Cliff notes, you -must- take it out and blast it at some point. You may be shocked at how little iron you find. I cannot emphasize enough how important it could be to your safety, especially on cheap old boats like Macgregors.
My Mac 25 was an ocean boat most of its life, and its keel looked uglier than most in the midwest. I got a lot of advice in prepping to remove it, for which I am grateful.
But.
I also ran into the “nah it’s normal” trope from many people, INCLUDING the folks at Strictly Sail Inc when I was trying to pay them to do it. “We don’t take keels out, we just hoist the boat, sand what sticks out and paint it. It’s all you really need, they’re iron and they’re going to rust anyways.”
Well I didn't listen, I built my own hoist and did the job myself. The rust line on the keel made it look as though it had never even been lowered for paint, instead being painted in the retracted position, on the trailer. In the photos you can see that even the halfazz job of slapping paint on what was exposed made a HUGE difference in the life of the iron.
The unpainted iron is deeply pockmarked and pitted, the keel bolt was only hanging on by a 3/8” x 1/2” thick ribbon of iron! The painted stuff still has a cast finish, with mild pitting only in places where it contacted things like the hull or trailer.
That little ribbon of iron was not long for this world, perhaps only a few years from succumbing to the 650lb weight of the keel a tearing out.
The simplest way for your boat yard to do this is likely to block/clamp the keel to the trailer, remove its hardware, and hoist the boat up and off (and put it on the hard, don’t camp out on the hoi$t). Wheel the trailer into the blasting booth and blast what you can reach (protect your trailer!), then immediately clean it with acetone and coat it with something like POR-15. In 6 hours you can then paint over that, either adding more barrier layers or going straight to bottom paint if the yard wants you out. Set the boat back down on the keel/trailer and reattach it. The bits of keel hidden by the trailer will now be exposed when you hoist the boat back up to do the normal bottom paint work-scope. I’m planning to do this extra step every 5~10 years.
My Mac 25 was an ocean boat most of its life, and its keel looked uglier than most in the midwest. I got a lot of advice in prepping to remove it, for which I am grateful.
But.
I also ran into the “nah it’s normal” trope from many people, INCLUDING the folks at Strictly Sail Inc when I was trying to pay them to do it. “We don’t take keels out, we just hoist the boat, sand what sticks out and paint it. It’s all you really need, they’re iron and they’re going to rust anyways.”
Well I didn't listen, I built my own hoist and did the job myself. The rust line on the keel made it look as though it had never even been lowered for paint, instead being painted in the retracted position, on the trailer. In the photos you can see that even the halfazz job of slapping paint on what was exposed made a HUGE difference in the life of the iron.
The unpainted iron is deeply pockmarked and pitted, the keel bolt was only hanging on by a 3/8” x 1/2” thick ribbon of iron! The painted stuff still has a cast finish, with mild pitting only in places where it contacted things like the hull or trailer.
That little ribbon of iron was not long for this world, perhaps only a few years from succumbing to the 650lb weight of the keel a tearing out.
The simplest way for your boat yard to do this is likely to block/clamp the keel to the trailer, remove its hardware, and hoist the boat up and off (and put it on the hard, don’t camp out on the hoi$t). Wheel the trailer into the blasting booth and blast what you can reach (protect your trailer!), then immediately clean it with acetone and coat it with something like POR-15. In 6 hours you can then paint over that, either adding more barrier layers or going straight to bottom paint if the yard wants you out. Set the boat back down on the keel/trailer and reattach it. The bits of keel hidden by the trailer will now be exposed when you hoist the boat back up to do the normal bottom paint work-scope. I’m planning to do this extra step every 5~10 years.
