Saturday, March 20, 2010

Modifications for Chainplate Installation

I've made most of my standing rigging decisions and have ordered some of the components.  This was necessary at this stage of the project, since switching to chainplates to anchor the lower ends of the shrouds required some modifications that needed to be done before finishing the fairing and painting. This mainly entailed removing the plywood shroud lashing pads that had been installed as shown on on the plans and adding in their place teak backing blocks for the lower ends of the chainplates, where they extend below the doubled section of the sheer stringer.  You can see the need for these backing blocks in the photo below.  This is not an actual chainplate, but rather a full-size pattern made in aluminum.

The chainplates will be a total of 12 inches long, allowing enough length on the upper bent section to provide clearance between the cabin side and the Precourt chainplate terminator.  The #316 stainless steel blanks in the background will be used to make the actual chainplates.  These will be more than strong enough, at 1 1/5" wide by 3/16" thick. 

Here are some of the Precourt chainplate terminators and matching deadeyes.  I ordered these directly from Erik at Precourt and received great service.  These are the Small Series, which are even larger than needed for a Tiki 26, but are sized in a way that will allow me to rig with either 1/4" Amsteel Blue or 7mm Dynex Dux, either of which will provide a higher working load than the SS wire specified in the plans. 

There are several reasons I'm going with synthetic rigging instead of wire, including saving weight, the ability to reliably splice the rigging without any hardware required, and the ease of carrying plenty of spare rigging material that will weigh hardly anything.  Once the deadeyes are purchased, the most expensive part of this system can be used again and again, as these never wear out or have to be replaced like turnbuckles and wire rigging fittings.  Aesthetically, I think the deadeye and synthetic rigging system just looks right on these boats, and is in keeping with the Wharram philosophy of minimizing hardware and keeping things simple.  Of course the chainplates and deadeyes cost more than the simple lashing pads as shown on the plans, the advantages are worth it in my opinion, as it is easier to get better rig tension and the secure lower shroud connections add a measure a safety when stepping and unstepping the mast.