Removing barnacles from outdrive

[Quickstep192]

The lower unit of the outboard on my Quickstep is in the water constantly. This year, it got crusted with barnacles. I scraped the barnacles off while it was still wet, but each of the barnacles left a thin adhesive like circle behind that is completely resistant to a wire brush. Is there a trick to getting this stuff off?
It's a small motor, so it would be easy to dunk it in a bucket for a while.

[sailingdog]

I believe that vinegar will get the circles off... You might want to get some antifouling paint for your outboard. The stuff they use on stern drives and outdrives should work, since they're basically fairly similar in construction.

[Quickstep192]

Originally Posted by sailingdog

I believe that vinegar will get the circles off... You might want to get some antifouling paint for your outboard. The stuff they use on stern drives and outdrives should work, since they're basically fairly similar in construction.

Dog, That's the really bad part. It had antifouling paint. Unless something new has come along, outdrive anti-fouling doesn't last long.