Keel Question

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Lady of the Lake
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Keel Question

Post by Lady of the Lake »

Lady of the Lake is on the hard getting new bottom paint. Good news is I found no water in the keels. Bad news is there were some minor blisters on the keels, but easy to repair. Now for the question. When sanding down the keels and repairing the blisters, it became evident that the keels are different from anything I had seen before. The top half of the keels are a different material than the bottom half which are fiberglass as expected. The top half seems to be more of a hard foam type material. Is this the material that allows the keels to be "sacrificial"? Once painted it all looks the same but I was surprised to see the 2 different materials. It is not just where too much fiberglass could have been sanded off, it is a straight line down each keel, looks original. Any ideas? James, your thoughts? Remember I have a very early hull, #15.

Thanks for any clarification,
Sam
Sam and Gina Densler
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PDQ36 Hull #15
Punta Gorda, FL
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Re: Keel Question

Post by PDQ-Dave »

I would venture a guess that the material you describe is light blue. IF this is the case then I'd further guess that it's fairing compound used to smooth out the keel to hull stub transition and any other imperfections. Fairing compound is usually polyester resin based and includes fillers (glass fibers, micro balloons etc) to make it thick for easy application and also easier to sand once it sets up. The catalyst for many fairing compounds is dark blue so that when you mix it with the usually white fairing compound the result is light blue. It's the light blue color that lets you know you have throughly mixed in the catalyst into the resin. I encountered some light blue filler that had a very different density than the fiberglass while working on the hull extension project thus the basis for my guess.
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Re: Keel Question

Post by Lady of the Lake »

Splashed Lady of the Lake today. Keels looked good. But a question. If these are sacrificial in the case of a hard grounding, then how are they strong enough to hold the boat on just the keels? There have been posts of 36s beached to clean bottoms and I have also seen Pat's Cat sitting at the dock at low tide with all of her weight on the keels. How is this possible if the keels are designed to break away. I have to tell you, after working on the keels and seeing the way they are mounted, I can not ever imagine my 36 sitting on her keels alone without me being very nervous. Any thoughts? Maybe a difference in later hulls?
Sam and Gina Densler
s/v Lady of the Lake
PDQ36 Hull #15
Punta Gorda, FL
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Re: Keel Question

Post by amytom »

Sam,

Could it just be the difference in the angle of the pressure? Sitting on the hard is just a compression force where as striking bottom at speed would be a shear force.

What did you find with your engines? Did you remove the lower units? What about the tilt brackets?


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Re: Keel Question

Post by Lady of the Lake »

Maybe so but they sure did not look strong enough to me. Not sure of the balance either, looked like it would be way too easy to tip forward or aft depending on loading. I am not trying it!

As for the motors, I decided to take the lower units off and apart just for PM. Everything looked good. Easier since the boat was high and dry. Forgot about the tilt levers until the boat was already back in the water. Looks like I am going under in the dink...
Sam and Gina Densler
s/v Lady of the Lake
PDQ36 Hull #15
Punta Gorda, FL
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Re: Keel Question

Post by Bob »

Turns out that my keels did have water in them, I just drilled into the trailing edge the first time. I do not see water in the keel as any concern unless hauled out in freezing climes. With regard to the resting of the hull on the keels the first boat I had (#32) was sitting for close to 3 yrs in the Texas sun on it's keels. All I noticed was the floorboard access panels rocked a little due to what I perceived as a slight flexing of the hull. When I put it in the water it corrected itself in a few days.
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Re: Keel Question

Post by Lady of the Lake »

So it was time for our first bottom job in SW Florida so we tried a new yard. Nice paint job (keels were getting some clean up and not yet painted in the pic) but I have never seen toe PDQ36 blocked in this manner. Goes against what the owners manual says but everything went well. See the pic and tell me what you think...
IMG_1348.JPG
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Sam and Gina Densler
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PDQ36 Hull #15
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Re: Keel Question

Post by SecondWind »

Sam, We were blocked like that several times when we were in Maryland. I didn't see any ill effects from it.
Terry Green
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Re: Keel Question

Post by thinwater »

Actually, the PDQ keels are intentionally place under the CG so that they can dry out. Look at them; they are CLEARLY too far forward for sailing performance.

Yes, I have had my PDQ 32 dry out on a beach once and she was quite stable.

----

To be sacrificial they simply have to be weaker than the hulls in shear. That's pretty strong.

Regarding blocking, the only problem I ever had was when they put to much pressure on one of the aft bulkheads; it was bending so I had to lower that jack (don't do what I do--I used to work for a rigging company).
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