Re: Thanks to Everyone -- Re: Keel Flex

...whoops, sorry to the group... I have not been responding to the group because I been hitting the wrong respond button. To recap some of what i said directly to Brad, the keel movement is a complex issue. Most of the movement is in the floor/hull not the keel on the cals with the molded in keels. You can go on just about any cal 29 and 2-27, stand over the keel in the cabin and shift your weight on your feet and get the keel to flop around quite a bit. I have done this in a few boats, they all have done it. There are a couple of contributing factors to the keel flex. One is that the polyester laminates have lost about 1/2 of the strength they had when they are were new. A second reason for the flex is that the hull skill is relatively thin in relation to the loads, probably around 1/4 inch. In my opinion, if you really want to stiffen it, you need to grind/cut the cabin floor tray out around the keel at least a foot either side of the keel. Once that is done, I would add glass to the hull floor and take it down to the lead and back the other side. Once that is done, I would laminate 1/2" mahogany across the floor going over the top of the keel and then I would glass heavily over that. I would also be sure to taper the wood as it goes out away from the keel so I would not create a hard spot too quickly in the hull. Based on what I have said above, fixing mine is a job I am putting off. Interestingly, while I can stand over the keel and make it wobble and see the floor/keel move, sailing upwind in 3 foot chop does not make the floor more. If I get a chance in the next couple of weeks, I will make video of it and show everyone. Jim Cal 29 sailor

I inserted a few comments…. On Oct 13, 2013, at 10:29 AM, "sailor7312 ." <sa… [at] gmail.com> wrote: > > > ...whoops, sorry to the group... I have not been responding to the group because I been hitting the wrong respond button. To recap some of what i said directly to Brad, the keel movement is a complex issue. Most of the movement is in the floor/hull not the keel on the cals with the molded in keels. You can go on just about any cal 29 and 2-27, stand over the keel in the cabin and shift your weight on your feet and get the keel to flop around quite a bit. I have done this in a few boats, they all have done it. Mariposa had a beam replacement. With the beam removed, I could stand on the starboard cockpit coamings and make her twist back and forth out of sink so that the foredeck was going one way and the transom the other. Pretty funny. Replacing the beam and main bulkhead stopped this twisting, squirming dead, but the keel continued to flop as Jim describes. At anchor on a calm morning with the tiniest swell motions, I could lay in my bunk and feel the keel wobble. One morning I awoke to a lazy swell and when the boat would roll one way and start back the other, I could hear a pretty loud Cracking sound under the port quarter berth. It turned out that one of the 1X2 support pieces broke loose and I had to rebuild the framing and plywood structure around the step and quarter berth. I blame this on the poor tabbing which had broken loose around the floor pan. > > There are a couple of contributing factors to the keel flex. One is that the polyester laminates have lost about 1/2 of the strength they had when they are were new. A second reason for the flex is that the hull skill is relatively thin in relation to the loads, probably around 1/4 inch. I agree with this whole-heartedly, but I was surprised to find that when I drilled a plug through the hull about 10" above the turn of the keel (on the flat bottom of the boat) the layup was at least 1" thick. It tapers pretty fast in both directions, because when I filled the hole that the original knot-log transducer sat in in the side of the keel above the lead plug, it was only about 5/16- 3/8" thick. The hull is certainly not much more than 1/4" on the cabin sides and probably down the topsides for a ways. > > In my opinion, if you really want to stiffen it, you need to grind/cut the cabin floor tray out around the keel at least a foot either side of the keel. Once that is done, I would add glass to the hull floor and take it down to the lead and back the other side. > Once that is done, I would laminate 1/2" mahogany across the floor going over the top of the keel and then I would glass heavily over that. I would also be sure to taper the wood as it goes out away from the keel so I would not create a hard spot too quickly in the hull. Pretty close to what I did, though I cut the floor pan all the way back to where it turns vertical under the cabinet and settee fronts. There was a huge oily and soggy mess under there that I'm glad I removed. Lots of weight and mess and lots of work. > > Based on what I have said above, fixing mine is a job I am putting off. > Interestingly, while I can stand over the keel and make it wobble and see the floor/keel move, sailing upwind in 3 foot chop does not make the floor more. > Interesting. Not sure I understand this, excel that if the keel is under load it would I suppose stiffen up and resist. Wilkie > If I get a chance in the next couple of weeks, I will make video of it and show everyone. > > > Jim > Cal 29 sailor > > > > >