(I bought a 1972 Oday 22 for $500 18 months ago. Including the trailer and titles for all. She's a bit rough, but I sailed her last season and certainly got my money's worth out of her. Now I'm looking at doing some repairs, despite having never done this sort of thing before. The worst thing that happens is I destroy a $500 boat.)
The rudder of my boat came complete with an unbelievably shitty repair done by a previous owner.
The source of the damage was obvious: The repair was in the area where the rudder would contact the prop of the outboard motor. Clearly the rudder had sustained prop damage at some point.
The previous owner's repair was almost laughable: Some sort of cement, maybe even straight Bondo, just slapped on. I wish I had a photo of this. There was no sanding. No finishing done of any kind. It was rough light grey cement just slathered there and left to dry.
Of course, this was first on the list of things I was going to address. I got out the sander and took it off.
Of course, it came off easy--it wasn't really attached to anything.
That's when I discovered what it was covering up.
Not damage to the rudder, but an earlier repair of such damage. Underneath the cement stuff was a layer of fiberglass. Cloth and epoxy. Just one layer, wrapped around the outside of the rudder as a repair. Not wrapped the whole way around. It only extended about four inches forward from the trailing edge of the rudder.
The best thing about this layer of glass? It was laid over top of the blue paint of the rudder, which I can only assume was ablative bottom paint.
Now, what's the defining characteristic of ablative bottom paint? That's right. NOTHING STICKS TO IT. so, if course the single layer of repair glass wasn't actually attached to anything. I shook my head in stunned amazement, then peeled that layer of glass off with my bare fingers. Didn't need a tool.
So to recap: the cement blob was to hold down a peeling layer of glass that had been laid over ablative bottom paint. Successive layers of repairs, of increasing incompetence.
Well, now I've decided to restore the whole rudder properly. So I've sanded all that paint off and ground down the original damage and I'm preparing to lay up a real fiberglass repair, then fair the whole damned thing before repainting it. The rudder is going to be the nicest part of the boat soon.
And that's how I spent my morning.