"Grounding" the mast

[Stuart Gregory]

I have an old O'Day 22. The mast is stepped on deck and is not grounded to the keel. Problem is that there is no access to the keelbolts. I'd like to put in a below the waterline copper thru hull fitting and run a copper wire to it from the mast. But I'm not planning on taking it out of the water until next winter. Can anyone recommend an effective remedy?Thanks much.

 

[Debra B]

lightning strike might take out a copper thru-hull

If that is your only exit, then it may melt-down in a lightning strike.A temporary palative is to ground the standing rigging to the water - a large diameter copper pipe with some large holes drilled in it and a jumper cable. (You can buy these ready made)

 

[Mark]

Give it away

I am sure that there a few knowledgeable people out there who will confirm that for a ground "wire" to be effective it would have to be a foot thick.When lightening strikes the amount of current will blow away any chain or copper wires you run.

 

[Dave]

Anodize

Aluminum parts are anodized to prevent oxidation. This essentially is an oxide layer that acts as a barrier to further oxidation by preventing the substrate material from exposure to the atmosphere. Anodize is a completely non-conductive surface. Aluminum oxide is a typical abrasive used to make grinding wheels, try running a current through one. The mast will still conduct as only the surface is non-conductive. My point in this discussion is anything you attach to the mast to try to electrically bond for a ground application must connect to the aluminum substrate to be an effective ground. Make sure you do a conductivity check on your circuit when you finish the project.Dave

 

[Carl Lebo]

I thought

that the idea was to dissapate the electrical charge, not to direct the lightning. In other words, prevent (or reduce) the chance of a strike.

 

[MArk]

Mast Grounding

Link below

 

[tim donley]

strikeshield

Thanks Mark, this link is the most informative for all to read. I'm familiar with the program at the University of Florida and the Sea Grant Another sit to visit is www.strikeshield.com. Yes they manufacture dissipation/grounding equipment but they provide a wealth of information to help understand this phonemon.DO NOT BOND MAST AND RIGGING TO THRU HULLS unless you think you want large underwater view ports. Between these two links( University of Florida & Strikeshield) you will become as informed as much as possible. An old marine electrician I worked with many years ago(Johnny Amsden r.i.p.)once said "the only people who really know any thing about lightning strikes are dead".Lets not become victims of our own missinfomation & "dock talk experts". Go to these sites and become informed and remind dockside experts to do the same.