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I am tackling a rib replacement job next and want to make sure I am on the right track.
The pictures included show the ribs closest to the transom. My question is do I need to remove the cheek board to scarf in a couple of ribs. Secondly. If I do remove the cheek should I run a bead of 5200 along the keelson to help seal the seam between the bottom and the keelson. Just a thought….

ribs are in great condition on the sides.

starboard side ribs show signs of rot due to plugged water pass through in the keelson.

This rib cracked the hard outer shell to expose the soft inner rot.

Remove the bad wood and create a scarf joint into the old wood. Use all heartwood white oak. Do not use any sapwood and do not use red oak. If repalcing portions of adjacent ribs, make sure you stagger the joints one rib to the next - you don't want them all in the same area.

I am not sure what you are calling the "cheek."

Do NOT caulk inside the boat at the keelson. All that will do is block the limber holes between the ribs and keelson and stop the flow of water. I am working on the second boat in as many years where previous owners did just this and it caused all sorts of unneccesary problems. You may want to remove the outer keel and recaulk under it.

Do these structural repairs/restoration FIRST, before buying varnish and sandpaper to refinish the varnisned work.

Andreas

I plan on scarfing in the ribs first before restoring the finish.
I was told that the two boards that sandwich the keelson were called cheek boards. Do you think that I need to remove this board in order to inspect for rot? I have felt around with my fingernail and found a small amount of movement when pressing on the keelson. 1/8inch or so when wet. I see no other visual rot in the keelson or this side board.

Will I be able to see the condition of the bottom plywood after I remove the outer keel? I want to make sure this boat is safe for the river and lake Erie.
Note: Last fall, I did make a repair on the bottom from the outside, in this same area, using Smiths "fill-it epoxy filler. This was to fill in a section of plywood where the outer layer of plywood delaminated. After filling with Fill-it Epoxy", It is now hard and strong. The picture above shows a section where the 1st layer had delaminated on the inside. This is very much the same as I had seen on the outside. How do I test to see if the bottom plywood is strong? I weigh 200lbs. and can stand on any part of the bottom without worry. I am assuming that the ribs take most of the stress and flex caused by waves. Please let me know how to test the bottom for strength.

When you remove the keel cap you will be able to survey the condition of plywood at keel and also the condition of the Keelson itself. A sharp icepick will give you an idea if wood is hard and firm or soft and mushy.
You may want to inspect bolts that clamp keelson boards together all the bolts in mine were broken. You will probably run across this in the vertical bolts that hold on keel cap also.

If I use an ice pick, I press lightly I am assuming. Probing pressure right?
The bottom is 3/8 plywood right? I would probably be able to push a pick through with enough pressure - even on new wood. I need to be sure this bottom is strong but I do not want to damage old but good wood.

Thanks for your expertise.

Ron

By keel cap you mean the keel that screws into the keelson sandwiching the bottom plywood, right? Is the keel difficult to remove? Last fall I patched the bottom and painted the hull with hard copper racing. It's the only finished part of the boat or so I thought.

I thought that all I had to do is replace the ribs by epoxying and bolting in from the bottom. Do you feel that I should go through the process of removing the keel? What do I use for bedding when reattaching the keel? My guess is that it will not be that bad of a job and when I am done I will be able to trust the hull and hopefully reduce the leaks.

The bad ribs are the last 3-4 ribs. That part of the bottom does not have a keel just a metal strip. Should I just remove this metal strip and probe around? Again, what should I use as bedding?

Here's what I did plus a few other boat pictures.

www.aerialimaging.net/john

Ok, terminology class 101!

Keelson: sometimes called "inner keel" is on the inside of the boat and on Thompson et.al. boats is made up of three vertical boards screwed together to form a single "triple keelson"

Sister Keelson: these are the two longitundinal "stringers" inside the hull in the bilge that parallel the keelson. They are about 18 to 24 inches on either side of the keelson.

Keel: this is on the outside of the boat, it is a completely separate piece from the keelson. It is screwed into the plywood garboard planking and into the keelson.

Rong, definately remove the metal trim piece that covers the seam between the two garboard planks at the stern. Inspect, clean out any old gunk, and repair whatever as needed. Use a flexible marine caulk (NOT an adhesive such as 3M5200) to bed this as well as the keel. Boat Life Life Caulk is one brand of flexible marine caulking.

You do not need to remove the keel to replace ribs. Note however, that the ribs are screwed and nailed to the keelson from the bottom side. They are screwed and nailed into what you are calling the "cheeks." The ribs are also screwed and nailed from their bottom side into the sister keelsons.

The reason it has been suggested you remove the keel, is because this is the most notorious place for boats such as these to develope leaks. It is a simple fix and a correct means of repair.

Andreas

Thank you for the education.
I will take your advice and remove the keel.
I hope to receive peace of mind and less leaks after a propoer repair.

Ron