Lightning Damage.. HELP

[seatheworld]

My 65 footer was struck by lightning, has anyone heard or seen fiberglass that has softened from a lightning strike. The resin is not burnt thru, but it is discolored. a 3 foot area near the keel is oilcaned. and the shaft is bound, keel is pushing up into the hull.

Thanks

[Mirari]

Most likely you have massive delamination. Likely caused by the instant steaming of moisture in the laminate when the lighting strike exited into the sea. Did the boat have a lightning grounding system?

[seatheworld]

Yes, all thru hulls were bonded, it also blew out the fiberglass in those areas too. Will thermal imaging tell me anything?


Thanks Jim

[erps]

Will thermal imaging tell me anything?

I don't think so, as that only shows current temperature differences. Geez, this sounds awful though. Until your post, I just worried about electronics getting toasted. Now I have something new to worry about.

[hellosailor]

Jim, bonds are to prevent galvanic problems, not to channel lightning.

You need to have the boat hauled and surveyed by a professional, and if you have hull insurance place a claim immediately.

Other folks who have suffered strikes have reported everything from "pinholes all along the keel" to seized prop shafts and blown electronics in any conceivable corner of the boat.

Yes, a jillion volts passing through fiberglass can melt the resin and glass, or superheat any fluid that was inside it.

[Mirari]

Spending a few hundred dollars and some time putting a lightning grounding system together is probably one of the best investments you can make for your boat, unless of course you have good insurance and don't really care.

[kd3pc]

Originally Posted by Mirari

Spending a few hundred dollars and some time putting a lightning grounding system together is probably one of the best investments you can make for your boat, unless of course you have good insurance and don't really care.

proven time and time again to be of absolutely no use in a direct lightning strike to the boat and cost way more than a "few hundred dollars" while they will still provide bypass and shortest path to ground, there is no way to guarantee that the strike will follow it...

as the OP finds, and will find, lightning can cause moisture anywhere to become volatile regardless of where it is, or how "dry" we may think the material is.

Many of these systems are almost as useful as ultra sonic bottom critter repellent.

Just the PL259 strike/arc boxes for ham radio and vhf coax are almost a hundred dollars each, and that is where you can take them to an earth ground. Appropriate ground rod and bussing are thousands for the material and installation....I just spent over $700 on a 50 amp, 100', three conductor copper with ground.....just the cable....as copper is $$$. Not to mention the tower grounding.. again this is on the land, where you can do what you want, cadweld connections and the like.

Look up polyphaser or Roger Block for more, accurate information. His designs are used by the DOD and many commercial tower erectors, with great success.

You can certainly find someone to do this kind of work, but I would still have great insurance.

Yes, I am a licensed electrician, and a ham radio operator, FWIW.

[hellosailor]

"proven time and time again to be of absolutely no use"
I'd have to take issue with that. I'd say "proven time and time again that it may be of some help" in any lightning strike.
And for most sailboats, with a typical external lead keel, the only investment that is needed is to run a heavy cable or strap from the mast base to the keel bolts "encouraging" the strike to take that direct path down and out.
It may not protect the boat from ALL damage, but it greatly increases the odds of MINIMIZING damage from flashovers and other routes.
Three to six feet of heavy cable or busbar, a couple of good bolts, no big investment no "systems" or polyphasers needed. You don't need arc devices like that when you are not trying to protect antenna lines. On a boat, all you need to do is remember to UNPLUG the radio antenna when not in use. (And preferably ground it at the mast.) Or add the polyphaser. Not so hard to unplug and secure the cable when you leave the boat.

[kd3pc]

Originally Posted by hellosailor

"proven time and time again to be of absolutely no use"
I'd have to take issue with that. I'd say "proven time and time again that it may be of some help" in any lightning strike.
And for most sailboats, with a typical external lead keel, the only investment that is needed is to run a heavy cable or strap from the mast base to the keel bolts "encouraging" the strike to take that direct path down and out.
It may not protect the boat from ALL damage, but it greatly increases the odds of MINIMIZING damage from flashovers and other routes.
Three to six feet of heavy cable or busbar, a couple of good bolts, no big investment no "systems" or polyphasers needed. You don't need arc devices like that when you are not trying to protect antenna lines. On a boat, all you need to do is remember to UNPLUG the radio antenna when not in use. (And preferably ground it at the mast.) Or add the polyphaser. Not so hard to unplug and secure the cable when you leave the boat.

HelloSailor and I Obviously disagree, but you are all free to do what you feel to mitigate. I am only offering my experience (as does he), but I would point you to my complete thought....
"proven time and time again to be of absolutely no use in a direct lightning strike to the boat "

Further, you can disconnect the VHF if you like, but that does nothing to remove that highest, shortest path to ground i.e the coaxial cable - and the salon/nav, where lots of tasty electronics, direct paths to the engine/battery and such are but a MM away, and which will likely be the first boat part to throw lightning back to the sky and establish a strike path. The cable is still connected to the antenna, follows the spar direct to the interior...and it will find a place to discharge. False action 100%

If the big bussing of cables, questionable connections and such make you more comfortable, by all means do so. To be of any use, they need to be sized, installed and maintained in pristine condition with NO mechanical splices, else those will explode.

Again I would encourage you to research lightning strikes as presented by BoatUS, Panbo and NFPA, a few years back and point you to those systems designers who have all but proven that the "highest, sharpest point" that mid describes is no longer valid and has been proven such by quite a bit of research. NFPA and those designers agree that a "cage" offers far more protection than the spar being grounded to your keel, maybe as he describes it as a DIY...for some DIY pictures of what does NOT work, simply google aluminum boats and lightning, or ham radio/chimneys/lightning strike

YMMV,

[hellosailor]

"Further, you can disconnect the VHF if you like, but that does nothing to remove that highest, shortest path to ground i.e the coaxial cable - and the salon/nav, where lots of tasty electronics, direct paths to the engine/battery and such are but a MM away,"

Which is why I said to disconnect it and ground it preferably at the mast.

That keeps the path well more than a few mm's away from all the other wiring. There may still be an inductive pulse thorugh the lighting circuits from the mast, but again the idea is mitigation--not ensurance.

The same way that many hams take their antenna cables to a bulkhead in a wall or windowsill, and before a storm they ground everything at the bulkhead, disconnecting and separating it all from the rest of the wiring tha comes further into the room.

Yes, I know, the arc can still reach out and touch some. Again, the goal is to stack the odds, and breaking circuits and grounding them does that. Inexpensively.

For complete lightning protection, all you need to do is sink or invert the boat. There may be other issues relating to that, but sinking the boat will pretty much protect it from strikes. Will protect it up upstrokes, will protect it from the primary charge on downstrokes.