Pearson Boats - Common Systems > Standing & Running Rigging and Fitting/Tuning

Another new owner and a question - Lightning ground?

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Carolina Dog:
Hi all. I purchased Lucky Dog in May in Oriental NC. Totally pleased with the boat. I have already replaced running rigging, Plumbing, Engine parts and Electrical. I have the Seaward 3121 stove at the house for rebuild (really I am done but considering new guts to bring it to code). LOTS to do but what fun. I have sailed since third grade when my pops brought home a home made El Toro dinghy and stood on the dock shouting instructions. Been infected ever since. After a lot of research I selected the 323 as my next boat. The boat is in Belhaven, NC but as as soon as I replace the thru hulls and paint the bottom I am moving her to Georgetown, SC which puts me right down the road from Frayed Knot. I am having chainplates made and will replace them along with the mast step when I pull her in October. So much of the things I am doing and my knowledge base has been a product of this site. Thanks to the group for that! Hopefully I will be able to contribute a little something to this site.

My question is: Is anybody grounded from the mast to the lag bolts holding down the mast step?
Is this a reasonable thing to do? I read a research article from the coast guard site that suggests a lightening strike to ground through the lead keel would possibly blow off fiberglass from the keel but would not hole the boat. Any thoughts?

Not sure how to insert an image so I will try an attachment... Cheers, Marcus of Lucky Dog

Dragonstar:
Hi Marcus,

First off, sorry to say that we can't weigh in on your question about grounding. However, we were looking through posts about chainplates and came across your note. As new Pearson 323 owners (3 days!), we've also found that at least one of our chainplates needs to be replaced: the forward lower shroud on the port side was completely corroded through at deck level.

You mentioned having your chainplates fabricated, so would you happen to still have the specs for them?

Thanks,

Cody & Angela of Dragonstar

Dolce_Vita:
Our 323's shroud chainplates are pretty simple and easily accessible.

I replaced one of the aft-lowers after finding the beginnings of a crack when inspecting it.

All of the chainplates are fabbed from straight 1/4" x 1 1/2" bar stock.
The ones for the fore and aft lower shrouds are just over 12" long while the center uppers are about 14" long.
The exact length is not critical.

I had the new lower fabbed from 316 stainless and had it cut to 12".  The bolthole spacings for the below deck fastenings are somewhat arbitrary, as they appear to have been hand drilled.  I simply gave the old one to my SS fab guy and told him to use it as a template for the new one.

One thing I noiticed when disassembling them was that the fastening bolts were originally inserted from the fiberglass side such that the chainplates rested on the bolt's threads.  Mechanical engineers will tell you that this is a bad thing to do, as it creates stress risers that are potential failure points.  I reversed the bolts so that they went through the chainplate first, then through the fiberglass so that the chainplate rested on the unthreaded shoulder of the bolt.

You can safely replace the chainplates one-at-a-time with the mast up.  Rig a halyard as a temp shroud replacement when doing each of the uppers.

Dolce_Vita:

--- Quote from: Carolina Dog on August 10, 2013, 10:42:15 AM ---...My question is: Is anybody grounded from the mast to the lag bolts holding down the mast step?
Is this a reasonable thing to do? I read a research article from the coast guard site that suggests a lightening strike to ground through the lead keel would possibly blow off fiberglass from the keel but would not hole the boat. Any thoughts?...
--- End quote ---

Marcus,

  Mine came that way, with a large heavy green bonding wire attached to one of the lagbolts holding down the mast step.  I kept it that way when I replaced the mast step.  Also,  the upper shroud chainplates and all through hulls are similarly bonded.

As for whether its a good thing to do or not, I don't really know.  My research shows that there are recommendations all over the map regarding bonding and lightning "protection", with no clear conclusions.  There seems (by my interpretation) to be a small amount of consensus that bonding may slightly increase the probability of a strike while slightly decreasing the possible damage, while isolating the mast may slightly decrease the probability of a strike while slightly increasing the possible damage.

I take it all with a grain of salt. The damned lightning's going to do as it pleases!  ;)  As always, YMMV.

Frayed Knot:
Carolina Dog Welcome to the hood.  Will you be living in Georgetown or close by?  I love working on my boat and I think that's part of the reason I got her.  Let me tell you I truly love her.  Have sailed every weekend  from the end of May to now.  Might be going to try to race her this weekend.  I know her hull speed is 7 something but she will do 7 to high 8 in 10 to 15 knots feels fast to me...Anyway welcome, if you need anything be glad to help.   Dick Martin (Frayed Knot)

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