This is not exactly the case. Keep in mind that a lighting generates a current in thousands of A. That high current generates magnetic field around it. In turn this magnetic field generates current in any conductor in the neighbourhood (this includes, but is not limited to, any electronic equipment (one assumes that there are some wires in it) and any metal object (e.g. keys in your pocket or the pushpit of the boat)). Grounding (or not) would not prevent the electronics from getting fried; bonding might (provided that it is correctly done and with sufficient wiring).
It seems that this is a good practice to ground the mast to the keel bolt, but in no way it provides all the protection you would want to have. Marek 1994 C270 “Legato” Ottawa, ON From: Robert Boyer via CnC-List Sent: Monday, July 25, 2016 11:41 To: [email protected] Cc: Robert Boyer Subject: Re: Stus-List Grounding a mast - 30mki Lightning is actually attracted to a grounded object. My boat has been hit by lightning twice--mast was grounded to keel bolt. Most of my electronics were fried each time. So, if anyone claims that grounding works, I think they have been more lucky than wise. Bob Bob Boyer s/v Rainy Days C&C Landfall 38 (Hull # 230) Annapolis, MD (presently in Baltimore) blog: dainyrays.blogspot.com email: [email protected] On Jul 25, 2016, at 11:31 AM, Bernard Bauman via CnC-List <[email protected]> wrote: I’ve heard in the past of this being done, but using chain. Does anyone know of instances where this actually works and prevents lightening bolt from entering the cabin? Bernie Ex C&C 25 (hull # 342) Shopping for a new boat Sent from Mail for Windows 10 From: Della Barba, Joe via CnC-List Sent: Monday, July 25, 2016 10:39 AM To: mailto:[email protected] Cc: Della Barba, Joe Subject: Re: Stus-List Grounding a mast - 30mki I run 4 gauge wire from the bottom of my mast to the nearest keel bolt. This is vastly better than nothing. If you really want to get into it, you would need to tie in all the rigging and provide exit terminals at the water line. This website will give you some ideas: http://marinelightning.com/Siedarc.htm . If you want to be cheap, do what we did dating back to the 1960s at least - buy jumper cables and pull them apart to make 2 separate cables. Clamp one on each upper shroud and hang the other end in the water. Joe Coquina C&C 35 MK I Worst lightning hit so far blew the VHF antenna off and ruined the battery switch with no other damage -----Original Message----- From: CnC-List [mailto:[email protected]] On Behalf Of Ryan Doyle via CnC-List Sent: Monday, July 25, 2016 10:00 To: [email protected] Cc: Ryan Doyle Subject: Stus-List Grounding a mast - 30mki Hey guys, Wondering if anyone can describe to me how they've ground their mast. I have a 1976 30mki and we got caught out in a very fast-moving t-storm this weekend and I realized I should have done this when I bought the boat last fall. My mast step is not original. It is a big, fat piece of mahogany - which I envision blasting apart if the mast took a direct strike. The only idea I've had is using a steel ring clamp to attach a terminal on a very large gauge wire (maybe 2 gauge?) to the bottom of the mast, then run this wire a foot or two aft and down into the bilge to a keel bolt where I would have a second ring clamp hold the wire's terminal to a keel bolt. I worry about how this would look and I also worry whether it would even be effective. Anyone have a better solution? Thanks in advance. Hope you're all having a wonderful sailing summer. Ryan Sent from my iPhone Sent from my iPhone _______________________________________________ This list is supported by the generous donations of our members. If you like what we do, please help us pay for our costs by donating. All Contributions are greatly appreciated! _______________________________________________ This list is supported by the generous donations of our members. If you like what we do, please help us pay for our costs by donating. All Contributions are greatly appreciated! _______________________________________________ This list is supported by the generous donations of our members. If you like what we do, please help us pay for our costs by donating. All Contributions are greatly appreciated!
_______________________________________________ This list is supported by the generous donations of our members. If you like what we do, please help us pay for our costs by donating. All Contributions are greatly appreciated!
