Keel repair

Oct 17, 2025
10
boomaroo 22 22 Sydney
Have a boomaroo 22 Australia (Catalina) and the swing keel pivot hole is completely rusted. There seems to be 2 options.
1- reweld the cast iron into a solid piece and drill a 1inch hole for the pivot pin,
2- cut out the hole and insert a new piece of metal that is bolted into the keel.
3- make a sort of sleeve that fits directly over the pivot hole but larger , maybe 150cm which gets screwed into the keel.

Comments pls.
 

Attachments

dLj

.
Mar 23, 2017
4,618
Belliure 41 Back in the Chesapeake
It may be hard to weld that hole shut as you don't know what that piece is make from. It would be likely a cast ductile iron - but you would need to know the actual alloy or you are just throwing darts at the wall blindfolded... You could braze a bronze insert into it. That may well be better than welding in any case. But the hole is quite damaged, you would have to a fair but of prep work to do that.

Wrapping it as you've described would also work. I think that is likely the easiest method to use.

dj
 
Oct 17, 2025
10
boomaroo 22 22 Sydney
I feel welding a new hole would be quite hard for even the best welder,it is cast iron.
So my idea would be to use SS plate maybe 3mm and drill screw inserts 6mm into the keel then screw the cover that has the pivot tube pre welded at exactly 90 deg.. over the damaged hole.. if I make it slightly undersize I can remove some of the keel material so that when installed it is flush with the rest of keel... But b4 that I would encapsulate the keel in epoxy/ fibreglass, one layer of glass only, then fair it to a foil shape.
if I put the SS capping over the finished keel then there is a chance the screw holes may allow water to get under the glass.
If I put the capping directly onto the cast iron screwed in then epoxy/ glass and fair over the whole thing it might be more water tight.
Can you fibreglass over SS..if I rough it up ?