On Thu, 18 Nov 2004 23:39:14 GMT, "Frank Gerry"
wrote:

Has anyone seen this problem before. This fall, I attempted to repair
leaking deck though-holes. My Cal 28 uses U shaped bolts for the anchors to
the mast stays (instead of chainplates).
The deck through-holes were 3/8 inch diameter, so I drilled thru the deck
with twice the size diameter holes (3/4 inch). I then taped underneath and
filled in the holes with fiberglass resin. A week later, I inspected the
glassed in holes and discovered some were leaking as badly as before.
The mistakes I made I think were 1) the inside of through-holes were still
wet when I poured the resin, and 2) I used polyester resin and not epoxy
resin.
Anyone have any suggestions what I could do before I head out and re-drill
these.

You are on the right track. Clean out the holes completely. If you
have a cored deck (likely), use a bent nail end or a small Allen key
to gouge out each through-hole. Tape as before and then use a
thickened epoxy. Thicken with something that won't wick moisture, like
microballoons. Thicken to a mayonnaise consistency. Pour into the
holes and let set completely (depends on temperature. Keep all this
dry as possible. Put a weight on the spot because you want the deck
"skin" to bond to the epoxy. Use a slip of wax paper between the
weight and the holes.

When dry, drill through the center. Essentially, you've made about a
1", lens-shaped washer in the core of the deck. If done properly, it's
isolated the core from the outside world.

Fill the holes with some bedding like 4200. Push the U-bolts through.
I assume there is some sort of backing plate on the bottom? If so, put
a bead of bedding completely around the perimeter of the plate, but in
a bit as it will spread when compressed, which is wasteful and messy.

Dog down the bolts, but not too tightly. You want the bedding in the
bead and in the holes to partially set up...read the directions and
figure out when this will be.

Dog down the nuts tightly when appropriate.

Tape off the area around the bolts on deck Put a tiny bead around the
shaft where it enters the deck. When dry, pull away the tape and trim
with a utility knife.

This is SOP on my boat and while I get a bit of rain in the poorly
designed companionway, I have no water coming through any bedded deck
gear.

R.