Chainplates

We have started the process of exposing the chainplates. This raised a few questions. One of the previous owners, Keith Essex, claimed to have had extensive refit work done on Veritas (then named Nunatak). On the order of $200k in 2010. He told me (via email) that all the chainplates had been replaced in Mazatlan Mexico. I contacted Marine Services Mazatlan, Richard Cummings, but his records records only go back to 2012.

The caulking at the deck appeared to be good condition. Several bolts are askew. Some bolts have washers some do not. Whether the work is new or original, the appearance is low-quality. Once everything is exposed we will ask a rigger to take a look.


When we finally got around to pulling one of the chainplates it seemed to be it good condition. The rust stains were from the 304 ss bolts and washers. Unfortunately, the plywood core felt damp. After removing all the chainplates we had the knees inspected. The moisture readings were not elevated badly and the glass work appeared to sound. Overall the recommendation was to stop any additional water ingress and allow the knees to dry over the winter.

We found that the chainplates installed for the foward lower shrouds appear to be intended for the intermediate backstays (they are smaller 38mm x 9.5mm stock) were installed at the forward lower shrouds. These will need to be replaced as the pin hole 5/8" should be 1/2" for the 5/16" wire specified on the design drawing.

We decided to replace all of the chainplates along with the bolts and backing plates. The faces of the knees will need to be cleaned up as well as the bolt holes. The through deck openings will also need to be cleaned up.

The faces of the knees will need to be cleaned up as well as the bolt holes. The through deck openings will also need to be cleaned up. The pictures below show the starboard cap shroud knee after removing the chainplate. Note the polyester fairing compound that had to be removed. There was a sigificant gap between the two surfaces.

Just a boat load of surprises! This is the back side of port forward lower knee (above). The holes are hogged out and chainplate was installed at an odd angle. It should be parallel to the inside edge of the knee (roughly inline with the shroud). Check the starboard forward lower (below, it looks ok).

Ideally the the face of each knee should offer a flat surface for the chainplate. The photo below shows the irregular surface of the port forward lower knee. The gap will need to be filled with high density epoxy fairing compound so that the forces applied to the chainplate will be distributed more evenly.

General Notes: All chainplates are bolted to the knees with 3/8" x 16 bolts. Length varies from 3 1/2" to 4". Made from 304 ss, most of the bolts used were tap bolts (fully threaded). They will be replaced with 316 ss shoulder bolts. A polyester fairing compound was applied to the edges of the chainplated and backing plates to hide the irregular surface. The bolt pattern is the same for all knees. It consist of six bolts in two rows of three. The rows are separated horizontally by 20.6 mm (13/16"), while the bolt holes are separated 63.5mm (2 1/2") vertically. The bolt holes are oversized at 11.1mm (7/16"). The pin hole for all chainplates is 15.9mm (5/8") and 127mm (5") above the bolt pattern.

Port (#16) and Starboard (#20) Forward Lower Chainplates: Both chainplates are undersized. It appears they were intended for the Intermediate Backstay and mistakenly bolted in this location. Measuring 38.1mm (1 1/2") wide and 9.5mm (3/8") thick, they appear to be made from bar stock. The width is too narrow for the pin diameter and the bolt pattern.

Port (#13) and Starboard (#2) Cap Shroud Chainplates: Both chainplates are sized correctly, 47.6mm x 9.5mm (1 7/8" x 3/8"). However, the port chainplate has large gouge that appears to have been made while cutting off a bolt.

Port (#9) and Starboard (#9) Aft Lower Chainplates: Both chainplates are sized correctly, 47.6mm x 9.5mm (1 7/8" x 3/8") with the exception of oversized bolt holes. However, the starboard side backing plate was made from 38.1mm x 4.7mm (1 1/2" x 3/16") stock.

Port (#199) and Starboard (#17) Intermediate Backstay Chainplates: Both chainplates are somewhat oversized as oversized shouds were installed (3/8" vs 5/16"). It can only be guessed that the forward lower chainplates were intended for this location.

New Chainplates: Overall length 494.5mm (19.47"), width 50mm (1.97") and, 9.5mm (3/8") thick. Pin diameter 15.9mm (5/8") for forward lowers, aft lowers and cap shroud (total of 6). Pin diameter 12.7 mm (1/2") for the intermediate backstays (total of 2). With a bottom corner radius is 10mm and a top corner radius is 20 mm,

New Backing Plates: Overall length 367.5mm (14.47"), 50mm (1.97") and, 4.7mm (3/16") thick ss backing plates or 6.5mm (1/4") G-10. All corners rounded with a radius of 10mm.

New Deck covers: 4.7mm (3/16") thick: outside rectangle 92mm x 54mm (1 9/16" x 2 1/8") with 6.35mm (1/4") radius corners, centered rectangular hole in plate 51mm x 10mm, with four 5mm counter sunk screw holes centered on the corners of a rectangular pattern 60mm x 30mm.

For 3/8" sheet stock

For 3/16" sheet stock