Masthead replacement on Ericson 29

[escapade]

why the copper?

I don't really see any advantage to running the copper wire inside the mast. A) Aluminum is an excellent conductor of electricity and you have lots of it available.
B) The voltages you will experience with a lightening strike will seek the shortest path to earth (ground) regardless of conductor type.
C) The dissimilar materials (copper/alum) will create a lot of corrosion where they meet.
Of the boats around here (Michigan) that have been hit by lightening usually only loose their electronics. I've read enough to decide that none of the experts can definitvely give you a foolproof method to avoid/minimize a lightening strike. They ALL will admit (in the fine print) that there is little you can do if it's really big lightening bolt. Your two options are to try to not make yourself a target (no grounding) or to try to bleed off the potential to try to avoid a hit (lightening grounding). Both methods work sometimes.
The surest thing is to buy good insurance and pray when it storms! BTW, I like internal halyards. Keeps the sun off half the halyard & when run to the pulpit a really easy way to stop halyard slap (I hated bungee cords!!!). Some of the older masts had sponges stuffed up inside to stop the wiring from slapping. You may need to fish them out to run your conduit & drop your new halyards. Makes a professional looking install though, IMHO.
Have fun & sail fast
Bud E34 "Escapade"

 

[NateHanson]

oops.

I meant to ask how far you've spaced the rivets in your conduit.

Nate

 

[maggie-k]

Hi Nate rivets every 3-4 feet is normal

 

[NateHanson]

Thanks Eric. Did you put a Tee in the conduit at the level of the spreaders, for the steaming-light/decklight wires? Or did you use two sections of conduit? Some other solution?

 

[maggie-k]

HI Nate for the steaming light and deck light I like the combo units. For an exit you finish attaching the conduit drill threw the mast into the conduit smooth the hole with a file , fish threw the wiring and seal the exit with Sikaflex I hope that helps
Eric

 

[NateHanson]

Yeah, Sounds good. I've already got a hole in the leading edge of the mast for my deck/steaming light unit, and I'll have to see if I can put the conduit there. Otherwise I'll make a new hole for the wire exit at that point so I can fish directly into the conduit.

 

[jkenan]

Escapade,

I completely agree with you on the point there is little you can do when faced with a direct hit by a strong lighning strike, expect for paying the premiums on an adequate insurance policy. Lots of power, there...

Because of the prevelance of thunderstorms around here (look at any May-Oct weather forcast for coastal NC, and 93% of the time it will include the word 'Thunderstorms'), combined with my first experience being in many of them, I firmly believe some precaution should be taken, especially when my family is aboard. I guess it boils down to two options in my mind:
1) Go with as robust a ground as can be reasonably built, or
2) Go with as as robust an ion dissipation system as current technology offers.

My only problem with the ion dissipation system (and there is no concete evidence or research to back this up, just a gut feeling) is that when the boat (usually by the mast) is not an adequate ground, me holding the helm (stainless) connected to a rudderpost (stainless) may provide a reasonable alternative as a direct path to ground. I'm out there, so it's no different than standing on a golf course in a storm (remember Caddyshack? Yikes.)

So for me, robust grounding it will be. Copper is a better conductor than aluminum, and measures can be taken to insure the copper is not in contact with the aluminum. Down the mast, thru the cabin, connected to a copper plate mounted to the hull exterior near the keel.

Check out the following URL on lightning precaution (it also offers discussion on ion dissipation, so the choice is up to the individual):

http://www.strikeshield.com/lightningground.html

There are many schools of thought, and like many things in life, there is no right answer. I'm open to discussion.

Cheers,

 

[simdim]

Maggie-k,
When you dropt your halyards inside the mast - did you have to trat the 2 openings at the mast top with any sort of sleeve? Also have you replaced the sheaves or just turned the existing once? I am agonizing over external vs internal for my replacement halyards

 

[Guy Stevens]

Internal

Internal halyards are a dream come true. Get rid of those old sheaves and put in something that really rolls and makes life easier. This is a simple very big upgrade if you have the mast down.

Garhauer makes roller bearing sheaves for the mast head that will fit your masthead.

Shaefer makes some stainless steel exit plates for the bottom end of the halyards.

Have fun!

Guy