Blocking for under Wing Keel on 1987 C34

[Mike McDonald]

Hi all,
My boat is coming out of the water next Saturday, and I need to buy some 6"x6" Pressure treated blocking for under the keel.  Does anyone know the length of the wing keel.  I thought I would put a couple of 6x6's fore and aft and then a few pieces on top of them at 90 degrees for the keel to rest on.  Not sure how long the pieces should be.  I should have measured before it went in the water in the spring.  I'll be using six side stands (3 per side) and a bow "V" stand.  Thanks for any input you may have.
Mike.....

[Ron Hill]

Mike : There have been a number of Mainsheet articles written on blocking a wing keel. 

You need the weight of the boat on the nose of the wing NOT on the aft of the wing!!  I seldome have any blocking under the aft portion of the wing. 
If you don't keep the 75% of the boat weight on the nose of the wing, it is guaranted to have a Catalina Smile!!   

[Steve W10]

Hey Mike, my '88 Wing Keel is 71" measured down the centre.

I've been struggling with my cradle since the day I got it; every year it fits a little better.  The way we haul-out at our Club (putting the boat on the cradle and then moving them together) makes it difficult for me to get that 75 / 25 distribution but I'm working toward it.

The other thing I'm working toward is getting the right bow-up attitude for decent cockpit drainage.  Even though the stupid thing doesn't drain in the summer, might as well try to get it to drain in the winter.

[Mike McDonald]

Thanks Ron and Steve.  It sounds like I should keep the blocking biased to the forward part of the keel, maybe the forward 1/3rd?  As always, I appreciate everyone's input.  This is my year of "firsts" for all of this.
Mike.....

[Steve W10]

Don't know it this will help but here's what I found to be where the centre of mass exerts its force on the keel of my boat.  This is with no weight on the pads.  You can see under the keel forward and aft of this point.

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Ron, don't cringe too much, this was the second year on my cradle, last year I moved it forward I think 18" which didn't help as much as I'd have thought.  This year I'm revamping my wedge to incorporate the curvature of the keel (to avoid bending the longitudinal beam of the cradle thereby reducing the twisting of the cross-members) and trying to get the weight on the front.

[Ron Hill]

Mike : Steve is in a shipping craddle.  Follow my advice if you use jackstands!!  

Block the first 1/3 but make sure the travel lift operater know that you want the majority of the weight on the NOSE of the wing.

The engine and a full fuel tank are all aft the CG.  The lead wing just sits there and the worst thing that will happen is that the heavier stern will rotate down causing the "Catalina Smile".  75% weight on the wing and 25% of the weight on the pads!!   A few thoughts

[Jim Hardesty]

All good information and advice.  Steve has the center of mass (balance point) marked right.  I think that the important part is the pressure on the pads, jack stands or cradle.  The keel is big and solid, it's not flexing.  The only pressure or lifting at the keel joint will be put on by the pads, especially at the bow V-stand.  One of the main problems up north where the ground freezing can change the pressure on the pads a lot.  Not so much of a problem when storing on a concrete pad, some on asphalt, more so on ground.  Jack stands need to be checked and adjusted, both at freeze and at thawing, often.  What I do... I use very little pressure on the V-stand, then after the boat is winterized and cover is on, I back it off 6", way off the hull.  I keep the jack stand pair forward of the keel just snug.  That way I'm sure not to get lift at the front of the keel joint.  When I'm working at the bow of the boat I'll bring up the V-stand to touching for the day.
If you winter at a boat yard they should be checking, ask the manager.  If you are like me and at a yacht club where you are responsible for your boat, visit during the winter.  Or get a buddy to do it.
Jim

[Mike McDonald]

Thanks everyone for all of the great information.  I really appreciate it.  This really helps a lot!!
Mike......

[andre]

What's a Catalina smile? and i don't find a tech note about the blocking a wing keel. I have a berr with a 6 adjustable pads but i don't understand why you said 75% of the weight on the front of the keel. Excuse my English i'am learning

[Roger Blake]

Andre--Here is the Catalina smile (in my case, a half smile), due to improper blocking from a marina. The pic is after I found the crack and ground down with a Dremel tool to fiberglass the repair.

[Stu Jackson]

Roger's is an "ODD" "smile."  Usually the "smile" is horizontal, at the line between at the top of the keel.

[Jim Hardesty]

For general information we should say that what we are calling a "Catalina Smile" is not limited to Catalina's.  My observations are that Catalina's have a better than most hull to keel joint and with proper boatyard care the joint won't be a problem.
JIm

[andre]

Thank you for the smile, where can i find some information about the best way for blocking with photo.

[Mike McDonald]

I'm a little confused by Steve's photo showing the center of force.  It appears to be more toward the rear of the keel.  Is that because the stern is lower than it should be?  It sounds like the blocking should be aligned with the forward third of the keel, not the rear.  Am I missing something?  If I am blocking from the ground, should I place the blocking only under the forward third of the keel, or raise the stern enough so that there is space below the rear portion of the keel?  I plan on using 6 stands on the sides and a V-stand on the bow. I would appreciate some further clarification.  Some pictures would help.  Thanks.
Mike.....

[Ralph Masters]

Roger's "Smile" does not look like a seperation in the ballast to hull joint, it looks more like a very serious crack in the keel of the boat, like it's about to break the boat in half.  I'd be very concerned about a crack of that nature.
Has that boat struck bottom hard???
Ralph

Ciao Bella