We first posted our ideas for redesigning the leaky chain plates on the C34 and C36 (1996-2003) models on February 19 this year in the Technical Discussion Forum. In speaking to some fellow sailors it appears as if the problematic chain plate design goes back further than 1993. Based on some great feedback, we modified our final chain plate design and are currently having them made at a machine shop. We’ll demonstrate the final design in an article for the Jibsheet and the Technical Upgrades section that we plan to write when the whole job is done. For now we describe removing the old chain plates and readying the deck.

[U]Removing the old chain plates[/U]
Our experience is with the C34 which is the same as the C36 in this regard except for the center chain plate on the C36 which is a long bar with several bolts through the bulkhead rather than the rods connecting the other chain plates to the hull. Removing the rods is straight forward. It’s just a matter of removing the nut from the hull attachment end of the rod and then unscrewing the rod from the chain plate itself. Access is no problem.

To remove the actual chain plate, do the following: 1) Remove the small cover plate on the deck. Get under it with a putty knife to break the seal or else you risk lifting away some of the gel coat (as happened to us with one of them.) 2) Remove the nuts from the through bolts holding the chain plate to the deck. 3) Break the seal between the bottom plate of the chain plate and the underside of the deck (putty knife again). 4) Work the chain plate loose from inside the cabin.

You will be left with a rectangular hole (“slot”) which requires cleaning. Note the black (i.e. mildew) staining we found on the removed chain plate [B](Image 1)[/B] and on the underside of the deck (i.e ceiling of the salon) [B](Image 2). [/B]5) Now remove the two 3/8” though bolts.

Readying the deck
Next steps are:
1) Removing old sealant
Depending on what was previously used as the sealant, it can be fairly easy or difficult to remove. The slot was cleaned using a rotary tool with a cleaning bit.[B] (Image 3)[/B] Luckily we didn’t notice any rot in the wood core but look for this and remove what you can. If it turns out there is rot beyond reach, then you have a bigger job to do than just worrying about the chain plate.

2) Cover the slot opening from the underside of the deck with masking tape then coat the inner surface of the slot with thickened epoxy to seal the exposed core. (This is the part that should have been done in the Catalina factory during production). When it is cured, remove the masking tape and use a rotary tool to remove the epoxy that pooled and cured around the slot opening at the underside of the deck.

3) Next use a rotary tool to create a chamfer around the slot opening on the topside of deck. [B](Image 4)[/B]

4) Since the deck through bolts often also leak, drill out the bolt holes using a 5/8” bit, use a 1” counter sink to create a chamfer [B](Image 5)[/B] then fill the hole with epoxy, allow it to cure and redrill with a 3/8” bit to fit the through bolts.

This will result in the deck being ready to receive the new chain plates. Note this process can be followed even if you are simply going to re-install your original chain plates.

Our next posting will discuss the chain plate re-installation process we followed.

Tony Germin Rick Verbeek
1997 C34 #G697 1999 C36 #1763

Lakeshore Yacht Club
Toronto, Ontario