O'Day 20 Rebuild and Refit

Questions about boat repairs with our resins and fiberglass: hull patches, transoms and stringers, foam, rot etc.
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gk108
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O'Day 20 Rebuild and Refit

Post by gk108 »

I've been slowly making progress on my latest project, a 1973 O'Day 20 sailboat. First, I had to work on a place to work on the boat. That took most of the winter, then a few weeks ago I took the boat off the trailer and set her on the hard.

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I blocked under the stern and lifted with a hoist and sling under the bow.

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There's a total of 5 screw jacks to level the hull, plus timber framing underneath to really stabilize it. Here it is just at the beginning of the leveling process. She shows a flat bottom amidships.

This week, I've been doing demolition in the v-berth area, working my way aft. Most of the structural problems on the boat that I'm aware of are located from the mast area forward. The plywood tops to all the berths have rotted due to a variety of leaks. The cabin sole has rot problems, not surprising since the bilge side is raw plywood. The sole under the mast compression post is indented, telling me that the sole is shot in that area.

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Here's what the v-berth looked like after the top was removed. The cavity was stuffed with foam batts, about 10% were waterlogged. Notice the complete lack of framing. It's just a big open tub up there.

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I crawled up in the tub and took this picture looking aft at the bulkhead and port side of the hull liner, where the porta-potti is located. This large unsupported area of flat bottom bounces like a trampoline when the boat pounds in the waves, so I plan to add some plywood framing. I'll probably cut the liner out in pieces and replace the part where the porta-potti sits with a full transverse frame at the front and another forward of that with longitudinals worked in. A freshwater tank and electric pump will go up there, too.

The bulkhead is not bonded to the hull in any place. It slides into slots molded in the liner and fastens with hardware. The compression post also fastens to the bulkhead. Even without the rig, I have to jack the cabin top a little bit to get the post out. I see trouble down the road, since I'll be removing all available reference points for the total height of what's under the compression post. Once I take it out and remove the jack, the cabin top relaxes down, so that end moves. The bottom end has already moved due to rot, but it gets removed, too. All that leaves me with for absolute measurement is the compression post. In other words, I know how long the middle is, but I don't know how long the ends are. :doh:

I started a blog to keep a record of this whole escapade:
http://www.gk108.ersweb.com/vlogs/index.php?rn=4
It's still under development. :)
CC, D15, V10

TomW
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Re: O'Day 20 Rebuild and Refit

Post by TomW »

You have your work cut out for you guy! We always use to laugh at the O'Days when I was sailing/racing on Cal 20's but did'nt think they were constructed like that. 8O You will definately have a better boat with what you plan to do. :D And don't get me wrong they were good sailing boats also. :wink:

Tom

PS you coming down to Boca with your beans and rice? Will sure miss you if you don't.
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PAR
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Re: O'Day 20 Rebuild and Refit

Post by PAR »

Interesting, I've just started on a 74 ODay of the same flavor (okay it's a 22). I'll be doing considerably different then what you might be envisioning, but I've just removed the deck cap and liner. A couple layers of biax on the bottom riding well up the topsides will stiffen the fore foot up considerably, without the weight of bulkheads. The boat's fairly heavy as it is. Also check out the transom,core, which will probably be rotted too.

On my version of a rebuilt ODay, the stem will be filled out to a spoon shape, the transom will be cut off, projected aft and curved, with a mahogany veneer skin, the sheer lowered, the stub keel extended, an under slung, kickup rudder fabricated and of course the rig. Hay, you get one of your long time accounts, to talk you into to this and see if you say no, particularly in this economy. I've pretty much talked him out of wheel steering, but he still wants one. Note the fisherman on a roller furling drum.
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Re: O'Day 20 Rebuild and Refit

Post by gk108 »

Tom, it may not be the fastest boat out there, but I like the way it sails. With 10 mph winds, I can trim the sails, snub the tiller and steer by moving fore and aft in the cockpit.
It doesn't look like I'll make it to Boca. :cry:

PAR, that's a lot more of a project than I'd try, but I'm only engaged in a hobby. I like the general layout that O'Day used for the 20 and I'm going to try and maintain that layout with a few improvements. The galley area is going to be made more convenient by sizing it for a 1 burner stove and moving the sink towards the center to get it out from under the side deck. I'm not really worried about some extra weight in the bow because I almost always move ballast up to that area to trim for easier sailing. If I wasn't planning on installing a water tank up there, I'd probably go with less framing, but I'd still need support for the middle of the berth top. I am planning on 1 layer of biax up there and there's a spot that will need a patch built up from the inside.

The actual transom has a 2'x2' cored area on the starboard side for motor mounting, but the port side has no core. The aft end of the cockpit has some strong core in it and the backstay is anchored to that instead of the transom proper. I crawled back in there a couple of years ago and found no signs of rot or leaks.
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Re: O'Day 20 Rebuild and Refit

Post by TomW »

I like the way it sails. With 10 mph winds, I can trim the sails, snub the tiller and steer by moving fore and aft in the cockpit.


This is why I said that they were good sailing boats, everyone who had one liked them. 8) Sorry you won't make Boca! :(

Tom
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Re: O'Day 20 Rebuild and Refit

Post by gk108 »

They do some funky stuff with the hull shape just behind the stub keel. It's kind of subtle, and at first I thought I was looking at an out of shape hull. At the aft end of the stub keel, the bottom is a very slight inverted vee, as if the middle of the hull begins its upward sweep before the chines do. About 18" behind the stub keel, it all blends into an even curve and the vestige of a keel reappears to make a wineglass-like transom.

I guess the only real handling problem that I could complain about would be solved by getting a Seagull motor for its LH turning prop. With the motor mount on the starboard side and a RH turning prop, I have gearbox control for two directions: forward and left. :lol: But, instead of a Seagull, I'm going to take the 9.9 off the D15 and hang it on this boat. I've learned to use the prop-walking to my advantage, like a bow thruster, only different. :D
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Re: O'Day 20 Rebuild and Refit

Post by gk108 »

Cabin windows removed, gone for good, I hope.
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Here's the way it's put together, a liner and a deck, the old window frame clamped them together. Bulkheads span the window opening. The original windows are history. They will be replaced with some fixed portlights after the big holes are filled with some kind of solid panel.

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Here's the view from the inside. The portlight hole forward of the bulkhead will be half on the patch and half on the original, just to make sure I have fun doing that part. Next step is to scab some gap fillers on the old bulkhead, so that I can use it as a template for the new one. Then it gets removed and the demolition process grinds on. 8)
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Re: O'Day 20 Rebuild and Refit

Post by gk108 »

Getting closer to the bottom of things.
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The cabin sole, showing how much the compression post has pushed down without rig tension.

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The top of the post and backing plate for tabernacle hinge. I could go on about this series of poor choices for a while. I'll just say that keeping a mast in column should involve compression support that is also in column.

I want to replace the whole arrangement with a SS or aluminum post with flanges welded to the ends. I have no idea what the righting moment of this boat is, so I can't do any calculations for the compression forces. I need some kind of an idea so I can make sure that I use strong enough tubing. Anyone have any tips :?:
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Re: O'Day 20 Rebuild and Refit

Post by TomW »

Gary I never saw an OD20 knocked down so it is probably fairly high, . Maybe PAR has it in his database. Also check the Web they were a pretty popular class and there maybe an owners group on it if you haven't already done so, ah nix that you probably already have. :D :lol:

Tom
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Re: O'Day 20 Rebuild and Refit

Post by gk108 »

I spoke to the good folks at Dwyer Mast, thought about it for a while and decided that I can do some reverse engineering based on the original teak compression post. The next step is to see what tubing is available locally, because what I've come up with so far is that it won't take much of a SS tube to match the strength of the teak. The short span from sole to cabin top with both ends anchored gives quite an advantage, compared to the long spans of the spar above deck with only one end anchored. I could improve upon whatever I put in by adding a brace halfway up, about galley counter top height. If I can find the right tubing, that won't be necessary.

We made an executive decision today. The old hatch on the cabin top is going to be replaced with a Bomar N1060-10A hatch. Making that fit the curved cabin top will be a challenge. :lol:
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