Attaching lightning ground wire to keel bolt, need workaround.

[OrangeCrush]

Hey all,

I'm replacing some of my keel bolts, and I need to reattach the lightning ground wire that I installed previously. The wire is size 4/0 AWG and the keel bolt diameter is 5/8". Unfortunately nobody seems to make a terminal or grounding in this size. I could take a 1/2" stud size terminal and drill it out, but that would leave me without much metal for the nut to sit on. I had a clamping battery terminal connector on it before, but that won't be possible if I seal up the bolts well with epoxy like I need to.

Any idea on a different connector that would work for this application, or a way to fashion it myself? I was thinking of making it out of some thick copper sheeting, but I'm not sure if I'm losing much without the tinned coating, or by crimping it on myself like that.

Any thoughts? Thanks!

Jack

[Beausoleil]

You can fabricate a tab from 3/16" or 1/4" stainless steel plate, 2" x 2 or 3" long. Drill a 5/8" hole for the keel bolt and a 15/32" hole that can be tapped for a 1/2" bolt. That's what we did to bond our chain plates and our grounding strips.

[OrangeCrush]

How did you attach the wire to the tapped hole?

[Beausoleil]

Originally Posted by OrangeCrush

How did you attach the wire to the tapped hole?

Crimp lug with a 1/2" bolt hole. I made sure the bolts were long enough to be able to have a lock washer and bolt threaded on after - a bit overkill in normal situations, but I reasoned that with the bolt hole threaded I'd have double the surface area to transfer current in a lightning strike.

So, bolt thru cable lug, screwed into tapped hole in tab, backed with lock washer and nut. If you want even more peace of mind, you can tap the hole for the keel bolt, too.

[OrangeCrush]

I think that could work for me, thanks!

[nhschneider]

I had a friend who eschewed the use of crimp-on or solder-on terminals or lugs. Instead, he would flatten out the strands of wire, heavily tin them and then drill a hole of the required size right through the cable itself. He would then add length of adhesive-lined shrink tube to seal between the cable's insulation and the copper strands. This meant that now the wire - and not a terminal - was bolted to it's connection. Its kind of a time-consuming process but leaves no room for a terminal to fail. This guy had terrific hand-eye coordination and all of his work came out looking like art sculptures.

Fair winds and calm seas.