Accidentally backed As You Wish

The folks at Blue Water Yachts sell a replacement rubrail kit but mention that it is "very difficult to install" requiring "hard stretching" (probably for both my body and the rubber). There will probably come a day where I will try that, but it is not this day.

In the meantime, I picked up some of this black LifeCalk on Amazon and figured I'd give it a try:

It says it is 'sandable and paintable', so I'm hoping that once it cures I'll be able to shape it enough to end up with something that at least seals things up and makes the damage less noticeable until she has enough war wounds in other spots to where I can justify replacing the entire rubrail. The black goop seemed to go on ok, though I did not expect the back of the tube to explode when I squeezed it on, which made it get all over my hands, my shirt, the driveway, the dog, the dog's favorite toys... you get the idea.

Not the prettiest, but already looks at least a little better. We'll see how the finished product looks after it cures and is sanded down a bit. Any predictions on how this will turn out?
As a side note: have any of you tried replacing the rubrail on a Mac yourselves? I'd love to know how it went and what kind of effort is really involved.
- Mike
