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New to the site and glad I found it. I just picked up a 58 Cortland built 16' Sea Coaster model475. She was bought new at a still operating marina on Cayuga lake and has been on the lake her whole life. I am only the third owner and have the original sales brochure for it and the 35 Johnson outboard which is still with the boat. The boat is cosmetically beautiful and sound from the outside other than some sloppy caulking near the keel cap. Internally it's another story. The keel and center of the ribs are fairly rotted, garboard strakes seem sound. I am comfortable with the woodworking skills required to do the work but I am having trouble disassembling the boat.
first off, I apologize for not knowing the technical terms of all of the parts. I will describe what I see and let you educate me. I flipped and stripped the boat and removed any caulk and packing around the keel cap. The cap was through bolted with 6 or 8 carriage bolts. Internally I have the stringers which are fine, running down the centerline, bow to stern is roughly a 1 x 4 lying on its face. I've heard this is called a keel batten but don't know if that's correct. On top of this batten in the aft section is a "T" shaped structure. The head of the T connects to the stringers, the leg runs aft and connects to the transom. This batten and T received the through bolts from the keel cap and were capped with a square nut. I have removed all visible hardware and none or the structures will come loose. The keel cap, after pulling up some on it seems to have a bolt coming up into in from internally, yet the "T" has a fastener running down into it from externally. How is this possible? I am anxious to start the repairs but I'm stumped on the disassembly? The wife is starting to give me the skunk eye. Any info will be greatly appreciated.

Addreas is the resident expert on Thompson boats. I restored a 1960 Cortland boat about six years ago. I think if you sand down or strip the paint off the outside keel you will find 3" to 4" long screws every foot or so that are recessed into the outside keel. Hope this helps

Everything was nailed together first before being screwed or bolted. So there most likely are nails still holding stuff together after you removed screws and bolts.

Andreas

Greetings.

I have a cortland boat as well and have disassembled the outter keel etc. There are indeed as noted above a number of long screws in addition to the carriage bolts holding the outter keel on. Take a look at my thread (bottom rebuild ( previously.... for pictures and verbose commentary on my part.

Also, the keel cap is payed with an adhesive sealant so be gental and patient removing it.

Feel free to write at the address on my profile.

I looked closer and the keel cap is definitely screwed from the inside out but if it went together there has to be a way to take it apart. Thanks for the comments.

Mine came apart like this; Apologies if it assumes too much (or little) about what you know already. This also assumes our boats are constructed the same or similar.

- Stripe the paint off the bottom of keep cap (the piece on the outside of the hull on the bottom) down to the wood. Then sand it. This exposes the bungs for both the carriage bolts and screws, and locates any nails.
- Remove the bungs to expose the screw heads and bolts heads (in my boat, the 'bungs' were an array of different material from caulk to filler to who knows-what-that-stuff is). Clean these holes out really well to facilitate removing the screws and carriage bolts later.
- Remove the screws from the outside of the hull. Keep track of the order from front to back so that you know where they go back (they are different sizes and lengths). Note, the screws are likely fearson head screws, NOT philips head (similar looking but very different). A slightly undersized Phillips head will work on fearsons to remove them, but not for installation.
- The carriage bolts are installed from the outside of the boat after the keel cap was installed and so will be driven out from the inside. These bolts are silicone bronze or some such soft metal, so we cant just drive the bolts out with a hammer or some such as doing so will flatten the end and damage the threads.

The nuts are on top of the main keel in the center or the boat. So, from inside the boat, back the bolts off until the surface of the bolts is juuust proud of the surface of the threaded end of the bolt. Take a small block of wood and set it flat on top of the bolt. Now strike the block with a hammer to break the carriage bolt free. Keep the block flat. May take a few strikes.

Once the bolt breaks free (you'll know cause it will move down), we can remove the nut the rest of the way and drive the bolt the rest of the way out. We need something straight and slightly less in diameter than the carriage bolt. I used a long, standard steel carriage bolt of a lesser diameter. Place it on top of the bolt to be driven out (threaded end to threaded end), and keeping it square, drive the bolt the rest of the way out by striking the steel bolt with a hammer.
Like the screws, keep track of the order they come out front to back so that you know which one goes back where for reassembly.

As mentioned above, make sure the heads of the carriage bolts are fully exposed and the counter sink holes are completely cleaned out so that the bolt is free to move out. If not, you could damage the keel cap or bolt when driving it out.

- Now to remove the keel cap. On my boat there was lots of caulk payed along the edges of the length of the keel cap. Remove it all being careful not to gouge the wood. Get it all to make the rest of the process easier. I used a variety of tools. Paint scrapers, putty knives, chisels (be careful with chisels!).

The keel cap was applied with an adhesive sealant spread across the bottom of the boat and the bottom of the cap (that is, not just along the edges of the cap), so patience is needed to separate the cap from the bottom, else you may crack or split the keel cap. Prying at it will rip the top plys off the plywood, making for much more work later. Even if you plan to replace the cap, it's easier to pattern a new one if the old one is intact.

Starting at the stern end, work a broad putty knife under the cap. Tap with a hammer, push by hand, work back and forth, etc, and work the knife under the cap to separate it from the bottom. Resist the temptation to pry at the cap just yet. As you work your way up the cap breaking that seal, insert shims under the cap to hold it off the bottom and apply a gentle prying force. This makes it easier to get the putty knife in under the cap where you are working. As you get farther along, shims become a hassle. I switched to a block of wood about an inch thick and moved it along with me.

If you get to a spot where that cap just doesn't want to separate from the bottom, look for a missed screw or a nail. I encountered a few nails that I assume were used to position and hold the keel cap in place for the drilling of holes and placement of screws, etc. One of these nails I had to cut with hacksaw blade.

On my boat the keel cap and stem cap were lapped over where they meet, and then a screw driven to hold that joint. Be careful here, and look for a placement nail. As you work your way forward all this gets easier. Don't let that get you in a hurry.

TIP OF THE DAY
When sanding, wear a GOOD dust mask (not the silly paper cup version). These boats were built when lead paint was the norm. You don't want to be inhaling that stuff.

Now even more fun. You'll want to remove alllll of that material that was payed onto the keel cap and bottom of both the bottom and the cap. It's tough stuff, hard but not brittle, and heats up and gets gooey if you are aggressive with say a belt sander (which is what I used). Keep the sander moving around so that the material stays cool and hard and doesn't clog your paper (or belt). Even so, the belt loads up with that stuff. To clean it off, hold a wire brush gently against the running belt. Cleans it right up. Check the surfaces often as you are sanding so you are sure not to sand past that first ply of wood.

Excellant, Peter. Wish i had that info before removing mine! I used old keel as pattern, even though it broke where the hole was. The Only thing i would add is that mine only had 2 carriage bolts at the bow where it joined the bow stem (?) part. Those were the only 2 holes that had to be exact. All other pilot holes were 1/2in off from original to reach new wood in keelson. Also, used new stainless screws that would not twist off.