so I bought this boat..........

thanks for the lead, its a MK2 unfortunately but they are very close, and that is the root of the frustration, there is info available for the MK2 but not the MK1, and everything changed, ballast, keel, interior. it looks the same from waterline up to mast but everything else is different. im starting to wonder if they were embarrassed by this boat and just turned it out and quietly moved on to the next model! lol

 

Always be aware not to over capitalise on an old boat..yes you want it safe and looking good so paint is the way to go ..can you not just drop the mast to the keel/cross baulkhead if you need to re rig it anyway ?

 

well, the mast and rigging are in great shape, all cables are new and swages are correct and secure, and I have a brand new main and jib so I was going to try to keep the mast length standard, I do have to re-bed and attach all rigging brackets on the hull, thats what I meant by re rigging. the mast on this boat mounts to the top of the cabin by means of a couple of pieces of aluminum plate welded together which under closer inspection revealed a crack starting to form in one of the welds, I had an aluminum slug milled into a sleeve with the same mounting holes as the old one and I am planning on using that, but it got me thinking that I could benefit from extending the mount on the inside (maybe a pipe or octagonal structure that bolts to the mast mount hdwr from the bottom all the way to the keel. I have also made a 2 ft square "washer" of sorts that will bolt under the mast plate inside the cabin to help distribute the load over the entire cabin roof. Like I said, its a weekender and maybe a short run over the open ocean but mostly lakes and the gulf, and I like a stiff wind but am not into having the boat almost horizontal in the search of speed. I am also looking into upgrading the keel ballast to something a little more current, I was thinking about a torpedo design like the ones offered by marskeel.com, but again, if I cant make it in the garage, then its too expensive! total ballast on my boat is 1100 lbs, I was thinking about an I Beam construction with an old oxygen bottle for the torpedo, make a sheetmetal surround on the I beam for a nice smooth, low drag coefficient, weld together with a 1 in thick mount plate for the hull mount, and fill with lead shot to reach desired weight and throw the whole thing in the oven to melt the lead and viola! new keel ballast. Think it will work? I have also heard that if you go that route you can go with a shorter keel length which would be great for me so I can launch from a wider variety of boat ramps (not all lakes around campbell have a crane available).

 

I think your idea is very clever and resourceful. It will do a good job of lowering the Center of Gravity (CG) per given keel depth.

The thing you have to think about is if you have enough lateral area. If you make the keel shallower its area is going to have to increase to compensate for:
1.) Less keel area, and
2.) less efficiency due to a lower aspect ratio.
And even then you will lose some pointing ability. It's just a matter of how much.

Then you have consider balance. The center of the keel area is not necessarily the Center of Lateral Resistance (CLR). Depending on the design of the original keel, the CLA could be anywhere from 33% to 38% aft of the leading edge of the average chord (average length of the keel). If you make the keel longer to compensate for loss of area and loss of efficiency (due to making it shallower), you risk having either the CG of the keel to far aft or the CLR too far forward. Many long keels have box sections and blunt ends for this reason.

My vote is for keeping the original keel.

For a truly trailer able boat, I would recommend converting it to a center boarder with a heavy, metal plate for the center board and some internal ballast. The board can be quite long and narrow, so, when extended for normal sailing, it will lower the CG of the boat considerably. But this would be a major project.

With my Siren 17, I discovered that a center boarder can make some windward progress even with the board all the way up, even without a skeg.

If you just shorten the keel and keep the chord length the same, you may be giving up considerable windward capability, but will still be able to make it to windward. Just more tacks.

Best of luck to you.
And keep safe.

 

thanks for the input! The original keel might be the better option, I talked to the folks at marskeel.com, they told me i was looking at 6 or 7 thousand dollars for a replacement torpedo design that would keep the factory CG and improve the total overall performance of my boat, but I dont have that kind of cash floating around... the original keel is suspect....there is a lot paint and flaking of metal going on there, some large splits in the front of the keel as well as pieces flaking on the sides, i took a ball peen hammer to it when i got it to see how far the rot had gotten, largest piece to flake off was 1/4 inch thick, so it gives the indication of being surface damage only, but its still 41 years old, and god knows how well it was kept, looks like at one time it was coated with epoxy, then gel coat after that, then painted as well, but not all at the same time, honestly i am worried about the darn thing snapping off because of some invisible crack. If I do keep it whats the best way to protect it? I was thinking of sand blasting, rust stopper paint after that, filling with metal set and filler to make it even and smooth and then wrapping the whole thing with fiberglass, someone else suggested that I coat it with the 3M latex paint that you use for tool handles. How much of the original keel can you loose before it becomes ineffective? and as far as making one, if I kept the same length, width, and heigth of the new one close to the old, just redesigned to a more advanced design would that keep all the charateristics the same? the mass that I loose in making the wing thinner and smaller, I could compensate for in the bulb, perhaps making it a little fatter like an oval tube, but overall the same length and located in the same position relative to the old one.

 

I think it would be best to have a professional look at it. Some of these keels are held on with flanges and some are through bolted. If yours is through bolted, the condition of the bolts is your main concern. If it is held on with a welded flange, (which is then bolted to the hull) all this rust is quite scary. Especially if its on the flange or flange/keel joint You may end up only having to replace the keel bolts. The rest of the keel can then be sand blasted to the bare metal, spray galvanized, epoxy coated, faired, then painted. It has probably lost some mass, but not enough to really worry about.

 

Coronado 23 vs. Coronado 23 MKII

The Coronado 23 you have is an entirely different design from the MKII version. The one you have is nearly the same as a Columbia 22 (by William Crealock) but with a different coachroof.
http://sailboatdata.com/viewrecord.asp?class_id=263


The MKII, on the other hand is nearly the same as the Columbia 23T (by Alan Payne). The 'T' mostly likely meant something like trailerable.
I can't say that I have first had experience with either one, but I would think that the model you have is a far better performer under sail than the MKII version, which was intended to be better on the trailer at the expense of the sailor.
Best of luck with it.