A lot of production cruising boats have iron keels. While lead has traditionally been considered the material of choice for keels, iron works fine and helps builders lower the cost of their boats. But iron rusts, which can make it hard to keep anti-fouling paint in place and beat the slime, barnacles and weed. Here’s a solution.
First, grind the rust spots on the keel down to bare metal and then sand the whole keel with 120 grit sandpaper. Clean the bare spots with Ospho to kill the rust and dry thoroughly. Next, cover all of the bare surfaces with underwater epoxy and fair into the surrounding area. Interlux’s Performance Epoxy (two part) works well.
Next, prime all of the epoxy areas with several coats of an epoxy primer such as Interlux Interprotect 2000 VOC. Then, prime right over the whole keel with a couple of coats of the hard primer.
Finally, cover the boat’s bottom with antifouling paint suitable to your location and to the use you will be giving your boat. If you killed the rust spots and sealed the iron completely with epoxy paste and primer, you will eliminate most of your rusting keel hassles. But unless you strip the keel completely and seal it in epoxy, this touch up process will be ongoing for as long as you own your iron keeled boat. For useful information, visit the International Paint website at www.yachtpaint.com.