The Keel, Keel Lock, Keel Box and Keel Box Safety Issues.

The good part about Catalina 22 with the swing keel is that the keel itself can not present any structural problems - it is a cast piece of iron, and most probably a 20 ton truck can drive over it, and it would not bulge. The keel can rust (in fact, in my case there was considerable damage from rust to the trailing edge and in many parts on the leading edge and here and there).

When I was doing the overhaul of the keel, I took it down, grinded out the damaged areas and painted with special marine epoxy paint. I did not do any fairing, because it would be loss of time and is a rather lengthy process. I do not care in the least whether I would be doing 5.75 knots unfaired or 5.83 knots faired... The time gained during sailing will be lost 10 times over during the fairing process.

The original condition of the keel with the bronze pin.

I checked out the pin, and it was without slightest trace of damage. The only thing I did to the keel was to put a few layers of fiberglass cloth in the area of the bronze pivot pin in order to reduce lateral play.

The hangers and the bolts which attach them to the hull.

The keel through its bronze pin “hangs” in two hangers, which are attached by four bolts to the hull. These bolts, about 8 mm. in diameter, can fail and are the weakest link in the safety chain. I had to change them, which was a task of its own. Two came easily, and two broke off, so I had to take the boat to a mechanic who was able to extract them without damaging the threads (you cannot increase the diameter of bolts by doing an new thread, because the metal where the bolts go is not very thick). New bolts were fitted.

The much more complicated safety issue is the keel box itself: it is extremely flimsy structure, only 4 or 5 mm thick! I was surprised to find that when drilling a hole in it. It was not properly braced except for one small triangular insert on the port side with just 1.5 mm fiberglass tacking. When running down the wind with waves from behind, the upper part of the keel box was moving about 7 mm. to each side with each wave! So, the first thing I did was to strengthen the port side, because it did not involve doing any damage to the “beautiful” starboard liner. First, I built some thickness with fiberglass on the hull floor on the left from the keel box, about 7 – 8 mm. Then, I cut out two triangular supports from Chilean wood (20 mm thick) and epoxied them in. In addition, I epoxied a more inclined piece of wood in the rear. The wobbling in heavy sea became almost non-existent and barely noticeable (maybe 1-2 mm.). I also had to strengthen the existing locking bolt area.

The port side of the keel box after the modification. Originally, the Catalina had only the left-most support installed, the other two triangular supports and the square wood piece were installed by me.

After a couple of navigations and increasing the weight of the keel by 38 kilograms, I decided that it would be safer to strengthen the other side of the keel box, the starboard side. I cut out the liner on the starboard side, put in two inserts, one from styrofoam and the other from wood and built up thickness with fiberglass and epoxy.

I thought that the floor liner would need strengthening, but I discovered that it was resting on solid filler at least 20 mm. thick and very well bound to it, so that I decided to epoxy the reinforcement directly to the liner.

The starboard side of the keel box after the modification.

Keel Lock

There is another safety issue which always worried me: the possibility that the keel may slam back if the boat turtled. If that happened, there was no chance for the boat to righten itself.

The standard protection made by Catalina against it is the bolt on the port side. The keel is held loosely in its downward position by means of this single bolt which is tightened through the keel box and presses the keel to the other wall of the keel box. The bolt presses against the keel, but does not lock it, so that the keel can slide backwards when hitting something hard, and possibly when turtling over. It may have been a good idea for those who believe that ecosounder is not needed and feel their way to the shore with the keel… But, at high seas I would prefer to have a bullet-proof system for locking the keel down. In fact, the earliest hulls of Catalina had a through bolts but because many would-be sailors managed to mangle quickly the system (if you grounded the boat, the through bolt would usually bent and rip the keel box, requiring extensive repairs), Catalina replaced them with the sliding brake bolt.

The left bolt is a brake bolt, the right bolt is a stopper bolt.

So I decided to add two more bolts on the starboard side of the keel box. The idea was the following: the original bolt on port side and one of the new bolts on starboard side would enter the keel by about 15 mm. into holes drilled in the keel. That would virtually lock the keel dead, and two bolts would spread much better potential loads to the keel box in case of a moderate grounding, and the only way to move the keel would be to break completely the keel box. The second bolt on the starboard side would simply press on the keel and act as the original stopper bolt. So, when navigating close to shore, in safe places, lakes, and where there is a risk of ground contact, only that bolt would be tightened, and the other two would be completely unscrewed. When leaving for high seas, the two bolts would be tightened, locking the keel safely.

So a strip of stainless steel with two nuts was welded and then epoxied onto the keel box. In the area of the nuts, where the stresses are greatest, I have built up about 18 mm. thickness, and in other places the thickness was reduced to about 6 - 7 mm.