As there has been some questions on antifoul removal/ barrier coat I'll start this topic rather than answer on the 'love your boat' thread.
I plan to remove the antifoul using a two handed tungsten blade pull scraper, here's the link;
m.masters.com.au/
I've tried it on painted timber and it stripped back very easily, time will tell how good it is on the antifoul.
I've got 4 blades which are double sided which I've rounded the corners to avoid damage to the hull. The blades are only $7.50 each so I'll get more if required.
Once I've got the majority of the antifoul off I will wet sand the remainder using 60-80 grit cloth backed sand paper (I think the cloth back will perform better than standard wet and dry). m.masters.com.au/
If I have trouble with the sand paper clogging I will use 100 grit open mesh screen here's the link
m.masters.com.au/
I also have two sheets of double sided 60 grit heavy duty open mesh which I think will work well wet sanding. Unfortunately they don't make it any more.
I've allowed 3 days to remove the antifoul and 3 days to apply the barrier coat and antifoul.
I had plan to use Soda Blast but the marina won't allow any type of blasting in the hard stand area, I did get a quote of $2,000 to do a 10m yacht.
I'll report back in late February
Select to expand quoteseabird said..
I had plan to use Soda Blast but the marina won't allow any type of blasting in the hard stand area, I did get a quote of $2,000 to do a 10m yacht.
"Never, ever let a boatyard staff convince you to sandblast, sodablast or shotblast with any medium to remove paint from your hull - unless the hull is
steel." Don Casey, This Old Boat, p. 432. So Don cautions against it, however I think since you are working to a short schedule, that it would remove
the risk of not being able to accomplish the task in such a short timeframe if you could find another marina that would allow it to be soda blasted.
If the anti fouling is well stuck, then it might be possible to cross hatch it with a wavy blade on a pull scraper. If it requires such heavy scraping though
then it might take 20 blades.
I think it would require sanding after the scraping. Or maybe it could just be sanded if it is so well stuck that it is difficult to remove with scraping.
I couldn't imagine sanding it by hand. To wet sand it with a sander would require using an air sander and a huge compressor that could keep up with
the air sander. Or if the marina allowed it, to power sand it using a dust extractor.
Some more quotes from Don Casey:
"With the arms of a weight lifter and the stamina of a marathoner, you could use a disk sander to quickly convert multiple layers of bottom paint into a
colourful cloud of toxic dust - with you in the middle."
"There is simply no nastier boat job than stripping the bottom, so avoid it if you can."
I stripped an Adams 10 a number of years ago using a Sandvic scraper which is similar to the one you are going to use and sand paper. I would have to say it was the worst week (not 2 days) of our lives for myself and a couple of my crew. Find a marina that allows Soda blasting and pay the $2,000.00, you will not regret it. The end result was good but never again.
I used a similar scraper to do my hull then sanded it till all the anti foul was removed not quiet finished yet.
I still have to fair it back and fill some old sea cock holes. I bought some International Inter protec two pack barrier coat. Ill do at least 4 coats
I rounded the edges on the scraper blade.I had four blades only used one its not sharp now but Ill sand whats left.
Just used 80 and 120 grit
I have a few gouges to fill 
not to bad better than spending $2000 blasting. which will be spent on masts and rigging instead
On another note Teak Rub Rail
Been thinking about using west system 207 after prepping my teak rub rail then I will apply varnish to give it UV protection.
So hoping in doing this I would not have to sand back to bare teak every time saving the wood from thinning just re-varnish back to the epoxy.
I tried to do it with Bote coat epoxy but it went cloudy early last year. The west system 207 is suppose to be for this purpose
I have done that job once a couple of years back . did it alone . i think it took me around 50 hrs solid scraping over a few weeks . then a final sand with dust extraction. 5 coats epoxy and then anti
the comments from Jode , keensailor and someday are spot on !!!!!
its a killer !!! never again !!
soda blast or paint stripper would be preferable , but even the paint stripper method looks bad ! seen that done twice .
DONT TRY AND SAND IT OFF IT WILL DESTROY YOU !!!!!
Another way to do it dry is with a power planer set to minimal cut depth.
I used a cheap Ozito planer with double sided blades on an S&S 34 I previously owned.
What comes off is not as fine as sanding dust but use of a respirator mask is still mandatory.
Select to expand quoteSandS said..
I have done that job once a couple of years back . did it alone . i think it took me around 50 hrs solid scraping over a few weeks . then a final sand with dust extraction. 5 coats epoxy and then anti
the comments from Jode , keensailor and someday are spot on !!!!!
its a killer !!! never again !!
soda blast or paint stripper would be preferable , but even the paint stripper method looks bad ! seen that done twice .
DONT TRY AND SAND IT OFF IT WILL DESTROY YOU !!!!!
SandS what type of scraper did you use ?
Was it the two handed pull type or the normal push style scraper
I was very impressed by the way the pull scraper cut through the paint in the trial I did. It worked like a hand plane and 'cut' the paint off rather than trying to lift it off like a push scraper does.Select to expand quotecisco said..
Another way to do it dry is with a power planer set to minimal cut depth.
I used a cheap Ozito planer with double sided blades on an S&S 34 I previously owned.
What comes off is not as fine as sanding dust but use of a respirator mask is still mandatory.
I did look at the power planner but I thought the risk of damaging the gelcoat /hull was too high
.
I think my scraper was a barco
I ds buy a cheap elctric scraper off masters could not gind the blade as i bought it acouple of years ago along with the barco scraper whoch worked really well
seabird , i started of with propriety scrapers purchased from various places. push pull vibrating electric you name it i had it it bristling out of the toolbox and my ass !!! . These worked well on the first location . [ the bit that was almost falling off ! ]
The fact that some was starting to crack and come loose is the reason i decided to do the job in the first place .
After removing the first 1 and 1/2 square mtrs on side one , it got harder to get off !! it was still stuck ! a bit like shiiiitttt to a blanket !!
But me being, stupid !!! didn't want to give up !!!! so i kept going for the rest of the day , following fault lines .
Before I came back to attack !! on day two I fabricated a two handed push scraper with a handle about three foot long and a hand plane blade bolted to the end of it . It worked a treat . I found that if it was too sharp it was no good . It was better with a very slight bevel on the reverse [flat] side of the blade , that was facing the hull. ......... it was still a struggle some of that paint was still very well STUCK ON THE BOAT !!!!
Now HG, don't start yelling at me !!! I saw from your photos that you were having no problems , so my intervention was not needed !! I could tell from here that your paint was FALLING OFF !!!! I know you were pleading for help, but i think you were just being lazy !! 
So i thought it best to let you SCRAPE YOUR OWN BOAT . I mean, I had sleeping , eating and surfing to do !!! 
I took all the antifoam off my tri (yes three hulls) by wet sanding with 80 grit and finishing with 120. All with an Aldi compressor and random orbital. Used an old spray gun to keep things wet. I lost track of the time, but it seemed for ever. Glad its gone though. One hint: don't do it in winter, you will get wet and cold. Trust me.
Just some feedback on my attempt to completely remove antifoul with a two hand pull scraper, as detailed in the first post.
Well I quickly realised that it was not achievable in my allowance of 3 days. The scarper removed the top soft layer but struggled with the harder lower layers.
Given the majority of antifoul was in good condition I just did a light wet sand and apply two new coats of Mircon Extra, happy with the end result.
The clean bum certainly has made a difference to boat speed.
As others have suggested it appears the only realistic method of undertaking a complete removal is via blasting.
I've got 18 months to plan for that at my next lift out.
If anybody needs 8lts of epoxy primer (Interprotect) or 4lts of black International Ultra antifoul (both unopened) happy to sell at a discount to retail.
In my picture library there are pics of a major antifoul removing operation back in 13 at Scarborough Qld. It is a Savage 42 Oceanic, with badly laid fibreglass full of osmosis, typical of the mid seventies.
I was helping a friend. My mate rejected the idea of blasting on cost basis. He later on regretted it after standing on the hard for two months.
We started with a grinder and sander than scraping it with all kinds of metal scrapers, blades who knows what, we tried all. The best find was a w o o d c h i s e l ! Inch or two wide. The accumulated hard antifoul was 4-6mm thick in most places impossible to remove with a grinder. Scratching the gelcoat was no issue as it had to be redone anyway. We used to call ourselves the 'blue boys' beeing covered head to toe in blue antifoul. Eventually we done it, cutting out
most of the osmosis and redoing the hull with International and ablative antifoul.
Here l have to praise the rep from International, who came out three times to see how we progressed giving advise and drink the xxxx gold we were provided. No wonder the job took two months to finish!
With hindsight, l would do it again though it was a dog of a job, but learned a lot and lived in a marina for free, on my own yacht sailing it on weekends.
Select to expand quoteseabird said...
Just some feedback on my attempt to completely remove antifoul with a two hand pull scraper, as detailed in the first post.
Well I quickly realised that it was not achievable in my allowance of 3 days. The scarper removed the top soft layer but struggled with the harder lower layers.
Given the majority of antifoul was in good condition I just did a light wet sand and apply two new coats of Mircon Extra, happy with the end result.
The clean bum certainly has made a difference to boat speed.
As others have suggested it appears the only realistic method of undertaking a complete removal is via blasting.
I've got 18 months to plan for that at my next lift out.
If anybody needs 8lts of epoxy primer (Interprotect) or 4lts of black International Ultra antifoul (both unopened) happy to sell at a discount to retail.
Silkies up your way she may want some barrier cote
If you were closer I'd be interested in some more barrier coat
Good decision Seabird the end result wouldn't have been much different if at all if you had scraped it all off
I'm only doing this time as I'm in no hurry .I don't want to be doing it when I'm retired 65 next January. Id like to have my old boat finished by the end of the year.
Then just do yearly maintenance after that. In saying that a a short breeze went through my head visualizing Cisco and B.O.A.T 
I wish he had not told me that one
