Mark, thanks for your input. I'll look into the grounding plate idea--although I agree it sounds like I'm adding a maintenance chore, and it won't be very compatible with my float-on trailer...
The lead keel idea came about, actually, because I WAS doing other things that I wanted to do--replacing shrouds, lifelines, and painting the whole boat. I'm doing the painting on the trailer, and the whole base of the keel rests on a carpeted block. Therefore I could not clean off the old bottom paint nor can I apply primer and paint. So I elected to sand whatever I could bare, up to about nine inches from the base of the keel. I taped off a line and stopped all my paint at that point--I've got five coats of Interprotect 2000 barrier coat on the entire hull and keel down to the tape (I know I don't need barrier coat over lead, but since the lead keel was neatly faired to the hull, it made for a smoother transition and a good primer for the bottom paint) and then a couple coats of Pettit Vivid. When I pulled off all but the 1" strip of blue tape, there was a striking effect to the exposed half-inch of 3M blue next to the Vivid green and the silverly lead. I decided that since I'm doing all this work, I'd like to keep that effect, so I'm splurging on a quart of VC Offshore and will paint that same color stripe below the Vivid and also above it between the waterline and boot stripe. Because that's coming by mailorder, I have time yet to decide that I'll paint the entire keel tip with VC Offshore.
Please take a look at my reply to Phil about the idea of dissipating the static buildup rather than dealing with the lightning discharge itself. I still wonder (maybe it's wishful thinking) whether six square feet of exposed smooth lead wouldn't work just fine to help keep my entire boat at the same electrical potential as the water...
Thanks for all the help!
David Shaddock
----- Original Message -----
From: Mark Tamblyn <[EMAIL PROTECTED]>
Date: Saturday, July 15, 2006 9:40
Subject: RE: catalina27-talk: Lightning
To: [email protected]
> Like you I have been a part of this debate in past years.
>
> If you dig around on the internet you will find info on the best
> way to do the job. A special grounding plate is required (not
> the plate for a HF radio) this has angles and edges that can
> pass the current into the water. As Phil pointed out flat ribbon
> is often used for bonding and flattened copper pipe is sometimes
> used to connect the mast.
>
>
>
> After going to the extensive efforts involved in doing all this
> you will gain a new periodic maintenance job too. Clean and
> check all the bonding attachment points.
>
>
>
> IMHO
>
> This is something I would do if I was a live aboard in Florida
> or the tropics. For the occasional use my boat gets (lets face
> the facts) I would be much better served to put that time effort
> and money into something that would either give me more pleasure
> (a paint job) or added safety like lifelines, running rigging,
> new main sail ... the list is endless.
>
>
>
> Mark Tamblyn.
>
> 1976 C27 Josephine
>
> Gloucester Point VA (on the sunny Chesapeake bay)
>
>
>
>
>
> ________________________________
>
> From: [email protected] [mailto:catalina27-
> [EMAIL PROTECTED] On Behalf Of [EMAIL PROTECTED]
> Sent: Saturday, July 15, 2006 10:15 AM
> To: [email protected]
> Subject: Re: catalina27-talk: Lightning
>
>
>
> The topic of lightning has been one of great interest to me
> since buying a sailboat a few years ago. Open water, big
> metal pole, metal wires all over the place...seems inviting for
> a lighting bolt. I believe Boat US last year said that
> over the last ten years they only had 3 cases of lightning
> strikes that resulted in death. That was a little
> comforting. They also said that a survey showed (and I am
> going on memory so figures may not be exact) that in FLA your
> boat has a 8% chance of getting hit by ligtning and in the
> Chesapeake Bay it is 4%. Those are the two highest places
> of incidents. I sail the Chesapeake and 4% sounds like a
> big number to me.
>
> One article a few years ago in Sail or Cruising World a person
> recommended no grounding of the mast because that will draw the
> bolt to your boat. Of course, getting hit without
> grounding doesn't sound wise. My course of action probably
> will be just to carry a set of jumper cables on the boat and
> connect to the shrouds and drop other end into the Bay during a
> storm. That probably will work ok at anchor but not
> thinking that will work underway.
>
> So far I have only dealt with one electrical storm while
> underway (and that did not contain much lightning) and none
> while at anchor.
>
> I know the topci always "sparks" some debate...which seems to be
> appropriate with temps rising to almost 100ยบ this week on the
> Cheasapeake!
> Dave Tierney
> Celtic Pride, 5282
> 1983 C-27, Traditional
> Middle River, Maryland
>
>
>
>
----- Original Message -----
From: Mark Tamblyn <[EMAIL PROTECTED]>
Date: Saturday, July 15, 2006 9:40
Subject: RE: catalina27-talk: Lightning
To: [email protected]
> Like you I have been a part of this debate in past years.
>
> If you dig around on the internet you will find info on the best
> way to do the job. A special grounding plate is required (not
> the plate for a HF radio) this has angles and edges that can
> pass the current into the water. As Phil pointed out flat ribbon
> is often used for bonding and flattened copper pipe is sometimes
> used to connect the mast.
>
>
>
> After going to the extensive efforts involved in doing all this
> you will gain a new periodic maintenance job too. Clean and
> check all the bonding attachment points.
>
>
>
> IMHO
>
> This is something I would do if I was a live aboard in Florida
> or the tropics. For the occasional use my boat gets (lets face
> the facts) I would be much better served to put that time effort
> and money into something that would either give me more pleasure
> (a paint job) or added safety like lifelines, running rigging,
> new main sail ... the list is endless.
>
>
>
> Mark Tamblyn.
>
> 1976 C27 Josephine
>
> Gloucester Point VA (on the sunny Chesapeake bay)
>
>
>
>
>
> ________________________________
>
> From: [email protected] [mailto:catalina27-
> [EMAIL PROTECTED] On Behalf Of [EMAIL PROTECTED]
> Sent: Saturday, July 15, 2006 10:15 AM
> To: [email protected]
> Subject: Re: catalina27-talk: Lightning
>
>
>
> The topic of lightning has been one of great interest to me
> since buying a sailboat a few years ago. Open water, big
> metal pole, metal wires all over the place...seems inviting for
> a lighting bolt. I believe Boat US last year said that
> over the last ten years they only had 3 cases of lightning
> strikes that resulted in death. That was a little
> comforting. They also said that a survey showed (and I am
> going on memory so figures may not be exact) that in FLA your
> boat has a 8% chance of getting hit by ligtning and in the
> Chesapeake Bay it is 4%. Those are the two highest places
> of incidents. I sail the Chesapeake and 4% sounds like a
> big number to me.
>
> One article a few years ago in Sail or Cruising World a person
> recommended no grounding of the mast because that will draw the
> bolt to your boat. Of course, getting hit without
> grounding doesn't sound wise. My course of action probably
> will be just to carry a set of jumper cables on the boat and
> connect to the shrouds and drop other end into the Bay during a
> storm. That probably will work ok at anchor but not
> thinking that will work underway.
>
> So far I have only dealt with one electrical storm while
> underway (and that did not contain much lightning) and none
> while at anchor.
>
> I know the topci always "sparks" some debate...which seems to be
> appropriate with temps rising to almost 100ยบ this week on the
> Cheasapeake!
> Dave Tierney
> Celtic Pride, 5282
> 1983 C-27, Traditional
> Middle River, Maryland
>
>
>
>
