lead bulb attached to a cast iron keel.

srah1953 said:
Some boats (more upmarket ones) have a lead bulb attached to a cast iron keel. Anyone got an idea as to how they are attached to each other. Just curious
Thanks
Click to expand...

It would be nice to know wouldn't it.

I've got one but I think it's cast iron. In my specs it's specified as a "bomb". Does look like one I suppose.
 
I would assume that the iron keel has some kind of fixing structure at the bottom, and they cast the lead bulb around the iron keel.
 
Not a bulb but the Mickey Mouse Ear keel of our Sigma 38 had a lead bottom half, the join was never very visible but my recollection was that there were studs with the nuts accessed through lateral holes. The bulbed keel on our Finngulf was all lead with a slightly worrying inverted wineglass profile, quite narrow . Lead antimony alloys must be stronger than one imagines though it was never that difficult to punch a substantial hole in it.
 
Quandary said:
...... lead bottom half, the join was never very visible but my recollection was that there were studs with the nuts accessed through lateral holes. .....
Click to expand...

There was a thread on here that showed this. Slots in the cast iron part of the keel where the nuts that held the bulb on could be accessed. The slots were just filled with some filler material, iirc.
 
I once tried to buy an X119 with the original torpedo keel. I was a bit concerned by the keel though this was not the reason we did not buy it, more to do with resistance from my better half. However I do not recall any worries about the keel structure and she was out of the water when we looked at her, mainly concern about the likelyhood of entanglement. She was a lovely boat and at a keen price but much more racer than cruiser. Most of them now have replacement conventional lead bulbed keels.
 
I believe my Impala had a lead 'shoe' added to the bottom of the iron keel.
AIUI, the bottom of the iron bit was drilled and tapped, studs went through the lead to nuts in recesses in the bottom of the lead shoe?
But I never had it apart, so I'm not sure.
The lead shoe was maybe 4 or 6 inches deep?

Because the lead part is not very deep, there is not much leverage, the loads are much lower than the main keel bolts.
 
When I added a lead bulb to the bottom of the keel of my first Mischief 24 I drilled two holes through the cast iron keel and bolted the bulb on with stainless rods large washer and nuts recessed into the bulbs and then filled the holes with epoxy.
 
Quandary said:
that there were studs with the nuts accessed through lateral holes.
Click to expand...
When I was in Ijmuiden there was a 50 ft Grande Soliel surrounded in tarps. Underneath it could be seen that the lead bulb was hanging off the stub cast fin by over 50mm.
Judging by the lump carved out of the lead it had obviously hit an underwater obstruction VERY hard. The lead part had a number of stainless studs that went into the cast iron as described above. It could be seen that someone had already started to remove the filler in the sockets to access the nuts inside the sockets. Although the bulb had moved it still seemed secure so the studs had probably just been wrenched upwards in the lead but not enough to pull them right out. The aft most studs had moved the least. The forward ones the most. Interesting to note that there were no visible cracks on the outside round the fin root. Obviously that does not say what the inside was like, but I could not help thinking how strong the keel seemed - considering the large lump out of the lead
 
You must log in or register to reply here.

Other threads that may be of interest

Sea Change
Mini sandblaster for rust spots on keel?
2 3 4
Replies
63
Views
2K
Mister E
M
P
Essential pre purchase or even pre survey checks
2
Replies
28
Views
870
Refueler
Refueler

Share this page

Top