm gets tired.
Fortunately I have the boat at home and about 3 months to do as much as I can of paint removal. But on the other hand the centre section of the hull is a devil to get under when on the trailer. Drop keel is not so hard as the hull itself.
olewill (just looking for sympathy)
 
My sympathy, it's a horrible job.
I dry scraped my UFO 31 a couple of years ago, using a combination Fosbide tungsten scraper and a sharp 1" wood chisel. I found that changing methods gave one set of muscles time to recover.
Wet sanding seemed to take forever and was hugely messy. Trying to contain the run off was impossible. A supply of the correct filters for the face mask essential.
BTW, your reference to winter haul out. Do you actually get a real winter?
 
It is a horrible job, but it sounds as if you are not doing it correctly if scrapers are not working for you. You need to get the angle of attack correct or it just wont work.
 
Olewill,

you could try ' antifouling stripper ' if it's available to you, they say to apply newspaper on it to avoid it dripping off - but I've always found it pretty feeble stuff, will need lots of applications and time.

I tried a belt sander on my a/f buildup and was surprised how ineffective it was; I always use self eroding antifoul but over the seasons it still leaves a hard buildup.

Whatever you do, it sounds like lots of hassle and hard work; you do indeed have my sympathy, the worst job in sailing !
 
Make the job relatively easy. Buy a Bosch power carver/scraper model PSE180e, It comes with a selection of blades including a 2" wide scraper blade, now this blade is like a wide chisel & will dig into your gelcoat if used as is. However if you grind the business end of the blade with a small square flat on the very end & round the corners very slightly it becomes the best antifoul removal tool you can buy. Our Sabre had very thick old antifoul & the job was done in a couple of weekends.
Several members of our club have since used them & swear by them.
 
I use a rotary 'Sanding Disc' on a drill also, and find that it's the most effective technique. I've got one that combines 2 soft abrasive discs, giving double the rubbing area, bought from a local DIY place. There are (at least) 2 types; one for removing paint from a car, which is of a far harder material, and the other for varnish removal, and such like.
The other vital thing is a REALLY good dust mask of course.
Then, retire and rehydrate with a few stubbies from the bottle-o etc.etc...!
 
Sanding mesh is the way forward, still hard work but massively easier than every other method short of sand blasting. Used to take 3/4 days to wet & dry our 38 ft hull, now takes 4 hours. Scraping is hard to get a good finish and at some point the corner will catch and damage the gel or epoxy coating. Dry sanding toxic antifoul is just plain nasty and not worth the risk to you or anyone who walks past no matter what precautions you take. It is also very expensive in sanding sheets. Dipping an electric sander in water I would not fancy doing and I doubt will be wet enough - you need a hose pouring water over the area every 2 minutes.

A 5 metre role of 60 grit sanding mesh from eBay will be enough for years. We use a Norton drywall hand sander (make sure you get the larger size to fit the mesh role width). £20 all in is the best investment we have made for the boat, picked up the tip from a post here (sorry can't find it now) but wish we had discovered this 10 years ago!

Ckris
 
There is a DIY antifoul remover / paint stripper using household ingredients. Various Mixes to your strength. Mostly based on Lime. I think google gives a few links to them.

Last year I was surprised about how much a powerful pressure washer took off. I did an area at a time with repeated wash 'n dry to loosen the stuff. Much the easiest system if it works on your boats old coatings.
 
Actually I'd suggest sand blasting. If you can get your hands on a Kaarcher pressure washer and buy the blasting kit it will do an excellent job. Without having the force of professional kit. it doesn't require such expertise to avoid doing damage. It works on an area around one inch diameter so a few passes will do the "brush width" strip. The sand needs to be kiln dried in UK, but you have a much drier climate. PPE required - eye protection, dust mask, gloves and full clothing or you'll exfoliate any exposed parts. I had such a smooth face for weeks it took years off me (literally). I found I could strip each coat of paint individually! Place a tarpaulin under the boat to catch the sand and the paint for disposal and because you will be very unpopular with the neighbours if they get to tread it into their homes, cars, etc.

Rob
 
There comes a time in life when you realise that you have worked hard and saved hard and a contractor with blasting kit is the way to remove old antifoul. I am as keen as the next man to DIY and save money but there are some jobs like antifoul removal or home decorating where its better to bite the bullet and pay someone.

Its what eastern european immigrants are there for!
 
Seajet said:
Olewill,

you could try ' antifouling stripper ' if it's available to you, they say to apply newspaper on it to avoid it dripping off - but I've always found it pretty feeble stuff, will need lots of applications and time.

I tried a belt sander on my a/f buildup and was surprised how ineffective it was; I always use self eroding antifoul but over the seasons it still leaves a hard buildup.

Whatever you do, it sounds like lots of hassle and hard work; you do indeed have my sympathy, the worst job in sailing !
Click to expand...

Tried the International Paint stripper stuff, about £75 worth. Took about a year for the tarmac driveway to recover despite using plastic sheeting. Oh and it only took one layer off at a time. If I ever have to do it again I will pay the man with the slurry blasting kit.

Pete
 
Keith 66 said:
Make the job relatively easy. Buy a Bosch power carver/scraper model PSE180e, It comes with a selection of blades including a 2" wide scraper blade, now this blade is like a wide chisel & will dig into your gelcoat if used as is. However if you grind the business end of the blade with a small square flat on the very end & round the corners very slightly it becomes the best antifoul removal tool you can buy. Our Sabre had very thick old antifoul & the job was done in a couple of weekends.
Several members of our club have since used them & swear by them.
Click to expand...
+1 Having used a hard anti foul for 10 years, The Bosch blades needed regular sharpening, Also used a Bahco scraper which worked better on the waterline which maybe because it was mainly out of the water was extra hard.
 
DanTribe said:
My sympathy, it's a horrible job.

BTW, your reference to winter haul out. Do you actually get a real winter?
Click to expand...
UK folks probably think of Oz as one climate zone and of course spanning 40 degrees of latitude has plenty of variations of weather. I am in Perth 32degrees south. Winter is clearly defined by shorter days 7am to 5.30 PM and colder. We don't however get frosts being near the sea min morning temps around 4 degrees and lowest max being around 17. We have winter racing at our club twice per month. Some days can be magnificent but typically not so much wind. All our rain comes in winter but never enough.
I pull the boat home for winter partly to enjoy the refurbishment but mostly because the water gets a bit too cold for my habit of in water scrubbing to keep bottom clean. This is the main part of a/f removal each year. Along with not putting much on. Thanks all for the sympathy re a/f removal. As usual I will do a bit then give up and paint over it all. olewill
 
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