China Doll Chain Plate Project...
Hi,
This is Rob from the China Doll... In answering one of your QST: the anchor for the chain plates did indeed pop out of the bonding, once the encapsulation 'cap' of about five layers of fabric were cut along the outlines of all 6 anchors embedded in the hull, cutting into the hull at just about the thickness of the plates. What was really interesting is the fact the chromium in the SS at the surface of the plates remain bonded to the polyester inside the hull. This left a 'blue tint' on the hull's inside surface in the glued in the resin. Just a slight bit of pressure using a small crowbar pried against the hull and the anchor sides did the trick.
Note that when ordering the grade 5 Ti plates, the anchor part that will be bonded to the inside of the hull, using West System epoxy thicken with silica, the most tenacious grip can be achieved by having the anchors sand blasted and not polished, as one would have for the outside 'show' portions of the plates. There's no need to have G5 Ti passivated as it has only one spot on the galvanic scale... At the very top, almost totally inert (G5 that is... Not CP Ti...).
With the sand blasted anchors I was able to bond into the hull the anchor using the same method as the original manufacture did, except I used epoxy silica and epoxied biaxial stitched cloth, in six overlap layers, to have a totally tie-in of the plate to the hull.
One original design aspect that I did change from the manufacture was to go with a two-part chain plate system; originally the anchor and thru-hull were one-piece. The new two-piece system totally seals the hull so no intrusion of water / moisture can enter the hull at the anchors. Before, the system could leak at the deck and being a common compartment straight up and out on the deck, if the chain plate covers leaked (which they did on and off over 25 years), that intrusion of water would fill the anchor cavity.
The whole design of the new system is available for review online in the Allied Titanium Catalog. Just look under boat type of Passport 51. And say hi to Chris for me...
-Rob.
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