Tools for mechanically removing anti-fouling from GRP.
There will be further blogs covering chemicals, safety, removal from metals etc.
From previous experience, my favourite tool is the ‘Pro Scraper‘ made by Gelplane International. It can be fitted to a normal or wet/dry vacuum. Whilst scraping the hull the dust and removed material that is generated is sucked straight into the collection bag/cylinder for easy disposal. The tool is comfortable to use and uses a hardened tungsten blade and has spares available.
I do find the mouth clogs easily when removing anti-fouling softened by paint strippers / anti-fouling removers.
I would also recommend grinding the corners of the blade to prevent gouging to the GRP hull.
My second favourite tool; I find it does a better job than the ‘Pro Scraper’ as pressure can be applied to the knob with one hand as the tool is drawn back with the other. The advantage it does not have is the dust extraction facility which helps to keep the horrible bits of blue anti-fouling going up your sleeve, in your hair, mouth, other nooks and crannies etc.
The blades are carbide edged and are replaceable; as with the ‘Pro Scraper’ I recommend grinding off the corners of any new blades to prevent gouging the item you are working on.
Electronic Chisels / Scrapers
Bosch made an electronic scraper the ‘PSE 180E’ which sadly is now discontinued. It has good reviews by users on the popular boating forums. I keep a search open on eBay looking for one and will report back once I have the chance to test it.
I found a similar device from a UK discount supermarket made by Park Tools. I have used it on a previous project and found it to work quickly on old dried anti-foul but it was extremely noisy and took a bit of practice to get the angle right. The blunt blade of the tool hammers at the paint and chips it off. I have not tried it on softened anti-fouling.
Some boat owners use electric sanders to remove the anti-fouling. This method generates a lot of toxic dust and quickly uses up sanding disks; they will not work on wet/soft paint as they will very quickly clog. Random Orbital Sanders (RO Sanders) using a random orbital pattern to avoid swirl marks. They should not be used near edges or corners where they will very quickly cut through the gel-coat and into the fibreglass layup.
The use of sanders may be better used to finish off the process of removing the anti-fouling to prepare the hull for its new anti-fouling / barrier coats.
I would not even consider using hand sanding for removing the bulk of the anti-foul. It would take an age and there would be nothing left of my hands or fingers!
Flexible sanding planes are useful for sanding large curved areas of the hull once the hull is ready for finishing. Other boat owners report using sanding sheets on poles as used by plasterers to extend their reach whilst sanding.
Soda blasting is becoming a popular method of removing anti-fouling from boat hulls. It uses a fine powder of various formulas where the main ingredient is Bicarbonate of Soda. The soda is blasted under high pressure compressed air at the hull where it then explodes upon contact with the hull/paint, the energy released blasts the paint from the substrate without damaging it.
The equipment used is mostly aimed at professionals though some DIY equipment does exist. Keeping moisture out of the blasting system to prevent it from clogging, and being able to provide enough compressed air are the main problems.
The process is very quick when using professional equipment but it does generate a lot of dust, and the blasting media is not reusable.
Anti-foul removal can be hazardous. Please seek advice from professionals/manufacturers for the appropriate safety measures to be taken, and methods of disposal.