Todd, I'm considering buying a '68 Excalibur for a solo trip to Hawaii. I've sailed them before when I used to teach sailing up here in the SF Bay Area. There are multiple reasons that I think the boat is a good fit for me, but one big concern...
There's a thread here on SailNet about Excaliburs and keel flex, and I've read it. I'd love to hear more from you or anybody else who has experienced it, and even better...have fixed it.
I'm competent enough with fiberglass work to put down a couple of layers of roving and mat at the turn of the bilge to stiffen her up, if that's what it takes.
Alan and I already talked on the phone, so we've had a chance to talk about things. I was timed out when I tried to respond earlier after composing a long response. I'll try this again just so my opinion about the dreaded Excalibur keel flex is made public. Again, this is my opinion, based on my research and experience. I am not a naval engineer. I studied English in college and manage a large automotive Service Center.
The subject is brought up from time to time and usually it is either by one individual or as a result of something that was posted by the same individual and then read by someone else. The keel itself does not flex on the Excalibur 26. The keel is a very thick encapsulated fiberglass assembly that is integral with the hull sides. It is filled with ballast material (lead, pig iron, concrete) that makes it very rigid. It can not flex. The concern is that the stiff keel puts an excessive load on the hull bottom in the curved area where the hull bottom meets the hull sides, weakening the fiberglass over time, allowing the keel itself to move.
In my experience, this is completely wrong. In my boat and others that I have been able to look at, it is possible -- if you stand with your legs straddling the bilge area, about 18" up on each side from the center line, and rock the boat from side to side -- to make the keel appear to move from side to side as each hull side is loaded and unloaded. It looks as though the keel itself is moving. It would be alarming if you didn't notice that as you are doing this there is also an opposing movement from the upper hull side on the opposite side of the boat. The hull itself is flexing as it is loaded and unloaded, not the keel, and not the area of transition between the hull bottom and sides.
Aircraft wings are designed to flex because the loads imposed on them are tremendous and the act of damping the load on the wing, through flexing, is safer than building a rigid wing that would not move until it reached the (lower) absolute limits of the construction and then broke off. Hull flexing, while not ideal when absolute speed is the goal, is safe. I don't know if Mr. Crealock intentionally penned a boat with a flexible hull or if it was just a result of his design. He was pretty savvy in knowing what his boats were capable of but, unfortunately, we can't ask him. Today, a design would be drawn within computer software and stress tests on the digital design would determine the characteristics of the hull -- strength and rigidity or flexibility.
It was spoken of that a previous owner was quoted a price exceeding the value of the boat in order to "fix" the floppy keel. In my opinion, this was either a case of a shipyard that didn't understand the design of the Excalibur 26 or a case of one hoping to oversell repairs on the boat. The layup of the fiberglass on the Excalibur is very thick, very strong and, at least on my boat, very high quality. It was was not chopped, blown-in glass.
My hull had sheet after sheet of glass built up one layer after another. The fiberglass in the lower hull area was in exceptionally good condition and showed absolutely no signs of weakening by right to left movement of the keel. Others, Wayfarer and Islander built boats that I've seen, were similarly built.
If an Excalibur owner wants to take the time to reinforce the bilge area, he or she can. I, however, don't think it's necessary on an otherwise solid boat. No amount of additional glass in the bilge area, or even above it, is going to completely eliminate the hull flexing that makes it appear to have a loose keel.
To end here, I'd challenge anyone to use whatever resources that are available to them to find a first-hand or documented case of an Excalibur 26 losing its keel. There aren't any. I've spent hours and hours looking for anyone who has actually lost a keel or been aboard an Excalibur 26 that did. The San Francisco Bay has claimed its share of boats and one of them is an Excalibur 26. It, however, struck debris and is still on the bottom of the bay as a result of its breeched hull. The keel is likely still attached.