Cheoy Lee Restoration Issues

Cast Iron Ballast


Surface Treatment of Ballast......

A. Epoxy Coating
B. Chemical Coating

Hull/Ballast Joint

There are two issues related to the cast iron ballast.
   1. Treatment of ballast surface before applying bottom paint
   2. Joint between ballast and hull

1. Surface Treatment

The Clipper Series (I am not sure what other models are the same) have a cast iron ballast.  I found, when grinding my ballast down to remove the bottom paint, that the casting was of poor quality.  There were several chunks of square metal embedded in the sides of the ballast which showed that junk metal scraps were thrown into the molds before pouring.  This caused uneven cooling and several areas of my ballast are very porous.  This problem adds to the complex issue of how to coat the iron to prevent rusting when the surface is not smooth.

There are at least two approaches to this problem. 
  A. Epoxy Coating (see sidebar below)
   B. Chemically treating metal surface (click here)

      A. Epoxy Coating - The first approach is to coat the surface with epoxy.  Following is a letter we received from the West System engineers outlining this approach...

James & Cilla,
Enclosed are instructions for applying epoxy to cast iron.  Once you have a layer of epoxy properly applied to the keel, apply a layer or two of fiberglass to the epoxy surface coat.  I have also enclosed information about that process.
Metal Preparation.. Thoroughly sand the surface with coarse sandpaper to provide good mechanical keying for bonding.  Wet-out the surface of the hardware with epoxy. While the hardware contact surface is still wet, abrade the coated surface with coarse sandpaper, working the epoxy into the metal surface. This technique exposes fresh metal directly to the epoxy without any air contact and the possibility of oxidation.
Applying Fiberglass Cloth, Wet method:
An alternative to the dry method is to apply the fabric to a surface coated with wet epoxy. This is the more difficult method when applying large pieces of thin cloth. However, this method is useful or necessary in some situations. When applying heavy fabrics on porous surfaces, the wet method helps to assure the substrate is thoroughly wet out. Cloth can be applied after the wet-out coat becomes sticky, helping it cling to vertical or overhead surfaces.  Pre-fit and trim the cloth to size. Roll the cloth neatly so that it may be conveniently rolled back into position later.  Roll a heavy coat of epoxy on the surface.  Unroll the glass cloth over the wet epoxy and position it. Surface tension will hold most cloth in position. If you are applying the cloth vertically or overhead, you may want to wait until the epoxy becomes sticky. Work out wrinkles by lifting the edge of the cloth and smoothing from the center with your gloved hand or a squeegee.
Apply a second coat of epoxy with a foam roller. Apply enough epoxy to thoroughly wet out the cloth.  Remove the excess epoxy with a squeegee, using long overlapping strokes. The cloth should appear consistently transparent with a smooth cloth texture.
Any remaining irregularities or transitions between cloth and substrate can be faired by using an epoxy/filler fairing compound if the surface is to be painted. Any additional fairing done after the final coating should receive several additional coats over the faired area.
You might want to request our free “WEST SYSTEM User Manual & Product Guide”.   A text-only version of that publication is available on our World Wide Web site.
Brian Knight
Technical Advisor
100 Patterson Ave., P.O. Box 908
Bay City, MI  48707-0908
tel:  517-684-7286
fax:  517-684-1287


     B. Chemically treating metal surface

This is a method that one of our members Albert LaMarche aboard Providence has used and following are e-mails sent in by him.  I am inclined to use this method since it sounds like far less man hours.  I assume that the product that Albert used is similar to a product I have used around the house that I purchased from Wal Mart.  If was sold as a rust converter, a friend said it converts rust to a co-polymer, but on my riding lawn mower etc. it has worked great.  It turns the rusty surface to a hard black coating.   I will keep you informed if I use this method and will take pictures as the process proceeds.  james...

     Ive spent a week removing the gelcoat from my keel and am still not finished...a small 4 1/2 " grinder with a 38 grit sanding disk works great...I read west system's comments with interest...particularly about sanding to bare metal...good luck, the rust on my keel penetrated  1/8 to 1/4 inch, so I took another approach...

    prior to taking off all the gelcoat I sprayed (bottle sprayer) two coats of phosphoric acid (West Marine sells it under the name "rust-lock metal prep" ) (page 172 of current catalogue - james)  two days later I started  removing the gelcoat any way I could; sanding, grinder, pressure sprayer, and a few improvised tools like autobody pick hammers etc...I then went back to the sanding disks on the grinder...what I found was that the rust had turned to iron phosphate over almost all but a few small patches of rust of the keel...using the pick hammer I was able to loosen most of the flaking iron..the iron phosphate penetrated all the way to the base metal and left a very hard black surface that can be finished...

    the rest of my plan is to grind away the rest of the remaining gelcoat particles and re-treat the keel with phosphoric acid several more times for best penetration (to the keel bolts if possible)...this will be followed by coating with a premium marine metal primer, sanding, followed by applying westsystem's gelcoat with a filler to smooth over the rough surfaces... applying a good hydroscopic marine paint to prevent water permeation through the gelcoat...then bottom paint....  Albert L...

Here is follow up letter from Albert after one season in water...

James..... this is a follow up to my original email regarding the preparation and restoration of the rusting keel on my 33 clipper...
This afternoon we pulled Providence after being in the water for seven months... there were no, repeat no,  rust spots or flaking metal anywhere on the keel... the product POR-15 sealed the keel thoroughly and has held tenaciously to the prepped metal...

Hope that your restoration is going smoothly.......

                                Al LaMarche

2. Joint between ballast and hull

Keelcloseup.jpg (21002 bytes)
Click to view

Here is shot of stern portion of my ballast, note seam opening between ballast and hull

The joint where the cast iron ballast meets the hull is a problem.  On my Clipper, when she was pulled from the water, this seam was damp for several days.  My concern was that water must have a path to the keel bolts causing possible corrosion
  There has been two suggestions made by others.  One is to glass over this seam and the other is to use a material to fill the crack.  Below is one e-mail that suggest using sikaflex.  I have not decided which method to use on our Clipper.    Does anyone else have any experience with sikaflex??







Here is excerpt from e-mail message I received from Bob W.. onboard "Bolero" a 69 Clipper 36
Great to know there are many "69's still around.  With care they should make a 100 years! 

Mine is a Clipper 36 built in '69.  Have replaced or rebuilt everything at least once.  No experience with the keel problem.  I've used Sikaflex where it joins the boat, but nothing fancy.  Bolts a worry, but never did the X-ray routine.