Scraping of Boat feedback

[Safeseas]

Hi, I would appreciate some help with regards to our presently ongoing project. We had bought Jeanneau Sun Odyssey 33 feet sailboat last year and this year we planned to take to the yard for full removal of all layers of antifouling and re painting as necessary. We have scraped most of the layers using paint remover ( gel substance - svernicatore forte) and scraping but the last layer ( seems to be some kind of barrier / gel shield ) did not go off completely but partially as seen in attached photos. We did not see any signs of blisters but we’ll have it also checked for moisture/osmosis. I wanted some help/opinion, in the eventuality that no moisture / osmosis exists, shall we sand as applicable ( leaving part of the existing paint ) and then apply new barrier coat + Anti fouling. Any suggestions appreciated. Also the keel could be scraped completely, what is the procedure on that since it has some minor signs of rust .Thanks alot

 

[Tranona]

Fill and fair to a good clean surface then underwater primer such as Jotun Vinyguard or International Primocon and antifoul. You could epoxy but to be really effective you would have to get the surface blasted back to clean GRP. Much the same with the keel. If you can get it blasted then it is worth using epoxy, otherwise grind the rust off and prime.

 

[Safeseas]

Fill and fair to a good clean surface then underwater primer such as Jotun Vinyguard or International Primocon and antifoul. You could epoxy but to be really effective you would have to get the surface blasted back to clean GRP. Much the same with the keel. If you can get it blasted then it is worth using epoxy, otherwise grind the rust off and prime.

Thanks Tranona, much appreciated, we do not wish to surface blast, however your reply was encouraging as we were thinking we did something wrong being our first time...thanks

 

[Safeseas]

Other views/opinions welcome...thanks again

 

[DFL1010]

Really should have a sheet down to catch the antifouling that comes off the boat.

Not great for the lungs (either yours or others working on their boats around you), and pretty nasty stuff to leave in the general environment.

 

[Safeseas]

Really should have a sheet down to catch the antifouling that comes off the boat.

Not great for the lungs (either yours or others working on their boats around you), and pretty nasty stuff to leave in the general environment.

The antifouling removal was carried out with a pasty antifouling removal and all residue cleaned off, no dust particles where airborne as till this level no sanding was carried out, just scraping off the paint remover...with some considerable effort

 

[Caer Urfa]

Agree with others do it once and do it right and have the hull sandblasted, then 5 x coats of International Gelshield 200 (or Jotun Penguard HB ), 1 x coat Primocon, 2 x coats antifoul and the hull will last for ages.

We did one also scrapped by hand and had a problem with the old osmosis primer but did get it off using an orbital sander with 40 grit then 120 finish as you need a good contact surface.

Any metal should be wire brushed back to bare metal then 5 coats of primer then two coats of antifoul

Have fun

 

[DFL1010]

The antifouling removal was carried out with a pasty antifouling removal and all residue cleaned off, no dust particles where airborne as till this level no sanding was carried out, just scraping off the paint remover...with some considerable effort

Seems to be making a bit of a mess of the floor then if you're catching it all.

 

[LadyInBed]

and scraping but the last layer ( seems to be some kind of barrier / gel shield )

Yes, probably a primer.

 

[Safeseas]

Yes, probably a primer.

Thanks for reply...Do you think if I sand down alike this photo 55 by hand I can then re apply new coats or I ll have to go down till gelcoat beforehand

 

[dankilb]

Thanks for reply...Do you think if I sand down alike this photo 55 by hand I can then re apply new coats or I ll have to go down till gelcoat beforehand

The ‘below the waterline’ primers previously mentioned (my vote is for Vinyguard) are fantastically tolerant of an imperfect substrate and offer an ideal prep for antifoul. They’re literally designed for your stage/requirement/application.

So, while going back to gel can offer advantages (we did this in order to epoxy barrier coat), there’s no need to and an appropriate primer will set you up perfectly for new antifoul and readiness for sailing.

 

[Safeseas]

The ‘below the waterline’ primers previously mentioned (my vote is for Vinyguard) are fantastically tolerant of an imperfect substrate and offer an ideal prep for antifoul. They’re literally designed for your stage/requirement/application.

So, while going back to gel can offer advantages (we did this in order to epoxy barrier coat), there’s no need to and an appropriate primer will set you up perfectly for new antifoul and readiness for sailing.

Thanks a lot for reply..much encouraging...we will sand the existing shield that has imperfections and apply primer etc as per your suggestions ..thanks