Keel Bedding Survey

DaveBMusik · March 14, 2024, 06:25:02 PM

After removing the wood from my keel stub and repairing with layers of fiberglass, I dropped my keel to check the keel bolts but found them fine. I rebedded with 5200 (don't think there will be a problem in the future LOL) and put a couple layers of fiberglass around the keel seam.

Indian Falls · March 16, 2024, 05:46:02 PM

I did mine 13 years ago with 5200. No leaks. No smile. I however, did not refair the joint all the way around to make it pretty. I wanted to wait to see if I had success and to really let the stuff settle. Then another 11 years went by. I just put a little fresh VC-17 on it and make plans for next year. My procedure is in the tech wiki. The rust is from the iron "cast in lead" lifting points. The smile in my own opinion was from not enough glue in there in the first place and too much backstay tension coupled with keel bolts that had never been checked for torque.

http://c34.org/bbs/index.php/topic,6842.0.html

Ron Hill · March 17, 2024, 03:23:06 PM

dan : Disagree with you on the cause of the smile. I talked to the factory many years ago and they recommend that the boat be blocked with 75% of the weight on the jack stands/cradle and 25% of the weight on the nose of the keel. Also VERY important to get the jack stand pads on the bulkhead!!

A few thoughts

pbyrne · April 05, 2024, 06:48:06 PM

Quote from: Ron Hill on March 17, 2024, 03:23:06 PMdan : Disagree with you on the cause of the smile. I talked to the factory many years ago and they recommend that the boat be blocked with 75% of the weight on the jack stands/cradle and 25% of the weight on the nose of the keel. Also VERY important to get the jack stand pads on the bulkhead!!

A few thoughts

Ron, do you think this could be the cause of the fairing flaking off in my other thread? Sorry to hijack a bit... hopefully you know what I'm referring to Ron!

KWKloeber · April 09, 2024, 08:33:56 PM

I have for a long time disagreed with the thought (Catalina factory fantasy) that smiles are due to the blocking.

You have two planks that do NOT bend (the flat top surface of a hefty lead keel) AND a box beam constructed in the bilge stub. You are NOT going to bend the keel stub by shifting more or less weight forward or aft on the keel. For a crack to open, on one end the non-bending beams would need to open up, which creates a "V" to the ether end of the non-bending beam. It doesn't happen.

Besides, what happens to the "tender joint" (that according to CTY cannot resist being loaded by so-called mis-blocking it) when the keel is NOT supported (i.e., with (literally) tons of stress on it, while being kicked to and fro and back and forth while tacking and crashing through swells while heeled?
That doesn't create more dynamic stress on the joint than statically loading it (by so-called mis-blocking it)?

Ron Hill · April 11, 2024, 02:48:05 PM

Guys : I've heard Gerry Douglas say a number of times, "You have never heard of a keel falling off a Catalina Sail Boat"!!

A thought

girmann · April 24, 2024, 04:58:27 PM

Ron,

I'm not one to disagree with you and your experience, but the mechanical drawing from Catalina shows blocking only on the front of the wing keel. Mine is a Mk.II, so there might be a difference, but for Mk.II wing keels, all the weight should be on the front of the keel only. Next time I'm down at the boat, I'll take a picture.

Mark

Quote from: Ron Hill on March 17, 2024, 03:23:06 PMdan : Disagree with you on the cause of the smile. I talked to the factory many years ago and they recommend that the boat be blocked with 75% of the weight on the jack stands/cradle and 25% of the weight on the nose of the keel. Also VERY important to get the jack stand pads on the bulkhead!!

A few thoughts

KWKloeber · April 24, 2024, 06:56:21 PM

Quote from: girmann on April 24, 2024, 04:58:27 PMall the weight should be on the front of the keel only.

Quote from: Ron Hill on March 17, 2024, 03:23:06 PMblocked with.... 25% of the weight on the nose of the keel.

Mark,
You didn't say what % of weight should be on pads vs the keel, but, above, parsing out the pertinent information ... You both are saying the same thing.

Weight should be supported at the nose (ie., forward part of) the keel. ***

I trust that you are not saying there should be no weight on pads (be it jack stands or a cradle)???

PS: ***Do not read into this that I buy into CTY's fantasy explanation of what causes a smile.

girmann · April 24, 2024, 07:10:17 PM

You are absolutely right. I (mis)read his post three times before answering and still got it wrong. Thanks for the correction. I had this fight with the yard last fall and couldn't see what he was actually saying.

Quote from: KWKloeber on April 24, 2024, 06:56:21 PM
Quote from: girmann on April 24, 2024, 04:58:27 PMall the weight should be on the front of the keel only.

Quote from: Ron Hill on March 17, 2024, 03:23:06 PMblocked with.... 25% of the weight on the nose of the keel.

Mark,
You didn't say what % of weight should be on pads vs the keel, but, above, parsing out the pertinent information ... You both are saying the same thing.

Weight should be supported at the nose (ie., forward part of) the keel. ***

I trust that you are not saying there should be no weight on pads (be it jack stands or a cradle)???

PS: ***Do not read into this I buy into CTY's fantasy explanation of what causes a smile.

High Current · April 24, 2024, 07:53:13 PM

Quote from: KWKloeber on April 09, 2024, 08:33:56 PMI have for a long time disagreed with the thought (Catalina factory fantasy) that smiles are due to the blocking.

Actually I buy it. My old hunter had a smile too. I filled/faired with G/flex and sailed for a season. At haul out, hanging in the travelift slings, I was eager to see how it had held up. Perfect. An hour later she was on the stands and the seam had been cracked open.

KWKloeber · April 24, 2024, 08:22:35 PM

Quote from: High Current on April 24, 2024, 07:53:13 PM
Quote from: KWKloeber on April 09, 2024, 08:33:56 PMI have for a long time disagreed with the thought (Catalina factory fantasy) that smiles are due to the blocking.

Actually I buy it. My old hunter had a smile too. I filled/faired with G/flex and sailed for a season. At haul out, hanging in the travelift slings, I was eager to see how it had held up. Perfect. An hour later she was on the stands and the seam had been cracked open.

But, that does not prove the original cause of the smile. Just that a patch job didn't work.

Coincidence is not valid proof of causation.

Again, anyone who can logically explain how, using engineering principles of statics and mechanics, two unbendable beams can magically be made to bend, all while the same (and higher) stresses occur on the keel/joint (while sailing) and that does NOT cause the joint to open -- Have at it.

KWKloeber · April 25, 2024, 02:36:38 PM

The inconvenient fact that the CTY explanation ignores

is that there's a forward keel bolt, pre-tensioned and torqued to (give or take) 105 foot-lbs.

So, is CTY seriously suggesting that if the BUTT of the keel is loaded, the resulting stress at the NOSE of the keel stub elongates the bolt so that the leading edge of the stub and keel can separate?

Or perhaps CTY is implying that the J-bolt pulls out of its embedment in the lead keel.

It seems that it must be one of those two options (or both) for CTY's theory "to work."

And, the forward nut torque would change when the boat is lifted off its blocking.

I'm not saying that it's not good practice to load the keel nose vs. the butt, but as far that causing the smile,
"For every complex problem there is an answer that is clear, simple, and wrong." -H. L. Mencken