Mailport October 2012 Issue

Mailport: October 2012

Lightning Protection

The Canadian builder, now apparently defunct, of two wooden masts for my Benford 34 junk-rigged schooner inexplicably ignored the plan for the foremast I sent him, and he did not provide a way to pull a lightning conductor through it.

Drilling 10 inches into the center of the masthead suggests no cavity. In your judgment, is there a reasonable way to run an AWG 4 cable outside the mast to a suitable submerged copper sheet—as I will for the mainmast, which if the 45-degree rule is correct, will not protect the head of the foremast? I’m asking you because I sense you and your associates like compound, probalistic, and ambiguous problems of this sort!

Stephen Sittler

Benford 34

An outside-the-spar run of 4-gauge wire, though not elegant, will work on a wooden spar, as long as hoops are not the chosen mode of sail attachment. Be sure to avoid potential chafe points, and add chafe protection if needed; also, we recommend using plastic straps rather that stainless straps to hold the wire run in place.

If possible, the wire should not be cut, and avoid a terminal connection where the wire penetrates the deck. Perhaps it can be led through the partners directly to the bilge, where an unbroken connection is made to the external underwater conductor.

Next: Prosine Problems

Comments (0)

Be the first to comment on this post using the section below.

New to Practical Sailor?
Register for Free!

Already Registered?
Log In