Replacing the Bristol 29 Chainplates

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Replacing the Chainplates

Ever wonder what 35 year old chainplates look like? Here is the starboard main removed...

This is the outside face; little rust and no obvious fractures from crevice corrosion. I will Magnaflux all of them before replacing them.

This is the inside face against the forward side of the knee. More rust staining shows, indicating that there was some water getting down the back side of the chainplate at one time. Everything was dry when I removed it, and no rot or softness is present in the knee.

Here is the aft face of the knee. And here are the three bolts holding the chainplate in place.

As far as I can tell Bristol made these chainplates; the dimensions and hole spacing do not match anything sold by Rig Rite, although the deck covers look like Rig Rite covers.

I will replace the mains with Schaefer chainplates # 84-90. According the Schaefer catalog, the stock Bristol chainplates are undersized for the main shrouds. As a matter of fact, according to Schaefer, the Bristol chainplates should be used with a maximum diameter of 3/16" shroud. My B29 came stock with 1/4" mains and I upgraded them to 9/32". The Schaefer 84-90's take 1/2" pins and will be sized correctly sized correctly.

January 7

I removed the remaining chainplates today. All looked like the example photos above: none had serious rust or crevice corrosion issues; none of the bolt holes had soft wood or structural problems. I will fill all the existing holes with thickened epoxy and drill new holes for all the new chainplates. The mains will be located about two inches outboard of the existing slots in the side decks and those existing slots will be filled in.

You're looking at the new main chainplates getting sprayed with Nyalic fluoropolymer to protect them from any possible crevice corrosion. These are Schaefer #84-90's: big hurkin chainplates, twice the size of the originals, 1/4" thick and a hefty 1-1/2 pounds each. They attach with 5 1/2" bolts and are sized for 1/4 to 9/32 wire size (I have 9/32" wire for the main shrouds). To mount the chainplates, I ordered all new hardware: bolts washers, fender washers and nylon locking nuts, all of 316 stainless, from McMaster Carr.