Replacing the D Ring

on the Bow a Pre-Rondar Viper


The D ring on my bow snapped off after hitting the dock one day.

I was faced with replacing the D ring, a critical component on a Viper
because it ties off the end of the tack line for the spinnaker and secures
the spinnaker pole from bending too far under stress.

Here’s what I found out…

I first tried to remove the D ring from the outside by using an awl and hammer. It was impossible.

This left me with two choices:

  1. Cut a hole in the topsides to gain access – which would be very ugly
  2. Install a 6″ diameter inspection port in the flat section of the spinnaker retrieval opening as far forward of the spinnaker sock as I could.

I chose the latter and the installation looks very professional. However this turned out to be a tricky job.

The easy part was cutting the hole for the inspection port.The project got considerably more difficult from there on. As I cut the opening I found that I also was cutting through some wood supports that are glassed to the fiberglass tube in which the spinnaker pole slides. I used a Rotozip drill bit to cut the hole. Be careful to not go too deep as you do not want to cut into the fiberglass pole at this step. I had removed the carbon pole prior to any cutting. Once I had a hole cut and could see what was going on, I had to make a single cut through the fiberglass tube and remove the aft 8-10″. This was simple, but was necessary to be able to get my hand past it and to be able to look inside at the bow. What I found was that the D ring had been installed prior to the deck going on as there was no access to the nuts which held it in place as they were epoxied over and it is impossible to reach.

So I decided to drill through from the outside, one hole between the two existing legs of the D ring and then the second hole just below the lower original hole. By doing this both holes were still fairly centered in the inner epoxy. Buy the new D ring first so you know how to space the holes. The next part was quite difficult because you cannot reach the bow from the access port. My reach was about 6″ short. So what i did was use a socket with a screwdriver type handle, placed the nut inside and then had to blindly find the bolts. I was able to get a backing plate on one of the bolts, but gave up on the second. I do not think the backing plate is necessary as there is plenty of epoxy built up there. I was able to get both nuts on and tighten them.

The next task was to fiberglass the tube that I previously cut back together. It took me a few tries to do this to make it water tight. Somewhat critical step here because any water that enters the pole opening in the bow will go directly into the bilge of the boat if this is not watertight. Normally water entering the tube just flows through to above decks below the spinnaker sock.

Make sure to also seal the aft end of this tube, as I found it had broken away from the bulkhead over the years. This is the point that I determined where water enters the bilge just sitting in the parking lot from rain. There was always water in the bilge prior to launching every Saturday. After I sealed this I never had the water problem again.

The correct length of the tack line is when the pole is fully extended the tack of the spinnaker should be at the pole end. This tack line runs as follows:
From the D ring it enters the bottom hole at the pole end, once inside the pole it goes through a single block and then exits the top hole of the pole. The block inside the pole is attached to a shock cord which goes aft, then exits the inboard pole end, goes through a cheek block mounted either on the Delrin block just forward of the mast or to the mast itself. It then goes all the way forward on the port side of the boat to a block mounted just under the forward edge of the spinnaker sock, then finally goes aft again and ties to the pad eye for the jib halyard block just before the jib halyard goes up through the deck. Adjust the length of the shock cord as needed, not too tight and not too lose.