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Keel Replacement

Posted: Wed Oct 19, 2011 10:49 pm
by dilda02
Hi Folks,
I own a 1963 42’ Chris Craft Conqueror (“Sea Date”) that is in need of a new keel. The existing keel has developed a ‘roll’, which has increased in severity over the 20 years that I’ve owned the boat. In addition, the keel has a couple of soft spots, and has incurred some compression (pinching) in critical areas during haul-out in the last 2-3 years. The winch men at my club are starting to balk when hauling my boat and it has become apparent that I need to address the problem this winter.
The Sea Date is now safely out of the water for the season, and I’m preparing to lift it off of its keel-blocks by building a make-shift cradle using jack-stands and cribbing. Once this is done I’ll start the process of unbolting the keel from the boat. My current plan is to replace the existing 3-piece keel with a laminated keel made out of 1” thick sections of white oak screwed & glued together using silicone-bronze fasteners and resorcinol. I’m told that this is the technology that the shipwrights used on the rebuild of the USS Constitution. I feel like a laminated keel would be stronger than the original version and would better-resist warping. I’ve considered using other wood species and epoxy, but feel like the hardness of white oak bonded with resorcinol provides the strongest option. I’d love to hear the group’s opinions on these matters. My goal is to build the hardest/strongest keel possible. I’ve even considered adding a few inches to its height. Note that boat speed is not a big consideration here… This boat is just too big & expensive to get up on plane anymore.
I also have questions with respect to the use of CPES… Should I use it on each individual laminate? Will resorcinol bond ok with it? Or should I just use it on the completed keel once it’s glued, screwed and bolted onto the boat?
As far as construction goes, I’m thinking of laying up the keel ‘dry’ right on (or under) the boat. I live in the Boston area and our cold winters will prevent me from gluing my laminate sections as I fabricate them. I figure I can build it dry over the winter, dismantle it when the weather breaks (around March?), and then glue it all up when things warm up. I’m not quite sure what product I want to use to bed the completed keel onto the boat??? I think I want to avoid something as permanent as 5200. Again, any thoughts on this would be greatly appreciated.
Thanks in advance for any advice you can provide,
Dave

Keel Replacement

Posted: Mon Nov 14, 2011 8:57 pm
by dilda02
Hi Everyone,
Thought I would post some pics of my project. Here's a shot from the starboard side showing the worst of the compression:

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Looking forward from here:

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Here's a shot from a bit further forward:

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And now from the port side:

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And now from the stern (note the roll to port):

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I've decided to build the keel in my garage over the winter. I'll need to build in 1 big scarf joint in order to accomodate my limited work space (which had bothered me since I really want this to be strong), but given that the current keel has a couple of these already (which have held up pretty well over 50 years), I figure that it's a small consolation given the benefits of building it in a nice warm climate-controllable environment.

I also put together a short video... Here's the url:
http://www.youtube.com/watch?v=fS7w_yShaGk

Thanks,
Dave

Posted: Mon Nov 14, 2011 10:41 pm
by jfrprops
I thought resorcinol had been banned? No matter what it is old old school....and I know nothing about it.
I would make and bed that keel in 5200. Unless you are a toddler, this repair is going to out live you!lol.
Great boat, good winter project!!

John in Va.

Posted: Tue Nov 15, 2011 7:31 am
by parroteyes
No experience here, just trying to learn:

If you are going to laminate it anyway, why scarf it?

Could you make the pieces in the warm garage and then when its spring glue 'em up?

Posted: Tue Nov 15, 2011 9:10 am
by gbraker
Well you can see from the pictures why you shouldn't try to support a chris craft by the keel. It just isn't strong enough. I can't tell by the pictures, but all the ones I've looked at just hang from the keelson with large bronze bolts. It should be easy to remove in one piece if you remove or cut the bolts. Obviously the first thing you have to do is support the boat from jack stands under the bulkheads and the engine stringers. Take a look from inside and locate the bolts.

You may be able to locate them on the outside if you remove the worm shoe first.

Try to remove every other one. I have a feeling you will have to cut them and pound them out with a long punch, and then buy replacements.

That's what sawsalls are for. Maybe after it drys and the wood shrinks you will be able remove the caulk and see them.

Posted: Tue Nov 15, 2011 9:17 am
by gbraker
To tell the truth the keel wood doesn't look bad to me.

I think you just need to replace the worm shoe portion.

If there are soft spots higher up I would just scarf in replacement wood in that area. I don't think the keel needs replacement from what I can see in the pictures.

Posted: Tue Nov 15, 2011 9:29 am
by Al Benton
I'm wondering of this application may be a good one to consider an epoxy lamination process for the sections that are built in the heated garage.

When I searched for Resorcinol I didn't see a glue, only some confusing drug definitions. What is it?

Skeg

Posted: Tue Nov 15, 2011 11:58 am
by evansjw44
Looks like what you really are talking about is the skeg. The keel has all the frames fastened to it. Ths skeg adds strength and protection.

Posted: Tue Nov 15, 2011 12:59 pm
by Al Benton
Jim, isn't that considered the Outer Keel on a cruiser?

In our area we place the blocking parallel to the outer keel (skeg?) in lieu of perpendicular to it which spreads the weight over the length of the blocking.

Posted: Tue Nov 15, 2011 5:52 pm
by jfrprops
looking at those pics of the skeg...I am not at all sure I would replace anything but the bottom portion of it???/
saw off the bad bottom edge with a worndrive skillsaw and add a worm shoe or even wider piece of metal???

Pandoras box looms above the skeg.

John in Va.

Posted: Tue Nov 15, 2011 11:05 pm
by RRGadow
Im with you guys...worm shoe and splash. I dont think that at your speeds its going to be an issue.

Keel Replacement

Posted: Tue Nov 15, 2011 11:52 pm
by dilda02
Hi All,
Well, if it were only the matter of the soft spots in the keel, I'd probably just replace the worm shoe, repair the problems and call it a day. Unfortunately, the lowest portion of the keel is also rolling to port... Fairly significantly. This coupled with the soft spots has brought me to decision to replace the whole thing. And I'm not sure the compression damage and splitting of wood in the keel can really be properly repaired. I think the video shows the problems better.
Dave

Keel Replacement

Posted: Wed Nov 16, 2011 12:11 am
by dilda02
Hi John
In response to your posts... Yeah, you can still buy resorcinol, at this location:

http%3a%2f%2fchemical-supermarket.com%2fG-1131-Resorcinol-Structural-Adhesive-p90.html

I'm planning to use resorcinol because it bonds so well with white oak (whereas epoxy does not). I've used it before (building a teak swim platform) and it works great.

I need to build in the scarf joint because I don't have the 31 feet of space needed for the full keel in my garage. I'll build it in 2 pieces and then bolt/glue it together onsite before I bolt it onto the boat. Well, at least that's my current plan... This has been an evolving process (and still subject to change).

Thanks,
Dave

Posted: Wed Nov 16, 2011 9:09 am
by jfrprops
Resorcinol was the primary glue back in the day, and was applied wet to the mahogany hull strips, dried on racks, and then when the hull was placed in an autoclave under heat and pressure that glue became a liquid again and penetrated the wood, and that is how you made the early , formed in place on a mould, plywood hulls like my Whirlwinds, and wolverines and etc...neat process. I was NOT suggesting using any epoxy...just 5200....and I am "stickin" to that opinion.
Good luck on this project, a big one, but clearly you have a good plan!
John in Va.

Posted: Wed Nov 16, 2011 11:52 am
by mbigpops
Dave,

I am just going to throw this out there. I am not far from you to the south in mass and I was able to find a sawmill in Connecticut with white oak and experience cutting keels for large boats. I was told that my runabout keel was cut from scraps for a larger boat.

If interested I can get you their phone number (don't expect much more as this is a real backwoods operation).

Mark

Keel Replacement

Posted: Thu Nov 17, 2011 12:21 am
by dilda02
Mark,
Sure, you bet.. I'm very interested in finding a source for seasoned white oak. I still think I'd like to build a laminated version (for strength reasons), but I'll listen to arguments for doing it the traditional way. Please send me their contact info if you would. I live in the southeastern portion of Mass (town of Norfolk), so Conn. would not be too far.
Thanks very much,
Dave

Posted: Thu Nov 17, 2011 9:39 am
by mbigpops
Dave,

Pike's Sawmill
311 Providence Turnpike
Hampton CT 06247
860 455 9968

Ask for Clarence.

I am in Attleboro.

Mark

Posted: Thu Nov 17, 2011 9:53 am
by jfrprops
Important to this topic. See page 127 of Tony Mollica and Chris Smith's book "Building Chris Craft".
"....the oak skeg was purposely made from green lumber.....never stored exposed to the sun...intention was to use quickly before it had a change to age and lose moisture content. When the skeg was installed..(they)..always left a space between the skeg and the bottom. this intentional loose fit was deemed necessary because if the skeg was fitted tight to the bottom, as soon as it became continously wet, it expanded and snapped off the (keel) bolts...bolts were left loose to accommodate the swelling that surely followed. By using green oak lumber the company minimized the amount of expansion". so the fit then tightened. think about this? Green oak was going to shrink, fast, in the air, but swell a little bit underwater...neat plan...consider? John in Va.

Keel Replacement

Posted: Thu Nov 17, 2011 10:59 pm
by dilda02
Mark,
Thanks very much for the info... I'll give them a call.

John,
Great point... I'd heard some folks talk about this, but your post verifies this concern. This creates a bit of a problem for me, as I need the wood to be at 12-15% moisture content (as I'm told) in order to properly glue each laminate together. "Going green" will not be an option for me if I keep to my plan of building a laminated keel. And just how lose do I bolt it up? It scares me to think that I'm not going to bolt this hard to the boat. I wonder if I could pre-soak it (once built) and then bolt it on??? Maybe I could go a bit bigger with the bronze rods? I think I recall someone telling me they were 5/8". So many questions...

Thanks to all for your help,
Dave

Posted: Fri Nov 18, 2011 7:53 am
by mfine
If you are going to laminate it, wouldn't you want to use something like West that will seal the wood and prevent swelling? Seems to me letting the different layers swell and shrink, especially with something flexible like 5200, is going to give you problems. I would want a strong stable keel and let the planks do the swelling.

Posted: Fri Nov 18, 2011 10:58 am
by maritimeclassics
If it was me doing the job I would build it just the way they did. You are not going to add any strength to the skeg if you laminate, it would just be an extra step that is not necessary. You also may find that the worm shoe is a different type of wood but may be white oak. I would use green white oak and use Dolphinite in the joints from one piece to the other and then bed the whole skeg to the hull with Dolphinite using bronze bolts. Also you need to keep these little critters (Teredo’s) from going from the worm shoe to the skeg. I have heard of using Irish felt--aka "fancy tar paper" or you can bed with Dolpinite. Do not tighten the bolt to the skeg really hard but you can make them snug so when you pick the boat up there is no movement. I would not go with laminating green wood, I my opinion nothing like 5200 or epoxy is going to give you the bond you need for strength. I would be worried that it would fail down the road.
Here is what is said about Dolphinite: 2005 Series Bedding Compounds are flexible, semi-paste type, slow oxidizing waterproof compounds for bedding in joints in keel, keelson, stem, sternpost, transom, battens and other hull members. Also for bedding in deck fittings, mouldings and trim around deck houses. May be used on wood, fiberglass, and metal or wherever a waterproof seal is required. Apply by hand or pressure gun or putty knife. Thinning is not normally required. May be painted over after the compound has firmly skinned over.

Posted: Fri Nov 18, 2011 11:20 am
by jfrprops
very good advice in the just previous post...

John in Va.

Keel Replacement

Posted: Sun Nov 20, 2011 12:34 am
by dilda02
Mike/John,
I'm not adverse to changing my plans... and if a laminated keel would not provide more strength and/or warp resistance, then I have no interest in going that route (I have no desire to make this project any more difficult than it need be). But this is contrary to the advice I've received from other sources. My plan was to screw & glue the white oak laminates with silicon-bronze fasteners & resorcinol.
Guess I need to do some more research. I certainly like the idea of remaking the keel (skeg) it as was originally built. The issues you outlined earlier are leading me in that direction. Again, my goal is to build this as strong as possible.
Thanks,
Dave

Posted: Mon Nov 21, 2011 10:15 am
by maritimeclassics
I would think that the weakest point would be where the skeg meet the keel along the bottom of the boat. I would bet when you take the large trough bolt out in the area of where it is warped the bolts are bent. Also there is no way that resorcinol is stronger than West system epoxy, the problem is the green wood, that is why I would keep them one piece and scarf them like the factory did. In my opinion the reason that you have warping was from the way it is laid-up for winter each year. These boats were not designed to sit for periods of time on there skegs and would have never happen if it stayed in the water. So I would stay with my original plan and if you wanted extra strength I think the only way to do it is to add something on the inner keel where the bolts go through. Something like a keel cap of oak or stainless steel, but then you would need to tighten the bolt good and tight which may not be the best thing.

keel replacement

Posted: Mon Nov 21, 2011 3:13 pm
by dilda02
Mike,
Thanks for your note... I suspect you're correct in that I'll find that the keel bolts have bent when I remove the skeg. And I'm sure you're right in that this has been caused by the way the boat's been layed-up during the off-season. I'll need to make sure that situation is corrected going forward. I wasn't suggesting that resorcinol is stronger than epoxy... My reason for using resorcinol was simply because I've been advised that it bonds better with white oak than epoxy does.
But I've been rethinking my plans in light of your posts, and called the sawmill that Mark made mention of in his post. These folks have evidently made a bit of a specialty out of building replacement keels, and have suggested that I eliminate the scarf joints & simply build it as 1 big piece. Is there any rationale for keeping those scarf joints (possibly for expansion)? There are 2 of them on my skeg.
Thanks again for your help,
Dave

Posted: Mon Nov 21, 2011 7:03 pm
by maritimeclassics
I would think the only reason was the cost and handling of a large one piece keel. But with that said I always try to do things the way they did, in this case not for originality but I always think they new a lot more then I do. But keep it simple and fun and I am sure it will be fine you are headed in the right direction.

Keel Replacement

Posted: Tue Dec 20, 2011 11:08 pm
by dilda02
Hi Folks,
Figured a post a few pics of my recent progress...

I cut the nuts off the keel bolts with a grinder and punched the bolts out from the inside.
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I had to cut a few new holes in my flooring to gain access to all the keel bolts:
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I reefed-out the seams and the keel came down without much effort. Keelson looks pretty good after almost 50 years:
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The last few sections of keel dropped down on the jackstand chains:
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And just when I thought everything was going well I came to realize that I need to replace a couple of the garboard planks... Ugh! My job just become a good bit bigger.
Dave

Posted: Wed Dec 21, 2011 7:15 am
by parroteyes
Great post!
Like the pictures.

While the job gets bigger, the result gets better. There really is a pony in all this s#*t! Keep digging.

Posted: Wed Dec 21, 2011 8:35 am
by maritimeclassics
It looks like it's coming along and you have some good pattern pieces to work with. I think I would put a couple of coats of CEPS on the underside of the keel, keep us posted. Good Job!

Posted: Wed Dec 21, 2011 11:35 am
by jfrprops
This is really making progress! Keep at it, so far you are ahead of the "pandora's box" game....only need to do reasonably expected stuff.

Keep us "posted" and the pics are great.

John in Va.