[billy b]

Didn't anti foul the stern drive last year. Covered in large white barnacles when it came out of the sea. Any tips for gettting them off. Been told ther only answer is a scraper.

Thanks

billyb

[mikeyt]

You are in a tough spot. Barnacle heads have to be removed by scraping or sanding and a small angular head rotary sander is the tool for the job. Don't try this with sanding disk attached an electric drill or a regular sander. Removal of the heads must be precisely done, damaging as little of the undamaged paint as possible.
If the paint is already damaged but not extensively, the thing to do is use a medium grit such as 150 and sand all corroded areas down to bare metal. If there are pits, use something like a Dremmel tool with rounded grinding bit to remove the corrosion by products from the craters. If you don't do this, your efforts will fail. It is imperative that all corrosive oxides be removed before you attempt to repaint the outdrive. And yes, you will likely have to repaint the outdrive then apply the anti-fouling over that once done.

Just as a follow up to this i did a little reading. Apparently there are a couple of products on the market that help in softening the barnacles & their grip. I've cut & pasted this from another site: Algex is most effective at removing algae and slime and softening the shells and adhesive rings of barnacles. It is safe to use on metal such as the aluminum drives and props and stainless steel, if your props are stainless. It will not attack rubber or neoprene, which is what I assume your bellows and seals are made of. If the growth is particularity stubborn, you may need to resort to a stronger cleaner like Algae Strip and deal with the cosmetic damage it may cause, after you get the growth off. Algae Strip is safe for cleaning fiberglass and will not damage rubber, but will attack paint, etch aluminum and darken stainless steel.

To clean heavy growth, you will need a combination of chemical bottom cleaning and mechanical scraping. I suggest starting with the more aggressive Algae Strip to get the heaviest growth off and then switching to Algex as you get closer to the substrate. Be careful using any metal tools to remove the barnacles as they can cause more damage to the outdrive.

I dont know anything about these products so it would be best to do a litle research on them before attempting to use them. You should also remove the water intake plates to clean out the inlets. Barnacles are known to make their home in these areas as well. Restricted water intakes will cause you motor to overheat.

[wplaine]

I had the same problem. They came off with a plastic ice scraper once they had dried out. You can use a metal one just be careful not to gouge the outdrive. While still wet and semi alive it is a pain! So let them dry out. Then a little 400 grit sanding by hand on just the remains took them off with little paint removal. Still had to prime and paint the outdrive again but it looks waaaaay better now.