There are many fiberglass sail boats in the US that have bolt on ballast fin keels that have reached their end date. Fin keels, in contrast to traditional keels with the ballast attached as a long rectangle at the bottom, with questionable keel bolts render the sailboat dead to the open ocean. There are two options, lag bolts which you are considering but you should check out this https://www.catalinadirect.com/shop-by-boat/catalina-27/hull-deck/keel/keel-bolt-retrofit-kit-c-22-c-25-c-27/. For a different process that Mars Keels uses that melts the led keel and reinstalls the L or J bolt. It isn't cheap and I don't know if there is anyone in Europe who can do it. https://marskeel.com/keel-bolt-replacement/ 

Bert Quitzsch wrote:

Hello, I have drilled the holes into my leadkeel using a spiral drill for wood, lubricated with dishwashing Soap. You can‘t take Drills for metal because the material has to come out of the leadblock as quick as possible. Drill slowly.

Bert

Arne Kverneland wrote:

Just remember one important thing:
Lubricate the hole for every 2-3 cm, or you risk that the drill-bit gets stuck forever.
I once drilled in lead with a large electric drill (only on-off switch) and when the bit got stuck, the drill started rotating, and almost tore my hands out of their sockets. They hurt for days...

Arne

Anonymous wrote:

I once participated in casting a 2-ton lump of lead ballast for a long-keeled wooden boat. The casting went not entirely without incidents. Therefore, to be sure that the lead would not split, the boat-builder ran the keelbolts right through the ballast with countersunk heads or nuts on the outside. This worked perfectly well and still does, as far as I know.

Maybe that is the way to do it on Mehitabel too?

Arne

crew drilling the keel bolts for their project.  They did it by eye, as far as I can see, and the longest hole was 1.2m!  It came out straight, too!  They then used a special bit to cut a socket in the bottom, to recess the nuts and washers.  I'd need a jig , (or preferably an expert with a jig!) but would love to do it that way.  Five one-inch bronze bolts would do the job.  I plan to talk to some engineering shops about it eventually, but expect the lag-bolts will end up being the practical solution for a fin keeler.

Rainy Saturday night here with a gale blowing.  Tucked up in my cabin dreaming.  What I'd really like is to be offered a nice shed for a very modest rent that I can live in for a year or two, and build a wood-epoxy 26-footer that is a pure solo cruising machine.  It would be a very basic workboat, all painted ply, with watertight bulkheads and some foam floatation.  But I'm just dreaming...

If I was to proceed with converting Mehitabel to junk rig (rather than finding a smaller boat for this project), I will need to deal with the keel bolt question.  I'm wondering if anybody has direct experience with this issue?  My keel bolts are stainless j-bolts cast into the lead, so cannot be withdrawn and replaced.  They pass through a fore-and-aft, hardwood timber 'keelson' or stiffener that is heavily glassed into the bilge.  Because of the keel-stepped mast, and that I am the first live-aboard in 50 years, there is a long history of rainwater lying in the bilge and immersing the bolts.  The mild steel backing plates are badly rusted.  I have no idea what condition the bolts are in, especially where they pass through the timber.

Obviously, the backing plates need replacing, but I really should inspect the bolts.  Dropping the keel is the most obvious approach to inspection, but I have also heard of X-ray and ultrasound services.  I don't know how reliable they are.  As usual, the internet is full of conflicting advice, often from people with little first-hand experience.  If the keel bolts are compromised, I cannot replace them.

I could sister them, so I read, but how to do so is another divisive point.  There are two common approaches, to screw in silicon bronze lag bolts, like L. F. Herreschoff did, or to cut inspection ports in the side of the keel in the vicinity off the new bolt holes, and use nuts.  I'm told there is a fine art in this.  You fill the new vertical holes with water, then guess where they are located and drill small horizontal holes in the proximity.  When you find the keel bolt hole, water will leak out.  Then enlarge the hole into a port and happily fit nuts and washers to your bolts before refilling the ports with epoxy or whatever.

So, any advice from people who understand these things would be appreciated.