Bottom Job with a cast iron keel

[markwbird]

I'm getting ready to do a bottom job on my 1984 H34. I plan to do it myself. It's been three years since the last one which was done by the pros. At that time the cast iron keel was barrier coated. So, do I need to barrier coat the keel again? How can I tell if I need to barrier coat it or just sand and paint with the bottom paint?

 

[whatfiero]

Rust. You will see the rust. If it's just a few spots then you can do just those spots if more than grind whole keel down. But needs to sit a few days after pressure wash for rust to work it's way to surface

 

[Richard Bryer]

I stripped the bottom right back to the gelcoat on mine 4 years ago. At that time the keel was showing patches of rust. I stripped everything off down to the bare metal with a needle gun ( lot of work) then immediately coated it with a rust converting compound, then as soon as it was dry a coat of Interlux 2000. I then faired it with an epoxy fairing compound then coated it with 4 more coats of Interlux. It seems to be resisting any rust- every year at haulout I may see one or two very small spots that ooze a very little bit of rust. I Dremel them out and fill with the fairing compound the put on the antifouling.
I would say if you are not showing any rust spots just paint it.

 

[kloudie1]

If they did a good job three years ago, you will have a little touch-up and then paint with bottom paint.. Don't sand aggressively on the barrier coat unless there is a problem..

 

[Crazy Dave Condon]

strongly suggest that you coat any sanded cast iron keel area with a metal primer first that contains zinc chromate is a must. Then if any voids fill with a two part epoxy and sand smooth. Prep is the key here. As for a recoat, I would lightly sand the existing barrier coat to make sure all crud is off but most importantly giving you a good grip for a new barrier coat to adhere to