Plastic doesn't hold up to "the elements" very well. Each of my new ports gets a coating of Rustoleum™ spray paint before it goes on.So the bits I bought to drill out the old corroded bolts were supposed to be cobalt bits; purchased from my local Home Depot. An online search re cobalt drill bits results mainly in confusion. Can anyone recommend a reputable brand of cobalt drill bits?
So I dropped by my local West Marine on the way home and bought a 4" inspection port, mainly because the color on that one seems closest to my white gel coat on the deck. I'm hoping that will be big enough to do the repair, but if some of you have experience with this and are convinced it's too small please let me know and I'll get a bigger one.
Granted, the following unpainted port could be 50 years old, but it's been degraded by the sun, and could actually crumble when I replace it: