Antifouling removal ideas!

[Akestor]

Hello!

Boat is out again, and the project is to remove all old antiful and go back to gelshield-gelcoat coating. I will then reapply new protection!
I ve read almost any method online, and i so far i have tried the following with miserable results.

1) orbital sander...this will take about a decade... sanding with a handsander is much faster that this...
2) i bought a SKILL electric scrapper. I thought that was going to do it, but either it does nothing ( small angle) or it digs into the gelcoat. ( i pasiently checked every angle, there is no sweet spot were it will remove just the paint..it digs or does nothing.

I cant afford sandblasting, its to much money for my pocket. I came up to this solution with the angle grinder and this tool on it. Any one has used this on fiberglass?
https://www.aliexpress.com/i/32854132620.html

 

[pvb]

You really shouldn't dry-sand antifouling!

 

[Akestor]

You really shouldn't dry-sand antifouling!

I read someone wetsanded with mesh but he doens't say if he removed to the gelcoat or just for applying a new layer on top of the old... I know it;s going to be small Chernobyl with dry sainding... but i am running out of options.

Paint remover is another way...but the marine remover is pretty expensive stuff...

 

[MoodySabre]

Google antifoul stripper. There are various makes.
Also http://www.ybw.com/forums/showthrea...r-which-one-is-best-for-realy-old-antifouling

 

[Graham376]

Took ours back to the epoxy this January, quite an easy job using Sandvik (or Bahco) two handed scraper with carbide blade (corners rounded to stop it digging in), followed by light dry sand with dust extraction. Primed with Jotun Vinyguard.

 

[sgr143]

If you can stand to do it by hand, this sort of tool works very well:
https://www.amazon.co.uk/Bahco-Carb...031_1_23?s=diy&ie=UTF8&qid=1557504742&sr=1-23
I used a cheaper version from screwfix that, they no longer seem to sell, to take all the antifoul off my boat 3 years ago; this one from B&Q is similar -
https://www.diy.com/departments/harris-38mm-wood-scraper/182460_BQ.prd
It took several days... but it was cheap!
Steve
[edit - looks like Graham 376 just got in first with this suggestion!]

 

[macd]

+1 another with Graham & sg for the Bahco-type scraper. Unless the old antifoul is particularly stubborn , this should work. Tougher bits may respond to softening with home-made stripper of caustic soda and wallpaper paste (skin and eye protection required, etc.)

 

[dunkelly]

i did this earlier this year , used a harris scraper ex screwfix and wait for it , wallpaper paste - with caustic soda mixed in from bq . i had about a dozen layers to remove and it took time but it worked . apply it quite thick, paste holds the caustic on so it can do its work . leave overnight then scrape - if you are lucky you may get two layers off at a time . its still painfull work but absolutely worth it . dont forget to take all safety precautions .

 

[Akestor]

Thank you all for your replies! Looks like hand scraper is the way to go...I read that polyester is sensitive to caustic soda, but theoriticaly it will never reach gelcoat. Even a litle bit it should not do harm.
Should i buy extra blades? do they worn out?

 

[duncan99210]

I removed about forty years worth of antifoul from my Hurley 18 this winter. Tried industrial strength stripper: that wound up softening the gel coat as well, so gave that up.... In the end a two handed pull scrapper was the only answer, as others have said. Took about ten hours or so to get rid of the old stuff, mostly in two hour sessions to prevent total back seizure. I found that the blades didn’t need replacing but the Hurley isn’t what you’d call a big boat.

 

[wipe_out]

We used the Proscraper from Force4 that connects to the hoover so there was little mess to deal with.. Then used an orbital sander with 80 grit paper also connected to the hoover to get through what was left and take us back to gelcoat..

 

[Mistroma]

Chemical strippers will soften the anti-foul and might work. However, most people don't seem too happy with it and if it turns to a sticky goo then it will be even more difficult to remove.

I think that the SKIL scraper uses the same blades as my old BOSCH power chisel. I have used that several times with success but only on brittle anti-foul. It does nothing on softer ant-foul but things like Cruiser UNO etc. flake off quite well. My dust mask ended up perfectly clean last time I used it and I swept up 2-3 bucket loads from the concrete. It tends to shatter into pieces with little dust.

It might be worth trying the SKIL again as long as your anti-foul isn't a soft type.

Tips
1) Don't bother with the flexible scraper blade, it never worked well
2) Reverse the widest chisel blade, blunt it slightly on a grinding wheel and try to find the best angle

I usually dig into the gel coat slightly 1-2 time before I get the hang of it. The tiny nicks are easily filled and remainder of the hull isn't damaged. I don't find it too tiring and think I did my 42' boat in a couple of days (with quite a few stops).

Short example video here:

 

[Graham376]

Thank you all for your replies! Looks like hand scraper is the way to go...I read that polyester is sensitive to caustic soda, but theoriticaly it will never reach gelcoat. Even a litle bit it should not do harm.
Should i buy extra blades? do they worn out?

The blades are double sided and I used two on a 38 ft hull, be careful not to buy the serrated ones. Previous time I did it with a Bosch power scraper but that was much slower and prone to digging in to the gel if not very careful. Thick dry antifoul comes off quite easily with the scraper, I took 9 years buildup off this time. Suspect softening it with chemicals could make it more difficult. Wear eye protection and mask, you may end up looking like a Smurf.

 

[anoccasionalyachtsman]

To the OP, and anyone else thinking of using these things from his link.

They are excellent paint strippers. And gelcoat, and laminate. Perfect for paint stripping on metal, but so vicious that you just can't get a delicate touch on softer stuff.

Yes, I bought a few, and yes, I have a little damage to repair, but they're going to very handy on the next-but-one car project.

 

[Homer J]

Hello!

Boat is out again, and the project is to remove all old antiful and go back to gelshield-gelcoat coating. I will then reapply new protection!
I ve read almost any method online, and i so far i have tried the following with miserable results.

1) orbital sander...this will take about a decade... sanding with a handsander is much faster that this...
2) i bought a SKILL electric scrapper. I thought that was going to do it, but either it does nothing ( small angle) or it digs into the gelcoat. ( i pasiently checked every angle, there is no sweet spot were it will remove just the paint..it digs or does nothing.

I cant afford sandblasting, its to much money for my pocket. I came up to this solution with the angle grinder and this tool on it. Any one has used this on fiberglass?
https://www.aliexpress.com/i/32854132620.html

I guess that this post identifies the ‘rub’ . I would be interested to hear the general opinion,especially since this is PBO and people do often do their own work. But We often hear about the decline in boating especially amongst the young - who are time short. No one wants to do the hard work on a boat (or has the time more importantly) but few can afford others to do it for them - especially the young.
So where do we go from here?

 

[DJE]

We used the Proscraper from Force4 that connects to the hoover so there was little mess to deal with.. Then used an orbital sander with 80 grit paper also connected to the hoover to get through what was left and take us back to gelcoat..

+1 To the two-handed vacuum scraper. Have some heavy-duty bin bags handy for emptying the Hoover into. I did took about 12 years worth off our 39 footer in 17 hours spread over 4 or 5 days. Virtually no mess on the ground.

 

[Sandy]

Having scrapped back my last boat by hand, you only ever do this once!

 

[guernseyman]

When I come out and the hull is pressure water washed it seems to do a pretty good job of removing any crud, and the antifouling as well, dammit.

 

[keithb]

As Mistroma, I used 2nd hand Bosch power chisel, blade exactly as he advises, chipped off all old antifouling in about 1/2 day (Southerly 100), went really well. International micron2 etc, did it same day boat lifted out for winter. Then sanded to finish.

 

[Graham376]

To the OP, and anyone else thinking of using these things from his link.

Durable-Poly-Strip-Disc-WheelThey are excellent paint strippers. And gelcoat, and laminate. Perfect for paint stripping on metal, but so vicious that you just can't get a delicate touch on softer stuff.

Much too vicious unless you want to fill and fair. Mate used a similar one and it left lots of half moon indentations. Fortunately, very thick 1970s hull so he spent many hours afterwards sanding smooth.

Yes, I bought a few, and yes, I have a little damage to repair, but they're going to very handy on the next-but-one car project.